Data/hora: 11/06/2024 03:18:25

Biblioteca(s): 	Embrapa Pantanal.	
Data corrente: 	17/11/1997	
Data da última atualização: 	05/04/2017	
Autoria: 	SMITH, C. A.; JOSS, J. M. P.	
Título: 	Gonadal sex differentiation in Alligator mississippiensis, a species with temperature-dependent sex determination.	
Ano de publicação: 	1993	
Fonte/Imprenta: 	Cell and Tissue Research, v.273, p.149-162, 1993.	
Idioma: 	Inglês	
Conteúdo: 	Temperature of egg incubation determines sex in Alligator mississippiensis gatchlings. To define the timing and morphology of sexual differentiation, alligator gonads were examined histologically and ultrastructurally throughout embryogenesis. At the male-producing temperature (33C), the onset of testis differentiation occurred in most embryos during developmental stages 21-22, when a number of somatic cells in the medulla of the gonad became enlarged, forming presumptive Sertoli cells. Some enlarged somatic cells were also observed at the female-producing temperature (30C) during gonadogenesis, but they were less widespread than at 33C. Ovarian differentiation at 30C began slightly later, during stage 22-23, and was characterised by proliferation of germs cells in the cortex of the gonad. Testis formation in alligators may depended upon presumptive Sertoli cells differentiating prior to a critical event in embrypgenesis, such as germ cell proliferation and meiosis. If follows that ovary formation occurs if this requirement it is not met, as at lower incubation temperatures.	
Palavras-Chave: 	Crocodile; Crocodilia; Determinacao do sexo; Diferenciacao das gonadas; Gonadal differentiation; Ovary; Reptile; Temperature-dependent sex determination.	
Thesagro: 	Crocodilo; Jacaré; Ovário; Reprodução; Réptil; Temperatura.	
Thesaurus Nal: 	Alligator mississippiensis; reproduction; Sertoli cells.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Pantanal (CPAP)	
Exemplares: 	CPAP - (35111-1) - ADD - SP - PP - SP15434 -  - 15434 - DIS