The mesonephric duct, also known as the Wolffian duct, archinephric duct, Leydig's duct or nephric duct, is a paired organ that develops in the early stages of embryonic development in humans and other mammals. It is an important structure that plays a critical role in the formation of male reproductive organs. The term Wolffian duct is named after Caspar Friedrich Wolff, a German physiologist and embryologist who first described it in his dissertation in 1759.[1]
| Mesonephric duct | |
|---|---|
 Urogenital sinus of female human embryo of eight and a half to nine weeks old | |
| Details | |
| Carnegie stage | 11 |
| Days | 28 |
| Precursor | Intermediate mesoderm |
| Gives rise to | Vasa deferentia, seminal vesicles, epididymides, Gartner's duct |
| Identifiers | |
| Latin | ductus mesonephricus; ductus Wolffi |
| MeSH | D014928 |
| TE | duct_by_E5.6.2.0.0.0.4 E5.6.2.0.0.0.4 |
| Anatomical terminology | |
During embryonic development, the mesonephric duct form as a part of the urogenital system.[2]
Structure
editThe mesonephric duct connects the primitive kidney, the mesonephros, to the cloaca. It also serves as the primordium for male urogenital structures including the epididymides, vasa deferentia, and seminal vesicles.
Development
editThe mesonephric duct typically forms around the 3rd-4th week of pregnancy, before the paramesonephric duct (also known as the Müllerian duct).
In both males and females, the mesonephric duct develops into the trigone of urinary bladder, a part of the bladder wall, and also produces WNT9B, which is required for the elongation of the paramesonephric duct.[3]
Male
editIn a male, it develops into a system of connected organs between the efferent ducts of the testis and the prostate, namely the epididymis, the vas deferens, and the seminal vesicle. The prostate forms from the urogenital sinus and the efferent ducts form from the mesonephric tubules.
For this, it is critical that the duct is exposed to testosterone during embryogenesis. Testosterone binds to and activates androgen receptor, affecting intracellular signals and modifying the expression of numerous genes.[4]
In a mature male, the function of this system is to store and mature sperm, and provide accessory semen fluid.
Female
editIn a female, with the absence of anti-Müllerian hormone secretion by the Sertoli cells and subsequent Müllerian apoptosis, the mesonephric duct regresses, although inclusions may persist. The vestigial epoophoron arises from this duct. Also, lateral to the wall of the vagina, a Gartner's duct could develop as a remnant. Normal regression starts with the action of COUP-TFII in the Wolffian mesenchyme.[5]
The mesenchyme of the mesonephric duct is retained in female reproductive tissue after sexual differentiation. As the mesonephric duct regresses, they undergo significant chromatin remodeling and move to surround the paramesonephric duct. Cells from the Wolffian mesenchyme occur in a layer around the inner epithelium, where the Müllerian mesenchyme cells also reside. The two can be distinguished by their gene expression profile: cells derived from the Wolffian mesenchyme expresses AR, while those from the Müllerian mesenchyme expresses AMHR2. Both types of mesenchyme become smooth muscle and fibroblasts. They appear quite evenly mixed in the oviduct, but remain clearly separated the uterus, with the Wolffian mesenchyme settling in the mesometrial side.[6]
Additional images
edit_(20754316592).jpg)
Diagram of a transverse section, showing the mode of formation of the amnion in the chick
Reconstruction of a human embryo of 17 mm
Cloaca of human embryo from twenty-five to twenty-seven days old
Tail end of human embryo thirty-two to thirty-three days old
Tail end of human embryo; from eight and a half to nine weeks old
See also
editReferences
edit- ↑ synd/2845 at Whonamedit?
- ↑ Du, Hongling; Taylor, Hugh S. (2015). "Development of the Genital System". Principles of Developmental Genetics. pp. 487–504. doi:10.1016/b978-0-12-405945-0.00027-2. ISBN 978-0-12-405945-0.
- ↑ Roly, Zahida Yesmin; Backhouse, Brendan; Cutting, Andrew; Tan, Tiong Yang; Sinclair, Andrew H.; Ayers, Katie L.; Major, Andrew T.; Smith, Craig A. (May 2018). "The cell biology and molecular genetics of Müllerian duct development". WIREs Developmental Biology. 7 (3) e310. doi:10.1002/wdev.310. PMID 29350886.
- ↑ Hannema, Sabine E.; Print, Cristin G.; Charnock-Jones, D. Stephen; Coleman, Nick; Hughes, Ieuan A. (2006). "Changes in gene expression during Wolffian duct development". Hormone Research. 65 (4): 200–209. doi:10.1159/000092408. PMID 16567946. ProQuest 1233606874.
- ↑ Zhao, F; Grimm, SA; Yao, HH (2020). "Molecular Actions Underlying Wolffian Duct Regression in Sexual Differentiation of Murine Reproductive Tracts". Sexual Development. 14 (1–6): 51–59. doi:10.1159/000513878. PMC 8328876. PMID 33684916.
- ↑ Zhao, F; Grimm, SA; Jia, S; Yao, HH (September 2022). "Contribution of the Wolffian duct mesenchyme to the formation of the female reproductive tract". PNAS Nexus. 1 (4) pgac182. doi:10.1093/pnasnexus/pgac182. PMC 9523451. PMID 36204418.
External links
editFurther reading
edit- Crossen, MJ; Wilbourne, J; Fogarty, A; Zhao, F (August 2023). "Epithelial and mesenchymal fate decisions in Wolffian duct development". Trends in Endocrinology and Metabolism. 34 (8): 462–473. doi:10.1016/j.tem.2023.05.007. PMC 10524679. PMID 37330364.