In cell biology, the term “canonical pathway” refers to the standard, well-characterized, or classical version of a signal transduction pathway that is typically the most commonly studied and understood version. In the context of signal transduction, when we refer to the canonical Wnt pathway, for example, it typically means the Wnt/β-catenin signaling pathway, which is the main or classical route by which Wnt signaling regulates gene expression.
Key Features of a Canonical Pathway:
Main or classical pathway: It is the primary signaling route through which a ligand (e.g., Wnt, Hedgehog, etc.) exerts its effects on the cell.
Specific downstream components: In a canonical pathway, specific downstream molecules are activated in a well-established sequence (e.g., Wnt binds to its receptor, leading to the stabilization of β-catenin, which translocates to the nucleus to regulate gene expression).
General or broad role: Canonical pathways often have broader and more general roles in regulating various cellular processes such as differentiation, proliferation, and development.
Examples:
Canonical Wnt pathway: Refers to the Wnt/β-catenin pathway, where Wnt signaling stabilizes β-catenin to activate gene transcription.
Canonical TGF-β pathway: Involves the activation of Smad2 and Smad3, which translocate to the nucleus and regulate gene expression.
In contrast, non-canonical pathways are alternative signaling routes that do not follow the classical mechanism and often involve different downstream components and processes, like the Wnt/PCP (planar cell polarity) pathway or Wnt/Ca2+ pathway.
Summary:
The term “canonical pathway” in signal transduction refers to the classical or standard version of a signaling pathway that involves well-defined molecules and mechanisms, widely studied and understood. (ChatGPTの解説）
Mutation of an axonemal dynein affects left-right asymmetry in inversus viscerum mice D M Supp 1, D P Witte, S S Potter, M Brueckner Nature 1997https://pubmed.ncbi.nlm.nih.gov/9353118/
Mechanism of Ciliary Movement || Structure of Cilia || How do Cilia Move? || Mucociliary Clearnace Nonstop Neuron チャンネル登録者数 13.9万人
How Do Cilia and Flagella Move? XVIVO Scientific Animation チャンネル登録者数 5.64万人
Randomization of Left–Right Asymmetry due to Loss of Nodal Cilia Generating Leftward Flow of Extraembryonic Fluid in Mice Lacking KIF3B Motor Protein Shigenori Nonaka ∙ Yosuke Tanaka ∙ Yasushi Okada ∙ Sen Takeda ∙ Akihiro Harada ∙ Yoshimitsu Kanai ∙ Mizuho Kido ∙ Nobutaka Hirokawa* Cell Volume 95, Issue 6p829-837December 11, 1998 https://www.cell.com/cell/fulltext/S0092-8674(00)81705-5
訂正 In this paper (Cell 95[6], 829–837), we described the direction of the nodal cilia rotation as counterclockwise (Figure 6B). However, our recent analyses with higher spatiotemporal resolution revealed that the actual direction is clockwise when seen from the ventral side (above the nodal pit cells). In our previous observation with lower temporal resolution (10 frames per second), the direction of the rapid rotation (∼10 rounds per second) of the nodal cilia was misinterpreted due to the artifact caused by the strobe effect. ‥ For further details, refer to our recent paper Y. Okada et al. (Molecular Cell, 1999, in press). https://www.cell.com/cell/fulltext/S0092-8674(00)80067-7
Nodal Flow and the Generation of Left-Right Asymmetry Cell Volume 125, Issue 1, 7 April 2006, Pages 33-45 https://www.sciencedirect.com/science/article/pii/S009286740600300X このレビュー論文では線毛が動く様子や蛍光ビーズが左側に流れていく様子などを示したわかりやすい動画も掲載されています。
左右軸形成に関する原著論文・総説論文
Molecular anatomy of emerging Xenopus left–right organizer at successive developmental stages Natalia Petri, Alexandra Vetrova, Nikoloz Tsikolia, Stanislav Kremnyov Developmental Dynamics First published: 27 June 2024 https://doi.org/10.1002/dvdy.722
R-Spondin 2 governs Xenopus left-right body axis formation by establishing an FGF signaling gradient Nature Communications Published: 02 February 2024
A dual function of FGF signaling in Xenopus left-right axis formation Isabelle Schneider, Jennifer Kreis, Axel Schweickert, Martin Blum, Philipp Vick Development 01 January 2019 https://journals.biologists.com/dev/article/doi/10.1242/dev.173575/264844/am/A-dual-function-of-FGF-signaling-in-Xenopus-left
Physical limits of flow sensing in the left-right organizer Jun 14, 2017 https://doi.org/10.7554/eLife.25078 Two hypotheses have been proposed for asymmetric flow detection. According to the chemosensing hypothesis, the directional flow establishes a LR asymmetric chemical gradient that is detected by signaling systems which leads to LR asymmetric gene expression and cell responses in the LRO (Okada et al., 2005). The mechanosensing hypothesis, on the other hand, proposes that the LRO cells can detect the mechanical effects of flow. It has been suggested that this mechanosensing is mediated by a particular type of sensory cilia that is able to trigger a local, asymmetric response of the so-called crown cells, which are located at the periphery of the node (mouse LRO) (McGrath et al., 2003; Tabin and Vogan, 2003).
Cerberus–Nodal–Lefty–Pitx signaling cascade controls left–right asymmetry in amphioxus Save Related Papers Chat with paper Guang Li, Xian Liu, Chaofan Xing, +2, and Yiquan Wang PNAS March 20, 2017; 114 (14) 3684-3689 https://www.pnas.org/doi/10.1073/pnas.1620519114
The Left-Right Coordinator: The Role of Vg1 in Organizing Left-Right Axis Formation Cell 3 April 1998; Volume 93, Issue 1, Pages 37-46
On the nature and function of organizers Alfonso Martinez Arias ORCID logo , Ben Steventon ORCID logo Author and article information Development (2018) 145 (5): dev159525. 09 March 2018 https://doi.org/10.1242/dev.159525
上のような解説がありましたが、ニワトリのオーガナイザーに関する総説論文
The avian organizer THOMAS BOETTGER1, HENDRIK KNOETGEN, LARS WITTLER and MICHAEL KESSEL* Int. J. Dev. Biol. 45: 281-287 (2001) https://ijdb.ehu.eus/article/pdf/11291858
Hensen’s node taken from stage 4 to stage 9 quail embryos (the majority was from stage 4) was transplanted to different sides of the axis of stage 4 to stage 6 chick embryos in the area pellucida. The graft differentiated into notochord, neural tissues, somites, and mesenchymal cells, and could also induce the associated host ectoderm to form neural tissue, as described previously (Gallera, 1971; Hornbruch et al., 1979). However, after examining the host embryos in detail, we found that a third axiswas formed in many host embryos besides the secondary axis formed by the grafted Hensen’s node itself (Fig. 8). The third axis was duplicated entirely from host tissue and usually contained a neural tube and somites (Fig. 9). As shown in Table 4, the stage 4 embryo was again the most sensitive to the inductive action of Hensen’s node. Like RA, Hensen’s node grafted on the left side or anterior side of the host axis could cause the duplication of the host axis most frequently (see Table 4). However, Hensen’s node produces more complicated inductive effects than RA. When Hensen’s node was grafted on the right side of the stage 4 host axis, it could also induce a third axis. Stage 5 embryos still responded to the inductive action of grafted Hensen’s node and yielded a third axis. Interestingly, if stage 5 embryos were used as the hosts, only those hosts that received a grafted Hensen’s node on the right side of their axis showed the duplication of the host axis. These results suggested that Hensen’s node might contain another inducing factor that acts like RA but in the opposite direction or might be more potent than the RA beads. However, if stage 6 embryos were used as hosts, grafted Hensen’s node failed to cause axial duplication in the hosts. When primitive streak taken from stage 4 to stage 6 quail embryos was transplanted to stage 4 chick blastoderms as a control experiment, none of the total 12 cases showed host axis duplication (Fig. 8).
