Orvis Grant D, Behringer Richard R
Program in Genes and Development, The University of Texas, Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA.
Dev Biol. 2007 Jun 15;306(2):493-504. doi: 10.1016/j.ydbio.2007.03.027. Epub 2007 Mar 27.
Regardless of their sex chromosome karyotype, amniotes develop two pairs of genital ducts, the Wolffian and Müllerian ducts. As the Müllerian duct forms, its growing tip is intimately associated with the Wolffian duct as it elongates to the urogenital sinus. Previous studies have shown that the presence of the Wolffian duct is required for the development and maintenance of the Müllerian duct. The Müllerian duct is known to form by invagination of the coelomic epithelium, but the mechanism for its elongation to the urogenital sinus remains to be defined. Using genetic fate mapping, we demonstrate that the Wolffian duct does not contribute cells to the Müllerian duct. Experimental embryological manipulations and molecular studies show that precursor cells at the caudal tip of the Müllerian duct proliferate to deposit a cord of cells along the length of the urogenital ridge. Furthermore, immunohistochemical analysis reveals that the cells of the developing Müllerian duct are mesoepithelial when deposited, and subsequently differentiate into an epithelial tube and eventually the female reproductive tract. Our studies define cellular and molecular mechanisms for Müllerian duct formation.
无论其性染色体核型如何，羊膜动物都会发育出两对生殖管道，即沃尔夫管和缪勒管。随着缪勒管的形成，其生长尖端在向尿生殖窦延伸时与沃尔夫管紧密相连。先前的研究表明，沃尔夫管的存在是缪勒管发育和维持所必需的。已知缪勒管是由体腔上皮内陷形成的，但其向尿生殖窦延伸的机制仍有待确定。通过基因命运图谱分析，我们证明沃尔夫管不会向缪勒管贡献细胞。实验胚胎学操作和分子研究表明，缪勒管尾端的前体细胞增殖，沿着尿生殖嵴的长度沉积一条细胞索。此外，免疫组织化学分析显示，发育中的缪勒管细胞在沉积时是中上皮细胞，随后分化为上皮管，最终形成雌性生殖道。我们的研究确定了缪勒管形成的细胞和分子机制。
