Sex cords are embryonic structures which eventually will give rise (differentiate) to the adult gonads (reproductive organs).[1] They are formed from the genital ridges - which will develop into the gonads - in the first 2 months of gestation (embryonic development) which depending on the sex of the embryo will give rise to male or female sex cords.[2] These epithelial cells (from the genital ridges) penetrate and invade the underlying mesenchyme to form the primitive sex cords.[3] This occurs shortly before and during the arrival of the primordial germ cells (PGCs) to the paired genital ridges.[3] If there is a Y chromosome present, testicular cords will develop via the Sry gene (on the Y chromosome): repressing the female sex cord genes and activating the male.[4][5] If there is no Y chromosome present the opposite will occur, developing ovarian cords.[6][7] Prior to giving rise to sex cords, both XX and XY embryos have Müllerian ducts and Wolffian ducts.[2] One of these structures will be repressed to induce the other to further differentiate into the external genitalia.[2]
- ^ Kanai, Yoshiakira; Kurohmaru, Masamichi; Hayashi, Yoshihiro; Nishida, Takao (1989). "Formation of male and female sex cords in gonadal development of C57BL/6 mouse". The Japanese Journal of Veterinary Science. 51 (1): 7–16. doi:10.1292/jvms1939.51.7. ISSN 0021-5295.
- ^ a b c Reyes, Alejandra P.; León, Nayla Y.; Frost, Emily R.; Harley, Vincent R. (2023). "Genetic control of typical and atypical sex development". Nature Reviews Urology. 20 (7): 434–451. doi:10.1038/s41585-023-00754-x. ISSN 1759-4812. PMID 37020056. S2CID 257984306.
- ^ a b Sadler, T.W. (2015). Langman's medical embryology (13th ed.). Philadelphia: Wolters Kluwer. ISBN 9781469897806. OCLC 885475111.
- ^ Wilhelm, Dagmar; Koopman, Peter (2006). "The makings of maleness: towards an integrated view of male sexual development". Nature Reviews Genetics. 7 (8): 620–631. doi:10.1038/nrg1903. ISSN 1471-0056. PMID 16832429. S2CID 20339526.
- ^ Gubbay, John; Collignon, Jérôme; Koopman, Peter; Capel, Blanche; Economou, Androulla; Münsterberg, Andrea; Vivian, Nigel; Goodfellow, Peter; Lovell-Badge, Robin (1990). "A gene mapping to the sex-determining region of the mouse Y chromosome is a member of a novel family of embryonically expressed genes". Nature. 346 (6281): 245–250. Bibcode:1990Natur.346..245G. doi:10.1038/346245a0. ISSN 0028-0836. PMID 2374589. S2CID 4270188.
- ^ Fouquet, J. P.; Dang, D. C. (1980). "A comparative study of the development of the fetal testis and ovary in the monkey (Macaca fascicularis)". Reproduction Nutrition Développement. 20 (5A): 1439–1459. doi:10.1051/rnd:19800804. ISSN 0181-1916. PMID 7349493.
- ^ Chassot, Anne-Amandine; Gillot, Isabelle; Chaboissier, Marie-Christine (2014). "R-spondin1, WNT4, and the CTNNB1 signaling pathway: strict control over ovarian differentiation". Reproduction. 148 (6): R97–R110. doi:10.1530/REP-14-0177. ISSN 1470-1626. PMID 25187620.