DEVELOPMENTAL DYNAMICS 19514%151 (1992) Comparison of Hensen’s Node and Retinoic Acid in Secondary Axis Induction in the Early Chick Embryo YIPING CHEN AND MICHAEL SOLURSH
Gallera, J. (1971) Primary induction in birds. Adv. Morphog. 9:149-180 https://www.sciencedirect.com/science/article/abs/pii/B978012028609650008X
Hornbruch, A,, Summerbell, D., and Wolpert, L. (1979) Somite formation in the early chick embryo following grafts of Hensen’s node. J. Embryol. Exp. Morphol. 51:51-62. https://pubmed.ncbi.nlm.nih.gov/479748/
結論 Hensen’s nodeを異所性に移植すると、ホスト由来の神経組織を含む完全な体軸が形成されることが複数の研究で確認されています。この能力は、特に若い段階のnodeで顕著であり、神経誘導には特定の分子メ THOMAS BOETTGER1, HENDRIK KNOETGEN, LARS WITTLER THOMAS BOETTGER1, HENDRIK KNOETGEN, LARS WITTLER R
The avian organizer THOMAS BOETTGER1, HENDRIK KNOETGEN, LARS WITTLER and MICHAEL KESSEL* Int. J. Dev. Biol. 45: 281-287 (2001) https://ijdb.ehu.eus/article/pdf/11291858
Restoration of the organizer after radical ablation of Hensen’s node and the anterior primitive streak in the chick embryo Delphine Psychoyos, Claudio D. Stern Author and article information Development (1996) 122 (10): 3263–3273. 01 October 1996 https://doi.org/10.1242/dev.122.10.3263 https://journals.biologists.com/dev/article/122/10/3263/38976/Restoration-of-the-organizer-after-radical
Axis development in avian embryos: the ability of Hensen’s node to self-differentiate, as analyzed with heterochronic grafting experiments Takayuki Inagaki, Gary C. Schoenwolf Anat Embryol (1993) 188:1-11 Type-3 experiments. Ten cases of ectopic embryos were obtained from the 13 host blastoderms. In such ectopic embryos, the transplanted nodes self-differentiated into notochord, somites, mesenchyme, and endoderm; the host’s ectoderm typically responded to the grafted cells by forming a neural tube, which often had a morphology characteristic of that of rostral brain levels (i.e., forebrain and midbrain (Figs. 10, 11). https://link.springer.com/article/10.1007/BF00191446 この写真をみても外観を見る限り、きれいな2次軸が形成されるというほどではないようです。組織切片をみて、それぞれの組織への分化が確認できたとのことのようです。
Formation of ectopic neurepithelium in chick blastoderms: Age-related capacities for induction and self-differentiation following transplantation of quail Hensen’s nodes Mark S. Dias, Dr. Gary C. Schoenwolf First published: December 1990 https://doi.org/10.1002/ar.1092280410 本文有料
Neural induction and regionalisation in the chick embryo. Yes 若いヘンゼン結節 (ステージ 2 ～ 4) は前部神経系と後部神経系の両方を誘導しますが、古い結節 (ステージ 5 ～ 6) は後部神経系のみを生成します。 Development Kg Storey et al. 261 Citations 1992
Multiple neural inductions in area opaca by grafts of the Hensen’s node do not retard host chick embryo development. Yes ヘンゼン結節の移植による不透明領域での複数の神経誘導は、宿主のニワトリ胚の発育を遅らせない。 Indian journal of experimental biology G. Guttikar et al. 3 Citations 1993
Neural induction and regionalisation by different subpopulations of cells in Hensen’s node. Unknown 神経誘導能はヘンゼン結節の内側部の胚盤葉上層と中内胚葉に局在しているが、後外側部の深部にはこの能はない。 Development Kate G. Storey et al. 56 Citations 1995
Xenopus laevis; gastrulation through neurulation Oxford Academic (Oxford University Press) チャンネル登録者数 15.6万人
シュペーマンのオーガナイザーの定義
The organizer is a region of the gastrula embryo that can induce the formation of a second neural axis when transplanted to an undifferentiated region of a host gastrula stage embryo (1). https://pmc.ncbi.nlm.nih.gov/articles/PMC27625
原図（A～C) Hamburger, V. 1988. The Heritage of Experimental Embryology: Hans Spemann and the Organizer. Oxford University Press, Oxford. 図引用元：Scotte Gilbert Developmental Biology. 6th edition. Axis Formation in Amphibians: The Phenomenon of the Organizer https://www.ncbi.nlm.nih.gov/books/NBK10101/
シュペーマンのオーガナイザーの今昔に関しては、International Journal of Developmental Biologyの特集号が非常に有益だと思います。2001年の特集号なので、今となってはそこからさらに24年の歳月が経過してはいますが、2001年当時の理解がわかります。Scott Gilbertの総説は非常に読み応えがありました。さすが大著のベストセラーの教科書を書いているだけのことはあります。読ませます。
The International Journal of Developmental Biology Volume 45 > Issue 1 (Special Issue) Cover Vol. 45 N. 1 The Spemann-Mangold Organizer Edited by: Eddy DeRobertis and Juan Aréchaga https://ijdb.ehu.eus/issue/45/1
Antagonism between Smad1 and Smad2 signaling determines the site of distal visceral endoderm formation in the mouse embryo J Cell Biol. 2009 Jan 26;184(2):323–334. doi: 10.1083/jcb.200808044 https://pmc.ncbi.nlm.nih.gov/articles/PMC2654303/
nodalシグナリング：カノニカル経路と非カノニカル経路
nodalはTGF-βファミリーに属するので、カノニカル経路としてはSmadの活性化があります。
Schematic Overview of Nodal and Cripto-1 Signaling Pathways. A) Canonical Nodal signaling using Cripto-1 as a co-receptor. Nodal can also activate this pathway, albeit less efficiently, independently of Cripto-1. B) Cripto-1 Nodal-independent signaling via binding with Glypican-1 and activating src/Ras/raf/PI3K downstream signaling. C) Possible signaling of Cripto-1 through binding to beta-integrins and signaling via FAK-dependent signaling pathway.
2011 Sep 19. Published in final edited form as: Breast Dis. 2008;29:91–103. doi: 10.3233/bd-2008-29110 Emerging Roles of Nodal and Cripto-1: From Embryogenesis to Breast Cancer Progression https://pmc.ncbi.nlm.nih.gov/articles/PMC3175751/#ref-list1
Expression cloning of noggin, a new dorsalizing factor localized to the Spemann organizer in Xenopus embryos W C Smith 1, R M Harland Cell 1992 Sep 4;70(5):829-40. doi: 10.1016/0092-8674(92)90316-5. 要旨より zygotic transcripts are initially restricted to the presumptive dorsal mesoderm and reach their highest levels at the gastrula stage in the dorsal lip of the blastopore (Spemann organizer). In the neurula, noggin is transcribed in the notochord and prechordal mesoderm. The activity of exogenous noggin RNA in embryonic axis induction
Ectopic expression of Xenopus noggin RNA induces complete secondary body axes in embryos of the direct developing frog Eleutherodactylus coqui Development Genes and Evolution Volume 210, pages 21–27, (2000) https://link.springer.com/article/10.1007/PL00008184
Chordin
Xenopus chordin: A Novel Dorsalizing Factor Activated by Organizer-Specific Homeobox Genes Yoshiki Sasai 1, Bin Lu 1, Herbert Steinbeisser 1, Douglas Geissert 1, Linda K Gont 1, Eddy M De Robertis Cell. 1994 Dec 2;79(5):779–790. doi: 10.1016/0092-8674(94)90068-x https://pmc.ncbi.nlm.nih.gov/articles/PMC3082463/ (無料著者原稿）Seventy years after the organizer experiment (Spemann and Mangold, 1924), the quest to isolate the factors released by the organizing centers to recruit neighboring cell continues. 要旨 Microinjection of chordin mRNA induces twinned axes
最初の論文は１９９４年のセル論文でした。
Follistatin
Follistatin, an antagonist of activin, is expressed in the Spemann organizer and displays direct neuralizing activity A Hemmati-Brivanlou 1, O G Kelly, D A Melton Cell. 1994 Apr 22;77(2):283-95. doi: 10.1016/0092-8674(94)90320-4.
Protein Related to DAN and Cerberus Is a Bone Morphogenetic Protein Antagonist That Participates in Ovarian Paracrine Regulation* Journal of Biological Chemistry Volume 279, Issue 22p23134-23141May 2004 https://www.jbc.org/article/S0021-9258(20)66678-9/fulltext
Cerberus is a head-inducing secreted factor expressed in the anterior endoderm of Spemann’s organizer Tewis Bouwmeester, Sung-Hyun Kim, Yoshiki Sasai, Bin Lu & Eddy M. De Robertis Nature volume 382, pages595–601 (1996) 15 August 1996.
