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Sex cords
Structures that develop from the genital ridges that further differentiate based on an embryo's sex / From Wikipedia, the free encyclopedia
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]
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