Hox gene expression in the embryonic genital system of the sea turtle Lepidochelys olivacea (Eschscholt, 1829), a species with temperature-dependent sex determination.
Hox genes are conserved transcription factors which regulate embryonic morphogenesis and differentiation. For the first time, we examined the quantitative and spatial expression of two Hox 5' genes, HoxD11 and HoxA13, in the developing genital system of the olive ridley Lepidochelys olivacea, a species with temperature-dependent sex determination. Quantitative and spatial expression patterns of both genes suggest a role in the female pathway rather than the male pathway. For instance, both genes, especially HoxA13, were expressed in the undifferentiated gonad during the thermosensitive period at a female promoting temperature, and downregulated in the differentiated gonad. By contrast, expression of both genes was low in gonads incubated at a male promoting temperature and did not change significantly in the differentiated gonad. Furthermore, we found high expression levels of HoxA13 in the paramesonephric duct at the male promoting temperature but not at the female promoting temperature, suggesting a role for this Hox gene in the partial regression of the Müllerian duct in males.
Sifuentes-Romero
Itzel
I
Laboratorio de Biología Molecular, Centro de Investigación en Alimentación y Desarrollo, A.C., Avenida Sábalo-Cerritos s/n, Mazatlán, Sinaloa 82010, Mexico.
Merchant-Larios
Horacio
H
García-Gasca
Alejandra
A
D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004625:Embryo, Nonmammalian; D005260:Female; D018507:Gene Expression Regulation, Developmental; D005835:Genitalia / Q000196:embryology* / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D012689:Sequence Homology, Nucleic Acid; D012727:Sex Characteristics; D019849:Sex Determination Processes; D013696:Temperature; D014426:Turtles / Q000196:embryology* / Q000235:genetics*
D018398:Homeodomain Proteins; C099959:homeobox protein HOXA13