最初の報告は１９９６年のネイチャー論文でした。
Head organizer: Cerberus and IGF cooperate in brain induction in Xenopus embryos Yagmur Azbazdar 1, Edgar M Pera 2, Edward M De Robertis 3 Cells Dev . 2023 Dec 16:203897. doi: 10.1016/j.cdev.2023.203897. イントロダクションより Cerberus induces small head structures containing brain, eyes, olfactory placodes, and sometimes a second heart, that are devoid of trunk-tail structures and posterior neural tissue.
Molecular link in the sequential induction of the Spemann organizer: direct activation of the cerberus gene by Xlim-1, Xotx2, Mix.1, and Siamois, immediately downstream from Nodal and Wnt signaling Developmental Biology Volume 257, Issue 1, 1 May 2003, Pages 190-204
Expression of the mouse cerberus-related gene, Cerr1, suggests a role in anterior neural induction and somitogenesis William Shawlot 1, Jian Min Deng 1, Richard R Behringer 1,* Proc Natl Acad Sci U S A. 1998 May 26;95(11):6198–6203. doi: 10.1073/pnas.95.11.6198
Dickkopf (Dkk)
Head inducer Dickkopf-1 is a ligand for Wnt coreceptor LRP6Current Biology Volume 11, Issue 12, 26 June 2001, Pages 951-961 The Wnt family of secreted growth factors initiates signaling via the Frizzled (Fz) receptor and its candidate coreceptor, LDL receptor-related protein 6 (LRP6), presumably through Fz-LRP6 complex formation induced by Wnt. ‥ Dkk-1 is a high-affinity ligand for LRP6 and inhibits Wnt signaling by preventing Fz-LRP6 complex formation induced by Wnt. Dkk-1 binds neither Wnt nor Fz, nor does it affect Wnt-Fz interaction. https://www.sciencedirect.com/science/article/pii/S0960982201002901
Frzb (Frizzled-related protein)
Genes Dev. 1999 Sep 1;13(17):2328–2336. doi: 10.1101/gad.13.17.2328 Axis determination by inhibition of Wnt signaling in Xenopus Keiji Itoh 1, Sergei Y Sokol 1,1 we interfered with Wnt signaling in the embryo using the extracellular domain of XenopusFrizzled 8 (ECD8), which blocks Wnt-dependent activation of a target gene in Xenopus ectodermal explants. Expression of ECD8 in ventral blastomeres resulted in formation of secondary axes この論文は内在的な分子の話ではなく、Wntシグナリングを阻害したときの効果（２次軸形成）をみるための実験
Human Cerberus Prevents Nodal-Receptor Binding, Inhibits Nodal Signaling, and Suppresses Nodal-Mediated Phenotypes PLOS ONE January 201510(1):e0114954 DOI:10.1371/journal.pone.0114954 SourcePubMed LicenseCC BY 4.0 https://www.researchgate.net/publication/271219306_Human_Cerberus_Prevents_Nodal-Receptor_Binding_Inhibits_Nodal_Signaling_and_Suppresses_Nodal-Mediated_Phenotypes
Nodal antagonists regulate formation of the anteroposterior axis of the mouse embryo. Yamamoto M, Saijoh Y, Perea-Gomez A, Shawlot W, Behringer RR, Ang SL, Hamada H, Meno C. Nature. 2004;428:387–392. doi: 10.1038/nature02418. Abstract Patterning of the mouse embryo along the anteroposterior axis during body plan development requires migration of thedistal visceral endoderm (DVE) towards the future anterior side by a mechanism that has remained unknown. Here we show that Nodal signalling and the regionalization of its antagonists are required for normal migration of the DVE. Whereas Nodal signalling provides the driving force for DVE migration by stimulating the proliferation of visceral endoderm cells, the antagonists Lefty1 and Cerl determine the direction of migration by asymmetrically inhibiting Nodal activity on the future anterior side. https://www.nature.com/articles/nature02418 本文読めた To confirm the role of Nodal antagonists in A–P patterning, we analysed mutant mice lacking Lefty1 or Cerl. Lefty1-/- (ref. 13) and Cerl-/- (refs 6, 14, 15) embryos undergo normal gastrulation, whereas Cerl-/-,Lefty1-/- embryos develop multiple primitive streaks8, suggestive of functional redundancy between Lefty1 and Cerl. We first examined expression of the AVE marker Hex (Fig. 5a, b, h, i). The Hex expression domain was expanded slightly in Cerl-/- and Lefty1-/- mutants (data not shown) and markedly in the Cerl-/-,Lefty1-/- double mutant (Fig. 5b, i), in which cells positive for Hex transcripts occupied the entire anterior half of the VE at E6.5 (n = 4). These results reveal that the Nodal antagonists restrict the size or location of the AVE, perhaps by inhibiting the proliferation of AVE cells.
a Following implantation, Nodal is expressed throughout the epiblast and plays a role in specifying the underlying distal visceral endoderm (DVE). The DVE in response secretes Nodal inhibitors Cerberus and Lefty, generating a posterior-distal gradient of Nodal and forming one of the earliest patterns in the embryo. ExE extra-embryonic ectoderm, VE visceral endoderm, P-D proximal-distal. b The DVE migrates anteriorly to become the anterior visceral endoderm (AVE) concentrating Nodal further to the proximal and newly formed posterior axis by continued secretion of Nodal inhibitors. A-P anterior-posterior. c In a process that requires high levels of Nodal, gastrulation begins with formation of the early primitive streak. Epiblast cells undergo EMT and migrate with subsequent differentiation into mesoderm and endoderm lineages. Inset: Pro-Nodal expressed in the epiblast upregulates Furin, Pace4, and BMP4 within the ExE. Furin and Pace4 subsequently process pro-Nodal and BMP4 stimulates Wnt3 signaling in the epiblast. Wnt3 acts on a Nodal proximal epiblast enhancer to increase Nodal expression. Nodal also amplifies its own signal through an enhancer region in intron 1 stimulated by Smad2/3-FoxH1, collectively increasing levels of Nodal in the proximal epiblast.
Plasticity underlies tumor progression: Role of Nodal signaling March 2016 Cancer and Metastasis Reviews 35(1) DOI:10.1007/s10555-016-9605-5 https://www.researchgate.net/figure/Role-of-Nodal-in-the-early-mouse-embryo-a-Following-implantation-Nodal-is-expressed_fig8_297661953
Nodal signaling from the visceral endoderm is required to maintain Nodal gene expression in the epiblast and drive AVE migration Amit Kumar 1,†, Margaret Lualdi 2, George T Lyozin 3, Prashant Sharma 1, Jadranka Loncarek 1, Xin-Yuan Fu 4, Michael R Kuehn Dev Biol. Author manuscript; available in PMC: 2016 Apr 1. Published in final edited form as: Dev Biol. 2014 Dec 20;400(1):1–9. doi: 10.1016/j.ydbio.2014.12.016 https://pmc.ncbi.nlm.nih.gov/articles/PMC4806383/ 要旨より The Nodal gene is expressed in both the VE and in the pluripotent epiblast, which gives rise to the germ layers. Previous findings have provided conflicting evidence as to the relative importance of Nodal signaling from the epiblast vs. VE for AP patterning.
Molecular Nature of Spemann’s Organizer: the Role of the Xenopus Homeobox Gene goosecoid Ken W Y Cho 1,*, Bruce Blumberg 1, Herbert Steinbeisser 1, Eddy M De Robertis 1 Cell. 1991 Dec 20;67(6):1111–1120. doi: 10.1016/0092-8674(91)90288-a https://pmc.ncbi.nlm.nih.gov/articles/PMC3102583/ 著者原稿無料PDF https://linkinghub.elsevier.com/retrieve/pii/009286749190288A 本文有料
Nasal and pharyngeal abnormalities caused by the mouse goosecoid gene mutationBiochem Biophys Res Commun . 1997 Apr 7;233(1):161-5. doi: 10.1006/bbrc.1997.6315. https://pubmed.ncbi.nlm.nih.gov/9144415/
Lim-1
Role of the LIM class homeodomain protein Xlim-1 in neural and muscle induction by the Spemann organizer in Xenopus M Taira 1, H Otani, J P Saint-Jeannet, I B Dawid Nature . 1994 Dec 15;372(6507):677-9. doi: 10.1038/372677a0. https://www.nature.com/articles/372677a0
Requirement for Lim1 in head-organizer function W Shawlot 1, R R Behringer Nature 1995 Mar 30;374(6521):425-30. doi: 10.1038/374425a0. Embryos homozygous for the null allele lacked anterior head structures but the remaining body axis developed normally.
