Cellular mechanisms of Müllerian duct formation in the mouse Grant D. Orvis, Richard R. Behringer Developmental Biology Volume 306, Issue 2, 15 June 2007, Pages 493-504 Developmental Biology https://www.sciencedirect.com/science/article/pii/S001216060700228X?via%3Dihub
に詳し解析があります。
In the first phase, cells of the coelomic epithelium are specified to a Müllerian duct fate through an unknown mechanism. This specification can be identified by the expression of Lim1 in cells of the coelomic epithelium (Kobayashi et al., 2004).
After specification, Wnt4expression from the mesonephros or coelomic epithelium, induces the invagination of these specified cells (Kobayashi et al., 2004, Vainio et al., 1999).
when the Wolffian duct is disrupted at a specific point in ovo, the Müllerian duct is unable to grow past that point (Gruenwald, 1937).
Primitive umbilical cord and contents. A. A 5-week embryo showing structures passing through the primitive umbilical ring. B. The primitive umbilical cord of a 10-week embryo. C. Transverse section through the structures at the level of the umbilical ring. D. Transverse section through the primitive umbilical cord showing intestinal loops protruding in the cord. (Reprinted with permission from Sadler TW. Langman’s Medical Embryology. 13th ed. Philadelphia, PA: Wolters Kluwer Health; 2015.) https://renaissance.stonybrookmedicine.edu/system/files/Umbilical%20Cord%20Disorders.pdf
definitive umbilical cord もしくは単にumbilical cord 臍帯
Diagrams showing the (A) folding of the embryo and formation of the primitive umbilical cord and (B) definitive umbilical cord.
The allantois is functionally obliterated early in development but leaves remnants that persist after birth. Here’s how it works:
Timeline of Allantois Obliteration 消滅:
Early Embryogenesis:
The allantois emerges as a small endodermal outpouching of the hindgut.
It extends into the connecting stalk (which contributes to the formation of the umbilical cord) and plays a role in early gas exchange and the development of the umbilical arteries and veins.
By the end of the first trimester, its role in development diminishes as the placenta takes over waste exchange.
Obliteration during Development:
The lumen of the allantois is obliterated during the second trimester, and it becomes a fibrous cord known as the urachus(尿膜管), which runs from the bladder to the umbilicus.
By birth, the allantois is no longer a functional structure, but its remnant persists as the median umbilical ligament (正中臍索)in postnatal life.
Postnatal Remnants:
The median umbilical ligament extends from the apex of the bladder to the umbilicus and is the fibrous remnant of the allantois.
If the obliteration of the allantois is incomplete, it can result in abnormalities like a urachal cyst, urachal sinus, or even a urachal fistula, which might require surgical correction.
The Androgen Receptor Governs the Execution, but Not Programming, of Male Sexual and Territorial Behaviors Scott A. Juntti 1 6 , Jessica Tollkuhn 3 6 , Melody V. Wu 1 , Eleanor J. Fraser 2 , Taylor Soderborg 3 7 , Stella Tan 3 8 , Shin-Ichiro Honda 5 , Nobuhiro Harada 5 , Nirao M. ShahNeuron Volume 66, Issue 2, 29 April 2010, Pages 260-272 https://www.sciencedirect.com/science/article/pii/S0896627310001959?via%3Dihub
Estrogen Masculinizes Neural Pathways and Sex-Specific BehaviorsCell Volume 139, Issue 1, 2 October 2009, Pages 61-72 Melody V. Wu 1 , Devanand S. Manoli 4 , Eleanor J. Fraser 2 , Jennifer K. Coats 1 , Jessica Tollkuhn 3 , Shin-Ichiro Honda 6 , Nobuhiro Harada 6 , Nirao M. Shah https://www.sciencedirect.com/science/article/pii/S0092867409009167?via%3Dihub
性ホルモン(アンドロゲン、エストロゲン)とストレス反応との関連性
Roles for androgens in mediating the sex differences of neuroendocrine and behavioral stress responses Biology of Sex Differences volume 11, Article number: 44 (2020) 総説 https://bsd.biomedcentral.com/articles/10.1186/s13293-020-00319-2
Gonadal primordia is observed in humans in week 5 of gestation, being under the control ofWT1, NR5A1, NR0B1, CBX1/2, LHX9, EMX2, GATA4, and SIX1/4 [15].
Studies in mice have shown that, at this moment, genes that are associated with Sertoli (testicular) (SOX9, FGF9, PGD2) or granulosa (ovarian) (WNT4, RSPO1, CTNNB1, FST) differentiation are expressed at similar levels in both the XY and XX fetus [16,17,18].