Primordial Germ Cell Development

Notice - Mark Hill

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Introduction

Female uterus development

The male and female reproductive systems develop initially "indifferently", it is the product of the Y chromosome SRY gene that makes the "difference". Mesonephric duct (Wolffian Duct) and paramesonephric (Müllerian Duct) contribute the majority of male and female internal genital tract respectively.

The mesonephric/paramesonephric duct changes are one of the first male/female differences that occur in development, while external genitaila remain indeterminate in appearance for quite a while.

There are many different issues to consider in the development of the genital system. Importantly its sex chromosome dependence, late embryonic/fetal differential development, complex morphogenic changes, long time-course, hormonal sensitivity and hormonal influences make it a system prone to many different abnormalities.

Historic Embryology - Genital
General: 1901 Urinogenital Tract \| 1902 The Uro-Genital System \| 1904 Ovary and Testis \| 1912 Urinogenital Organ Development \| 1914 External Genitalia \| 1921 Urogenital Development \| 1921 External Genital \| 1942 Sex Cords \| 1953 Germ Cells \| Historic Embryology Papers \| Historic Disclaimer
Female: 1904 Ovary and Testis \| 1904 Hymen \| 1912 Urinogenital Organ Development \| 1914 External Genitalia \| 1914 Female \| 1921 External Genital \| 1927 Female Foetus 15 cm \| 1927 Vagina \| 1932 Postnatal Ovary
Male: 1887-88 Testis \| 1904 Ovary and Testis \| 1904 Leydig Cells \| 1906 Testis vascular \| 1909 Prostate \| 1912 Prostate \| 1914 External Genitalia \| 1915 Cowper’s and Bartholin’s Glands \| 1920 Wolffian tubules \| 1935 Prepuce \| 1935 Wolffian Duct \| 1942 Sex Cords \| 1943 Testes Descent \| Historic Embryology Papers \| Historic Disclaimer

Some Recent Findings

Dazl functions in maintenance of pluripotency and genetic and epigenetic programs of differentiation in mouse primordial germ cells in vivo and in vitro^[1] "We demonstrate that disruption of Dazl results in a post-migratory, pre-meiotic reduction in PGC number accompanied by aberrant expression of pluripotency genes and failure to erase and re-establish genomic imprints in isolated male and female PGCs, as well as subsequent defect in progression through meiosis. Moreover, the phenotypes observed in vivo were mirrored by those in vitro, with inability of isolated mutant PGCs to establish pluripotent EG (embryonic germ) cell lines and few residual Oct-4-expressing cells remaining after somatic differentiation of mESCs carrying a Dazl null mutation. Finally, we observed that even within undifferentiated mESCs, a nascent germ cell subpopulation exists that was effectively eliminated with ablation of Dazl."

Textbooks

Human Embryology (2nd ed.) Larson Chapter 10 p261-306
The Developing Human: Clinically Oriented Embryology (6th ed.) Moore and Persaud Chapter 13 p303-346
Before We Are Born (5th ed.) Moore and Persaud Chapter 14 p289-326
Essentials of Human Embryology, Larson Chapter 10 p173-205
Human Embryology, Fitzgerald and Fitzgerald Chapter 21-22 p134-152
Developmental Biology (6th ed.) Gilbert Chapter 14 Intermediate Mesoderm