Functional domains of the LIM homeodomain protein Xlim-1 involved in negative regulation, transactivation, and axis formation in Xenopus embryos I Hiratani 1, T Mochizuki, N Tochimoto, M Taira Dev Biol . 2001 Jan 15;229(2):456-67. doi: 10.1006/dbio.2000.9986.
Sequential roles for Otx2 in visceral endoderm and neuroectoderm for forebrain and midbrain induction and specification M Rhinn 1, A Dierich, W Shawlot, R R Behringer, M Le Meur, S L Ang Development . 1998 Mar;125(5):845-56. doi: 10.1242/dev.125.5.845.
nodal
Nodal is a novel TGF-beta-like gene expressed in the mouse node during gastrulation X Zhou 1, H Sasaki, L Lowe, B L Hogan, M R Kuehn Nature . 1993 Feb 11;361(6412):543-7. doi: 10.1038/361543a0. 本文有料 要旨より Here we isolate a candidate for the mutated gene which encodes a new member of the transforming growth factor-beta (TGF-beta) superfamily. Expression is first detected in primitive streak-stage embryos at about the time of mesoderm formation. It then becomes highly localized in the node at the anterior of the primitive streak. This region is analogous to chick Hensen’s node and Xenopus dorsal lip (Spemann’s organizer), which can induce secondary body axes when grafted into host embryos (reviewed in refs 5 and 6).
ノーダル遺伝子の同定もネイチャー論文でした。
Nodal signalling in the epiblast patterns the early mouse embryo J Brennan 1, C C Lu, D P Norris, T A Rodriguez, R S Beddington, E J Robertson Nature . 2001 Jun 21;411(6840):965-9. doi: 10.1038/35082103. 要約より Nodal signals from the epiblast also pattern the visceral endoderm by activating the Smad2-dependent pathway required for specification of anterior identity in overlying epiblast cells.
ノーダルのマウス初期発生における役割の解析もネイチャー論文になりました。
Nodal signaling from the visceral endoderm is required to maintain Nodal gene expression in the epiblast and drive AVE migration Dev Biol. 2014 Dec 20;400(1):1–9. doi: 10.1016/j.ydbio.2014.12.016 https://pmc.ncbi.nlm.nih.gov/articles/PMC4806383/ conditional mutagenesis of the Nodal gene specifically within the VE leads to reduced Nodal expression levels in the epiblast and incomplete or failed AVE migration
Nodal Signaling Activates Differentiation Genes During Zebrafish Gastrulation James T Bennett 1, Katherine Joubin 1,3, Simon Cheng 1,2, Pia Aanstad 4,5, Ralf Herwig 4, Matthew Clark 3,4, Hans Lehrach 4, Alexander F Schier 1,6 Dev Biol. 2007 Jan 12;304(2):525–540. doi: 10.1016/j.ydbio.2007.01.012 https://pmc.ncbi.nlm.nih.gov/articles/PMC1885460/
Nodal specifies embryonic visceral endoderm and sustains pluripotent cells in the epiblast before overt axial patterning Development . 2006 Jul;133(13):2497-505. doi: 10.1242/dev.02413. Epub 2006 May 25. https://pubmed.ncbi.nlm.nih.gov/16728477/ (B,C) The PrE also expresses the DVE markers Lefty1 (B), Hex and a HexP-GFP reporter transgene(C), whereas Cer1 mRNA is below detectable levels (B).Lefty1 and Hex transcripts are clearly downregulated between E5.0 and 5.25 before they reappear together with Cer1mRNA in the most distal VE cells at E5.5. https://journals.biologists.com/dev/article/133/13/2497/52434/Nodal-specifies-embryonic-visceral-endoderm-and
Multiple roles for Nodal in the epiblast of the mouse embryo in the establishment of anterior-posterior patterning Cindy C Lu 1, Elizabeth J Robertson Dev Biol . 2004 Sep 1;273(1):149-59. doi: 10.1016/j.ydbio.2004.06.004. https://pubmed.ncbi.nlm.nih.gov/15302604/
The Foxh1-dependent autoregulatory enhancer controls the level of Nodal signals in the mouse embryo Dominic P. Norris, Jane Brennan, Elizabeth K. Bikoff, Elizabeth J. Robertson 15 July 2002 https://journals.biologists.com/dev/article/129/14/3455/41736/The-Foxh1-dependent-autoregulatory-enhancer
nodal expression in the primitive endoderm is required for specification of the anterior axis during mouse gastrulation I Varlet 1, J Collignon, E J Robertson Development . 1997 Mar;124(5):1033-44. doi: 10.1242/dev.124.5.1033.
A Xenopus nodal-related gene that acts in synergy with noggin to induce complete secondary axis and notochord formation K. D. Lustig, K. Kroll, E. Sun, R. Ramos, H. Elmendorf, M. W. Kirschner Author and article information Development (1996) 122 (10): 3275–3282. https://journals.biologists.com/dev/article/122/10/3275/38985/A-Xenopus-nodal-related-gene-that-acts-in-synergy
Cripto-independent Nodal signaling promotes positioning of the A-P axis in the early mouse embryo. G. Liguori, A. Borges, A. Borges+9 more · Developmental Biology Volume 315, Issue 2, 15 March 2008, Pages 280-289 2008年3月15日 https://www.sciencedirect.com/science/article/pii/S0012160607016351
その他の論文
The HPE gene CRIPTO/oep physically interacts with the ligand–receptor complex, and is required for Nodal signal transduction, positioning this protein as a Nodal co-receptor [40–43]. https://en.wikipedia.org/wiki/Nodal_signaling_pathway
EGF-CFC proteins are membrane bound extracellular factors that serve as essential cofactor in Nodal signaling and in vertebrate development as a whole. This family of cofactors includes One-eyed Pinhead (oep) in Zebrafish, FRL1 in Xenopus, and Cripto and Criptic in mouse and human. https://en.wikipedia.org/wiki/Nodal_signaling_pathway
the activity of Nodal requires epidermal growth factor-Cripto/FRL-1/Cryptic (EGF-
CFC) co-receptors such as Cripto and Cryptic (Tdgf1 and Cfc1 –
Mouse Genome Informatics) (Reissmann et al., 2001; Yan et al.,
2002; Yeo and Whitman, 2001). In particular, membrane-bound
Cripto appears to recruit Nodal to an activin receptor complex
composed of a dimer of the type I serine-threonine receptor Alk4
(Acvr1b) and a dimeric type II activin receptor, either ActRII or
ActRIIB (Acvr2a or Acvr2b – Mouse Genome Informatics). https://www.researchgate.net/publication/51591179_Regulation_of_extra-embryonic_endoderm_stem_cell_differentiation_by_Nodal_and_Cripto_signaling
Mature Nodal binds to the Activin receptors I and II and the co-receptor Cripto/Criptic and phosphorilates Smad2 /3. https://en.wikipedia.org/wiki/Nodal_signaling_pathway
The orphan receptor ALK7 and the Activin receptor ALK4 mediate signaling by Nodal proteins during vertebrate development. document Genes & developmentEva Reissmann et al.
