Differential expression of SOX9 in gonads of the sea turtle Lepidochelys olivacea at male‐ or female‐promoting temperatures

Abstract

In mouse and chick embryos, the SOX9 gene is down-regulated in genetic females whereas in genetic males it remains in the Sertoli cells. We studied the distribution of SOX9 protein in developing genital ridges of embryos of the sea turtle Lepidochelys olivacea incubated at male- or female-promoting temperatures, using the antibody for detection. At stages 22-24, cells in medullary cords show SOX9 positive nuclei, while coelomic epithelial cells appear negative. At stage 25 however, most medullary cells are SOX9 negative and at the female-promoting temperature, and from stage 26 onwards, SOX9 protein is not detected. At the male-promoting temperature, medullary cords remain SOX9-positive at all stages. These results suggest that SOX9 is up-regulated in Sertoli cells irrespective of primary sex-determining switch. Sex is irreversibly determined at stage 24 or 26 at the male- or female-promoting temperature, respectively (Merchant-Larios et al.,'97). The present results suggest that there is a correlation between SOX9 expression and sex determination in the olive ridley. At the male-promoting temperature, Sertoli cells expressing SOX9 become committed at stage 24 and male sex is determined, whereas at the female-promoting temperature, SOX9 is down-regulated at stage 26 and female sex is determined. J. Exp. Zool. 284:705-710, 1999.

Isolation of sox9 duplicates in catfish: localization, differential expression pattern during gonadal development and recrudescence, and hCG-induced up-regulation of sox9 in testicular slices

“…However, Sox9 overexpression in the genital ridges resulted in normal male development in transgenic mice lacking Sry (Bishop et al 2000, Qin & Bishop 2005. In mammals, birds, and turtles, expression of sox9 is up-regulated in the developing male genital ridges during testicular differentiation (Kent et al 1996, Morais da Silva et al 1996, Moreno-Mendoza et al 1999. In mice, ectopic expression of Sox9 in XX gonads resulted in the formation of testis (Vidal et al 2001).…”

“…To date, the sox9 gene has been identified in several vertebrate species including mammals (Foster et al 1994, Wagner et al 1994, Kent et al 1996, birds (Morais da Silva et al 1996), reptiles (Moreno-Mendoza et al 1999, Western et al 1999, Choudhary et al 2000, amphibians (Takase et al 2000), and fishes (Takamatsu et al 1997, Chiang et al 2001, Yokoi et al 2002. Two different forms of sox9 genes have been identified in teleosts like zebrafish, rice field eel, fugu, and medaka (Chiang et al 2001, Zhou et al 2003, Koopman et al 2004, Klü ver et al 2005.…”

Expression of Sox9, Mis, and Dmrt1 in the gonad of a species with temperature‐dependent sex determination

“…In the American alligator, Alligator mississippiensis, dimorphic expression of Mis occurs in the middle of the TSP, preceding the onset of testis-specific Sox9 (Western et al, 1999). Similarly, expression of Sox9 does not become testis-specific until the end of the TSP in both the leopard gecko and the Olive Ridley sea turtle, Lepidochelys olivacea (Moreno-Mendoza et al, 1999;Valleley et al, 2001), although Mis has not yet been characterized in these species. In the red-eared slider turtle, Mis expression has also been shown to be male-specific by the middle of the TSP (Takada et al, 2004).…”

SUHU INKUBASI MEMPENGARUHI LEVEL EKSPRESI SOX9 PADA TAHAP AWAL PERKEMBANGAN GONAD EMBRIO Chelonia mydas (PENYU HIJAU)

“…Pada spesies TSD lain seperti Eublepharis macularius dan Lepidochelys olivaceae perbedaan level ekspresi Sox9 pada suhu inkubasi yang berbeda tidak terlihat hingga TSP akhir [11]. Pada Trachemys scripta, level ekspresi AMH tampak jelas lebih tinggi pada suhu maskulinisasi pada periode TSP tengah [12], meskipun [13] menemukan perbedaan tersebut terlihat justru setelah TSP berlalu.…”