Journal of Japanese Biochemical Society 89(2): 145-153 (2017) doi:10.14952/SEIKAGAKU.2017.890145 TGF-βシグナルを抑制するTMEPAIファミリー 2017年4月25日 https://seikagaku.jbsoc.or.jp/10.14952/SEIKAGAKU.2017.890145/data/index.html
Hhex has been found to be an important transcription factor in embryogenesis because Hhex−/− mice display embryonic lethality starting at embryonic day E10.5 to E11.5 due to impaired forebrain, liver, and thyroid development.8–10
Hhex expression is initially seen in the blood islands of the yolk sac at the same time Flk-1 expression is initiated.9
AVE protein expression and visceral endoderm cell behavior during anterior–posterior axis formation in mouse embryos: Asymmetry in OTX2 and DKK1 expression Hideharu Hoshino, Go Shioi, Shinichi Aizawa Developmental Biology Volume 402, Issue 2, 15 June 2015, Pages 175-191 Developmental Biology https://www.sciencedirect.com/science/article/pii/S0012160615001748
An anterior signalling centre in Xenopus revealed by the homeobox gene XHex C.Michael Jones1 jonesm@icr.ac.uk ∙ Joanne Broadbent2 ∙ Paul Q. Thomas3 ∙ James C. Smith4 ∙ Rosa S.P. Beddington3 Current Biology Volume 9, Issue 17p946-S1-954September 09, 1999 https://www.cell.com/current-biology/fulltext/S0960-9822(99)80421-7 (f) Animal pole view of stage 10.5 gastrula shows that cerberus expression is detected in a wider domain of the deep endoderm than is XHex (b). 背景より In Xenopus, the putative head inducer cerberus is expressed initially in deep endodermal cells adjacent to the involuting tissues of Spemann’s organiser [7]. Is this tissue the equivalent of the anterior visceral endoderm in the early mouse and rabbit embryo? Here, we have addressed this question by analysing the expression and function of XHex, the Xenopus cognate of murine Hex (also known as Prh) [8,9].
DEVからAVEへの細胞移動
Nodal signaling from the visceral endoderm is required to maintain Nodal gene expression in the epiblast and drive AVE migration Dev Biol. 2014 Dec 20;400(1):1–9. doi: 10.1016/j.ydbio.2014.12.016 https://pmc.ncbi.nlm.nih.gov/articles/PMC4806383/
Induction and migration of the anterior visceral endoderm is regulated by the extra-embryonic ectoderm Tristan A Rodriguez 1, Shankar Srinivas, Melanie P Clements, James C Smith, Rosa S P Beddington Development . 2005 Jun;132(11):2513-20. doi: 10.1242/dev.01847. Epub 2005 Apr 27.
中胚葉誘導と体軸形成との関係
Mesoderm induction and axis formation are tightly correlated processes in developmental biology, particularly during early embryogenesis. Here’s how they are interconnected:
Mesoderm Induction: This process begins during gastrulation, where signaling molecules like Nodal, BMP, and Wnt help induce the formation of mesoderm from the epiblast. The mesoderm gives rise to various tissues, including muscles, bones, and the circulatory system.
Organizer and Axis Formation: The Spemann-Mangold organizer (in amphibians) or the Hensen’s node (in mammals) plays a central role in both mesoderm induction and the formation of the body axis. The organizer secretes BMP antagonists (such as Chordin, Noggin, and Follistatin) that create a dorsal-ventral gradient essential for patterning the mesoderm and establishing the anterior-posterior and dorsal-ventral axes.
Signaling Pathways:
Nodal signaling: Initiates mesoderm formation and is essential for the primitive streak formation, which defines the body axis (anterior-posterior).
BMP inhibition by molecules like Chordin and Noggin, secreted from the organizer, is crucial for dorsalization and axis formation. Without this inhibition, mesoderm would not form correctly, leading to a lack of proper axis formation.
In summary, mesoderm induction and axis formation are closely linked, with key signaling molecules from the organizer region guiding both the formation of mesodermal tissue and the establishment of the body axis during early development.
In mice, around embryonic day (E) 6.0, at the time when gastrulation begins, mouse PGCs (mPGCs) are specified as about 10 cells in the most posterior part of epiblast, the cup-shaped simple pluripotent epithelium, from which all of the embryonic portion are derived (Fig. 1.1). This process occurs in response to bone morphogenetic protein 4 (BMP4) [25] produced by the extraembryonic ectoderm (ExE), an extraembryonic part of conceptus in intimate contact with the edge of the epiblast (Fig. 1.1). https://www.sciencedirect.com/topics/engineering/extraembryonic-ectoderm
Migrating mesoderm cells self-organize into a dynamic meshwork structure during chick gastrulation Yukiko Nakaya, Mitsusuke Tarama, Sohei Tasaki, Ayako Isomura, View ORCID ProfileTatsuo Shibata doi: https://doi.org/10.1101/2022.09.08.507227 Posted September 09, 2022. https://www.biorxiv.org/content/10.1101/2022.09.08.507227v1.full
Cell movement during chick primitive streak formation Developmental Biology Volume 296, Issue 1, 1 August 2006, Pages 137-149 細胞の動きを示したsupplementary movie 動画がいくつかあります https://www.sciencedirect.com/science/article/pii/S0012160606007299
Cell Movement Patterns during Gastrulation in the Chick Are Controlled by Positive and Negative Chemotaxis Mediated by FGF4 and FGF8 Developmental Cell Volume 3, Issue 3, September 2002, Pages 425-437 https://www.sciencedirect.com/science/article/pii/S1534580702002563 細胞移動の軌跡を示した動画がいくつかあります。FGF8とFGF4の役割についても非常にわかりやすい実験結果
Self-Organizing Properties of Mouse Pluripotent Cells Initiate Morphogenesis upon Implantation Cell Volume 156, Issue 5p1032-1044February 27, 2014 https://www.cell.com/fulltext/S0092-8674%2814%2900075-0
AEV特異的マーカータンパク質の早期の時期における発現
AVE protein expression and visceral endoderm cell behavior during anterior-posterior axis formation in mouse embryos: Asymmetry in OTX2 and DKK1 expression. Developmental biology Hideharu Hoshino et al. 36 citations 2015 https://www.sciencedirect.com/science/article/pii/S0012160615001748 AVEマーカータンパク質のステージE4.5の時期の発現
Nodal signaling from the visceral endoderm is required to maintain Nodal gene expression in the epiblast and drive DVE/AVE migration Developmental Biology Volume 400, Issue 1, 1 April 2015, Pages 1-9 Developmental Biology https://pdf.sciencedirectassets.com/272543/1-s2.0-S0012160615X00054/1-s2.0-S0012160614006460/main.pdf
Hex: a homeobox gene revealing peri-implantation asymmetry in the mouse embryo and an early transient marker of endothelial cell precursors Development . 1998 Jan;125(1):85-94. doi: 10.1242/dev.125.1.85. https://journals.biologists.com/dev/article/125/1/85/39778/Hex-a-homeobox-gene-revealing-peri-implantation
From fertilization to gastrulation: axis formation in the mouse embryo. Curr Opin Genet Dev . 2001 Aug;11(4):384-92. DOI:10.1016/S0959-437X(00)00208-2Corpus ID: 17925624
Vertebrate Axial Patterning: From Egg to Asymmetry. Advances in Experimental Medicine and Biology, 01 Jan 2017, 953:209-306 https://doi.org/10.1007/978-3-319-46095-6_6 PMID: 27975274 PMCID: PMC6550305 https://europepmc.org/article/pmc/pmc6550305
DVEがAVEの位置に移動するためにはnodalシグナルが必要なようです。
Nodal signaling from the visceral endoderm is required to maintain Nodal gene expression in the epiblast and drive DVE/AVE migration Developmental Biology Volume 400, Issue 1, 1 April 2015, Pages 1-9 Developmental Biology https://pdf.sciencedirectassets.com/272543/1-s2.0-S0012160615X00054/1-s2.0-S0012160614006460/main.pdf
AVEで発現する遺伝子
AVE protein expression and visceral endoderm cell behavior during anterior-posterior axis formation in mouse embryos: Asymmetry in OTX2 and DKK1 expression. Developmental biology Hideharu Hoshino et al. 36 citations 2015 https://www.sciencedirect.com/science/article/pii/S0012160615001748 ステージE6.5でのAVEにおける特異的なタンパク質の発現
Axis Development and Early Asymmetry in Mammals Cell Volume 96, Issue 2p195-209 January 22, 1999 https://www.cell.com/fulltext/S0092-8674%2800%2980560-7
At the blastocyst stage, the polar TE lies adjacent to the epiblast and is fated to form the extraembryonic ectoderm and ectoplacental cone, which will subsequently form the fetal portion of the placenta, whereas the mural TE initially encloses the blastocyst cavity and eventually forms the outer layer of the parietal yolk sac.
Between E5.5 and E6.0, the proamniotic cavity expands to the extraembryonic ectoderm, forming the proamniotic canal.
Axis Development and Early Asymmetry in Mammals Cell Volume 96, Issue 2p195-209January 22, 1999 https://www.cell.com/fulltext/S0092-8674%2800%2980560-7
The role of BMP4 signaling in trophoblast emergence from pluripotencyCellular and Molecular Life Sciences 25 July 2022 Volume 79, article number 447, (2022)
Fig.1 Whole-mount in situ hybridisation analysis showing asymmetrical Hex expression in the visceral endoderm of pregastrulation stage embryos. (A-C) 4.5 dpc blastocysts showing Oct-4 expression (A) in the inner cell mass and Hex expression (B,C) in the primitive endoderm (black arrowhead). (D,E) Hex expression (black arrowhead) in the distal tip visceral endoderm of 5.5 dpc embryos. Note that the Hex expression domain is immediately proximal to the distal tip in the slightly older embryo shown in E. (F,G) Double in situ hybridisation analysis ofHex (black arrowhead) and T (white arrowhead) at 6.0 dpc (F) and 6.5 dpc (G). Hex expression at 6.0 dpc is clearly asymmetrical within the endoderm prior to the accumulation of T transcripts to the nascent primitive streak at the posterior pole of the embryo (G). Bar, 40 μm (A-C); 50 μm (D); 60 μm (E-G).
Hex: a homeobox gene revealing peri-implantation asymmetry in the mouse embryo and an early transient marker of endothelial cell precursors Development (1998) 125 (1): 85–94. 01 January 1998
In humans, a structure equivalent to the mouse extraembryonic ectoderm is not thought to form.
Pluripotent Stem Cells Susana M. Chuva de Sousa Lopes, Christine L. Mummery, in Handbook of Stem Cells (Second Edition) , 2013 https://www.sciencedirect.com/topics/engineering/extraembryonic-ectoderm
In the post-implantation mouse embryo, formation of the PS and initiation of germ layer formation are driven by signaling activities emanating from the extraembryonic tissues such as the extraembryonic ectoderm, which gives rise to chorionic ectoderm, and visceral endoderm and from within the epiblast. However, in primates, there is no clear equivalent to the TE-derived extraembryonic ectoderm of the mouse, which is a major source of BMP to induce gastrulation and primitive-streak formation. In humans and nonhuman primates, the amnion (amniotic epithelium) is reputed to behave like a signaling center of BMP activity to induce the differentiation of mesoderm in the Cynomolgus embryonic disc and the human PASE (Shao et al., 2017; Yang et al., 2021; Zheng et al., 2019). https://www.cell.com/developmental-cell/pdf/S1534-5807(21)01042-X.pdf
そうなるとヒトの場合は、どこから最初のシグナルが来るの？という疑問が湧きます。
Early mouse embryonic development. As described in the text, the blastocyst at 3.5 dpc consists of two tissues: the inner cell mass and trophectoderm. At 4.5 dpc the primitive endoderm is formed and the embryo starts to implant into the uterine wall. By 5.5 dpc, the embryo is cup-shaped https://www.researchgate.net/figure/Early-mouse-embryonic-development-As-described-in-the-text-the-blastocyst-at-35-dpc_fig1_228357767
BMP4シグナル
Front Cell Dev Biol. 2024 Apr 22;12:1386739. doi: 10.3389/fcell.2024.1386739 A comprehensive review: synergizing stem cell and embryonic development knowledge in mouse and human integrated stem cell-based embryo models https://pmc.ncbi.nlm.nih.gov/articles/PMC11074781/
上皮ー間葉転換 EMT
Basal delamination during mouse gastrulation primes pluripotent cells for differentiation https://pmc.ncbi.nlm.nih.gov/articles/PMC7616279/
Distinct predictive performance of Rac1 and Cdc42 in cell migration ScienceVio チャンネル登録者数 8620人 Published: 04 December 2015 Distinct predictive performance of Rac1 and Cdc42 in cell migration Masataka Yamao, Honda Naoki, Katsuyuki Kunida, Kazuhiro Aoki, Michiyuki Matsuda & Shin Ishii Scientific Reports volume 5, Article number: 17527 (2015)
ニワトリ胚の中胚葉細胞の移動経路
Cell movement patterns during gastrulation in the chick are controlled by positive and negative chemotaxis mediated by FGF4 and FGF8 Dev Cell . 2002 Sep;3(3):425-37. doi: 10.1016/s1534-5807(02)00256-3. https://www.cell.com/developmental-cell/fulltext/S1534-5807(02)00256-3 蛍光標識した 原始結節(node)の移植片の細胞の移動経路を経時的に観察
Fates and migratory routes of primitive streak cells in the chick embryo Delphine Psychoyos, Claudio D. Stern Author and article information Development (1996) 122 (5): 1523–1534. 01 May 1996 https://journals.biologists.com/dev/article/122/5/1523/39034/Fates-and-migratory-routes-of-primitive-streak
ニワトリ胚のFGFの役割
FGF signalling through RAS/MAPK and PI3K pathways regulates cell movement and gene expression in the chicken primitive streak without affecting E-cadherin expression Katharine M Hardy, Tatiana A Yatskievych, JH Konieczka, Alexander S Bobbs & Parker B Antin BMC Developmental Biology volume 11, Article number: 20 (2011) Published: 21 March 2011 https://bmcdevbiol.biomedcentral.com/articles/10.1186/1471-213X-11-20
Gene expression pattern Expression of Fgf4 during early development of the chick embryo Mechanisms of Development Volume 85, Issues 1–2, 1 July 1999, Pages 189-192 https://www.sciencedirect.com/science/article/pii/S0925477399000933
FGF Signaling Regulates Mesoderm Cell Fate Specification and Morphogenetic Movement at the Primitive Streak Developmental Cell Volume 1, Issue 1p37-49July 2001 https://www.cell.com/developmental-cell/fulltext/S1534-5807(01)00017-X
マウス胚のFGFの役割
Targeted disruption of Fgf8 causes failure of cell migration in the gastrulating mouse embryo Genes & Dev. 1999. 13: 1834-1846 https://genesdev.cshlp.org/content/13/14/1834/F1.expansion.html
AK Hadjantonakis: Cell lineage specification & tissue morphogenesis in the early mouse embryo. Genetics Society of America チャンネル登録者数 2040人
CerberusやDickkopfによるWntシグナリングの阻害
Heads or tails: Wnts and anterior–posterior patterning Terry P Yamaguchi Current Biology Volume 11, Issue 17pR713-R724 September 04, 2001 https://www.cell.com/current-biology/fulltext/S0960-9822%2801%2900417-1
nordal
The ability of the Nodal pathway to induce both mesoderm specification and axis extension in explants is consistent with its role in vivo, where Nodal is necessary for both (37–40). For example, mouse embryos mutant for Nodal signaling components fail to gastrulate entirely (41). Zebrafish embryos lacking all Nodal function – through loss of the coreceptor Tdgf1/Cripto (MZoep-/-) (40), ligands (sqt-/-cyc-/-) (38), or downstream effector Smad2 (MZsmad2-/-) (42) – similarly lack all endoderm and most mesoderm and undergo abnormal gastrulation movements resulting in a severely shortened AP axis.
Temporal dynamics of BMP/Nodal ratio drive tissue-specific gastrulation morphogenesis https://www.biorxiv.org/content/10.1101/2024.02.06.579243v1.full
Eomes, Criptなどのシグナル分子
From fertilization to gastrulation: axis formation in the mouse embryo. Curr Opin Genet Dev . 2001 Aug;11(4):384-92. DOI:10.1016/S0959-437X(00)00208-2Corpus ID: 17925624
a–l, Whole-mount in situ hybridization analysis. a, Uniform symmetric staining in the epiblast at 5.5 d.p.c.; b, a cross section shows lack of expression in the visceral endoderm. c, d, Proximal–distal gradient of expression in the epiblast. e, Sagittal section of d. f, g, Expression shifts caudally before the onset of gastrulation at 6.5 d.p.c. h, Cross-section of g shows widespread expression in the epiblast and no expression in the visceral endoderm. i, Mid-streak stage; j, cross-section shows intense staining in the newly formed embryonic mesoderm. k, l, Expression persists in the primitive streak and head process at the neural plate stage. m–r, β-Galactosidase staining of Cripto heterozygotes. m, n, Uniform staining in the epiblast before gastrulation. o, Sagittal section shows proximal–distal graded staining just before gastrulation. p, Early-streak stage embryo, and q, cross-section. r, Early neural-plate-stage embryo: note more intense staining at distal end of the primitive streak. In all panels, anterior faces to the left when anterior–posterior orientation can be identified; staging before primitive streak formation is approximate. Scale bars, 0.05 mm. A, anterior; D, distal; ep, epiblast; hp, head process; m, mesoderm; P, posterior; Pr, proximal; ps, primitive streak (bar denotes extent of streak); ve, visceral extra-embryonic endoderm.
Cripto is required for correct orientation of the anterior–posterior axis in the mouse embryo Nature volume 395, pages702–707 (1998) Published: 15 October 1998 https://www.nature.com/articles/27215
The Dynamics of Morphogenesis in the Early Mouse Embryo. Cold Spring Harbor Perspectives in Biology, 26 Jun 2014, 7(11):a015867 https://doi.org/10.1101/cshperspect.a015867 PMID: 24968703 PMCID: PMC4277506
Blastocyst lineage formation, early embryonic asymmetries and axis patterning in the mouse J. Rossant, P. Tam Published in Development 1 March 2009 Biology DOI:10.1242/dev.017178Corpus ID: 207151163
Vg1
Molecular mechanisms controlling the biogenesis of the TGF-β signal Vg1 PNAS October 16, 2023 120 (43) e2307203120 https://www.pnas.org/doi/10.1073/pnas.2307203120 The TGF-beta signals Nodal and Vg1 (Dvr1/Gdf3) play crucial roles in vertebrate development (1, 2), including the induction of mesendoderm and the generation of left-right asymmetry (3–17). For example, secreted Vg1-Nodal heterodimers induce a gradient of signaling that patterns the embryonic mesendoderm in zebrafish (10). Vg1-Nodal heterodimers exert their effects as ligands for a receptor complex that comprises Activin serine-threonine kinase receptors and an essential coreceptor called Oep (Tdgf1/CRIPTO) (18–20). Activated ligand-receptor complexes catalyze phosphorylation of Smad2 (pSmad2), which accumulates in the nucleus to induce the expression of mesendodermal genes (21).
中胚葉マーカー分子
Brachyury (TBXT (human), also T/Bra (mouse))
TBXT dose sensitivity and the decoupling of nascent mesoderm specification from EMT progression in 2D human gastruloids bioRxiv [Preprint]. 2023 Nov 9:2023.11.06.565933. [Version 2] doi: 10.1101/2023.11.06.565933
The T gene is necessary for normal mesodermal morphogenetic cell movements during gastrulation Development (1995) 121 (3): 877–886. the phenotype of homozygous mutant mouse embryos does not obviously correlate with an essential function for T during the early stages of gastrulation, since development rostral to the forelimb bud appears grossly normal. Only in more caudal trunk regions and in later embryos is the notochord missing and other mesodermal derivatives deficient or defective (Herrmann, 1992; Beddington et al., 1992; Rashbass et al., 1994). https://journals.biologists.com/dev/article/121/3/877/38504/The-T-gene-is-necessary-for-normal-mesodermal 機能的に重要そうなのにノックアウトマウスの表現型は非常にささやか。
A cell autonomous function of Brachyury in T/T embryonic stem cell chimaeras Nature volume 353, pages348–351 (1991) https://www.nature.com/articles/353348a0
Expression pattern of the mouse T gene and its role in mesoderm formation.Nature, 343(6259), 657–659. 10.1038/343657a0 Wilkinson D. G., Bhatt S., & Herrmann B. G. (1990). https://www.nature.com/articles/343657a0 有料
Effects of the brachyury (T) mutation on morphogenetic movement in the mouse embryo Dev Biol . 1981 Oct 30;87(2):242-8. doi: 10.1016/0012-1606(81)90147-0. 有料
抗体―薬物複合体開発の発展と現状 Drug Delivery System 34―1, 2019 https://www.jstage.jst.go.jp/article/dds/34/1/34_10/_pdf 抗体と薬物を共有結合で結合し、かつ、細胞内で、発現上昇している酵素などで切断するリンカーを組み入れる必要がある。
Monomethyl auristatin antibody and peptide drug conjugates for trimodal cancer chemo-radio-immunotherapy Published: 05 July 2022 https://www.nature.com/articles/s41467-022-31601-z
特許情報
http://datespriority:2009/03/06 Antibody drug conjugated that bind monomethyl auristatin e (mmae), compositions comprisimg the same and uses thereof https://pubchem.ncbi.nlm.nih.gov/patent/IL-214983-A0
Conjugate of monomethyl auristatin F and trastuzumab and its use for the treatment of cancer https://pubchem.ncbi.nlm.nih.gov/patent/US-9669106-B2
Yes, it is possible to make a patent claim that covers a method of using an antibody-drug conjugate (ADC) composed of a specific antibody (XX) and a specific drug payload (YY) for the treatment of a particular disease (ZZ). This type of patent claim is known as a “method of treatment” claim. In such claims, the inventors can specify the use of a particular composition (like an ADC) to treat a disease by detailing how the composition interacts with the disease target, the dosages, and other relevant therapeutic parameters.
Key Points About Method of Treatment Claims in ADC Patents:
Composition and Mechanism: These claims often describe how the antibody targets a specific antigen on cancer cells and how the cytotoxic drug component, once delivered, kills the cancer cells. For example, an ADC that combines antibody XX (which targets a specific receptor) and drug YY (a cytotoxic agent) could be claimed for the treatment of disease ZZ (such as a specific type of cancer).
Specificity of Antigen Target: You can claim that the antibody binds to a specific antigen that is overexpressed on diseased cells, such as CD33 in leukemia or HER2 in breast cancer. These antigen-targeting claims are critical because they define the ADC’s selectivity and therapeutic application.
Therapeutic Indications: The claim may specify the therapeutic indication, such as using the ADC for treating particular types of cancer, autoimmune diseases, or other conditions where the antibody target is expressed on disease-causing cells. For example, the patent could claim the method of using an ADC that targets HER2 for treating HER2-positive breast cancer Empower Innovation.
Dosage and Administration: These claims can also specify the dosage regimen, the route of administration (such as intravenous infusion), and how the therapy is applied in a clinical setting. The inclusion of such details helps to establish the uniqueness of the method of treatment claim.
Examples of Method of Treatment Claims:
HER2-Positive Cancer Treatment: A patent might claim the use of an ADC where the antibody targets the HER2 antigen and the cytotoxic drug is a maytansinoid, for treating HER2-positive cancers such as breast or gastric cancers.
Blood Cancer Treatment: Another patent might claim the use of an ADC targeting CD22 for the treatment of B-cell lymphomas.
Legal Considerations:
In some jurisdictions (such as the United States), method of treatment claims are allowed, but the specific rules may differ in other regions, such as the European Union, where method of treatment claims are subject to stricter scrutiny. In Europe, “Swiss-type” claims (use of a substance for the manufacture of a medicament) are often used instead.
In conclusion, making a patent claim that specifies using a particular antibody (XX) and drug (YY) for treating a particular disease (ZZ) is not only possible but a common strategy in the patenting of ADCs and other targeted therapies.
日本の事情
In Japan, method of treatment claims are generally not accepted. The Japanese Patent Office (JPO) follows the principle that medical treatment methods for humans cannot be patented. This includes methods of surgery, therapy, and diagnosis, as they are considered to fall under the scope of activities that should remain free from exclusive rights to ensure public health. This is similar to the approach taken by the European Patent Office (EPO)
However, there are alternative ways to protect innovations related to medical treatments:
1. Swiss-Type Claims (Use Claims):
While direct method of treatment claims are not allowed, Japanese law permits Swiss-type claims, which protect the use of a substance for the manufacture of a medicament for a specific therapeutic purpose. For example, instead of claiming “a method of treating cancer using ADCs,” a patent could claim “the use of ADC in the manufacture of a medicament for treating cancer.”
2. Product and Composition Claims:
You can claim the composition of the antibody-drug conjugate (ADC) itself. This would protect the ADC as a product, rather than its use in treating a disease. You can also claim the process for making the ADC or its use in a pharmaceutical composition, as long as the claim does not directly relate to a method of treatment.
3. Dosage Regimens:
Japan has allowed claims related to the dosage regimen of drugs, especially if it is new and inventive. For example, you may be able to patent a specific regimen for administering an ADC if it provides a novel therapeutic effect or improves patient outcomes.
Summary:
In Japan, method of treatment claims are not permissible, but alternatives like Swiss-type claims, product claims, or dosage regimen claims can be used to protect therapeutic innovations, including those involving antibody-drug conjugates.
Human eggs do not contain yolk proteins in the same way that bird or reptile eggs do. Here’s an explanation of the key differences:
Mammalian vs. Non-Mammalian Eggs
Non-Mammalian Eggs
Birds, reptiles, and many other non-mammalian species produce eggs with distinct yolks. These yolks are rich in proteins, lipids, vitamins, and minerals that provide nutrition to the developing embryo
In chicken eggs, for example, the yolk contains about 43% of the total egg protein and all of the egg’s fat
Human/Mammalian Eggs
Human eggs, like those of other mammals, have a fundamentally different structure:
No Distinct Yolk: Human eggs do not have a separate yolk compartment
Different Nutrient Source: Instead of relying on a yolk for nutrition, human embryos receive nutrients directly from the mother’s body through the placenta after implantation
Size Difference: Human eggs are much smaller than bird or reptile eggs, as they don’t need to store large amounts of nutrients.
Protein Content in Human Eggs
While human eggs don’t have yolk proteins per se, they do contain proteins that are crucial for early development:
Maternal Proteins: Human eggs contain various maternal proteins essential for fertilization and early embryonic development.
Cytoplasmic Components: The egg cytoplasm contains organelles and molecules necessary for initial cell divisions and embryo formation.
Evolutionary Perspective
The absence of yolk in human and other mammalian eggs is an evolutionary adaptation. Mammals have developed a more direct method of nourishing their offspring through placental connections, eliminating the need for a large, nutrient-rich yolk
In summary, while human eggs contain proteins vital for early development, they lack the specific yolk proteins found in the eggs of birds, reptiles, and other non-mammalian species.
内部細胞塊の細胞は最初はNanogとGATA6の両方の遺伝子を発現しています。それがしばらくすると、NanogかGATA6のどちらかを発現する細胞が入り混じった状態（いわゆる”salt and pepper”な状態）になります。
The salt-and-pepper pattern in mouse blastocysts is compatible with signaling beyond the nearest neighbors iScience Volume 26, Issue 11, 17 November 2023, 108106 (sciencedirect.com)
The molecular logic of Nanog-induced self-renewal in mouse embryonic stem cells Nature Communications volume 10, Article number: 1109 (2019) Published: 07 March 2019 https://www.nature.com/articles/s41467-019-09041-z
NANOG initiates epiblast fate through the coordination of pluripotency genes expression Nat Commun. 2022; 13: 3550; 2022 Jun 21. https://www.nature.com/articles/s41467-022-30858-8
NANOG helps cancer cells escape NK cell attack by downregulating ICAM1 during tumorigenesis Journal of Experimental & Clinical Cancer Research volume 38, Article number: 416 (2019) Published: 16 October 2019 https://jeccr.biomedcentral.com/articles/10.1186/s13046-019-1429-z
FGF signal-dependent segregation of primitive endoderm and epiblast in the mouse blastocyst Development (2010) 137 (5): 715–724. https://doi.org/10.1242/dev.043471 01 March 2010
https://www.sciencedirect.com/science/article/pii/S009286740600300X このレビュー論文では線毛が動く様子や蛍光ビーズが左側に流れていく様子などを示したわかりやすい動画も掲載されています。
https://www.pnas.org/doi/10.1073/pnas.1620519114
原図（A～C) Hamburger, V. 1988. The Heritage of Experimental Embryology: Hans Spemann and the Organizer. Oxford University Press, Oxford. 図引用元：Scotte Gilbert Developmental Biology. 6th edition. Axis Formation in Amphibians: The Phenomenon of the Organizer https://www.ncbi.nlm.nih.gov/books/NBK10101/
Schematic Overview of Nodal and Cripto-1 Signaling Pathways. A) Canonical Nodal signaling using Cripto-1 as a co-receptor. Nodal can also activate this pathway, albeit less efficiently, independently of Cripto-1. B) Cripto-1 Nodal-independent signaling via binding with Glypican-1 and activating src/Ras/raf/PI3K downstream signaling. C) Possible signaling of Cripto-1 through binding to beta-integrins and signaling via FAK-dependent signaling pathway.
![Proposed mechanism of Cerberus inhibition. (A) Structure of BMP9-ALK1-ACTRIIB complex [37]. The disulfide linked BMP9 homodimer (center, orange) simultaneously binds the extracellular domains of the type I Activin receptor-like kinase ALK1 (light blue) and the type II Activin receptor kinase ACTRIIB (dark blue). (B) Molecular model of Nodal-receptor interactions based on the BMP9-ALK1-ACTRIIB structure. The disulfide linked Nodal homodimer (center, orange) binds the extracellular domains of the type I Activin receptor-like kinase ALK4 (light blue) and the type II Activin receptor kinase ACTRIIB or BMPRII (dark blue), likely using canonical interaction surfaces (yellow lined circles). (C-D) Cerberus forms a stable homodimer in solution [58], binds Nodal and prevents binding of Nodal to both receptors. Thus Cerberus blocks simultaneously the ALK4 interaction surface (light blue circle) and the ACTRIIB interaction surface (dark blue circle). We propose that one Cerberus protomer could block interaction surfaces within one Nodal protomer (C) or two protomers (D). We expect the overall stoichiometry of this complex to be 2:2.](https://www.researchgate.net/profile/Washington-Mutatu/publication/271219306/figure/fig11/AS:341770715058184@1458495896759/Proposed-mechanism-of-Cerberus-inhibition-A-Structure-of-BMP9-ALK1-ACTRIIB-complex.png)
To confirm the role of Nodal antagonists in A–P patterning, we analysed mutant mice lacking Lefty1 or Cerl. Lefty1-/- (ref. 
(B,C) The PrE also expresses the DVE markers Lefty1 (B), Hex and a HexP-GFP reporter transgene(C), whereas Cer1 mRNA is below detectable levels (B). Lefty1 and Hex transcripts are clearly downregulated between E5.0 and 5.25 before they reappear together with Cer1 mRNA in the most distal VE cells at E5.5. https://journals.biologists.com/dev/article/133/13/2497/52434/Nodal-specifies-embryonic-visceral-endoderm-and
https://journals.biologists.com/dev/article/122/10/3275/38985/A-Xenopus-nodal-related-gene-that-acts-in-synergy
Mature Nodal binds to the Activin receptors I and II and the co-receptor Cripto/Criptic and phosphorilates Smad2 /3. https://en.wikipedia.org/wiki/Nodal_signaling_pathway80421-7/asset/739823c5-6901-4ee1-b007-33aa46b7fe6b/main.assets/gr2_lrg.jpg)
(f) Animal pole view of stage 10.5 gastrula shows that cerberus expression is detected in a wider domain of the deep endoderm than is XHex (b). 背景より In Xenopus, the putative head inducer cerberus is expressed initially in deep endodermal cells adjacent to the involuting tissues of Spemann’s organiser [7]. Is this tissue the equivalent of the anterior visceral endoderm in the early mouse and rabbit embryo? Here, we have addressed this question by analysing the expression and function of XHex, the Xenopus cognate of murine Hex (also known as Prh) [8,9].
OTX2、HHEX、CER1、LEFTY1、および DKK1 は、マウス胚の遠位内臓内胚葉 (DVE) で発現します。
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Front Cell Dev Biol. 2024 Apr 22;12:1386739. doi: 10.3389/fcell.2024.1386739 A comprehensive review: synergizing stem cell and embryonic development knowledge in mouse and human integrated stem cell-based embryo models https://pmc.ncbi.nlm.nih.gov/articles/PMC11074781/
https://pmc.ncbi.nlm.nih.gov/articles/PMC7616279/
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