Development of Sexual Gland and Influence of Temperature on Sexual Differentiation in Rana chensinensis

Under constant and alternating temperature conditions oosperms of Rana chensinensis were cultivated till the completion of metamorphosis.The study was done on the development of sexual gland during the embryo stage,the beginning and ending periods of sexual differentiation and the relationship between temperature and sexual differentiation of Rana chensinensis.The results showed:1)In the 24th period of embryo development,a genital ridge began to appear,and in the 25th period there had been a few PGCs moved to the genital ridge.PGCs together with the genital ridge developed into a sexual gland.2)In the 31st period of embryo development,the sexual gland began to differentiate;the initial differentiation stage of an ovary was easy to recognize while the differentiation of a testis was not so obvious.3)The differentiation of the ovary completed at the 37th period,while the differentiation of the testis completed after metamorphosis,and the left and the right sides of the sexual glands were the same size.4)In the 30th period of the embryo,sex differentiation began to be impressible to temperature,and lower temperature was favorable for feminization,while higher temperature was favorable for masculinization.5)In alternating temperature conditions the impressible temperature range for the sex ratio was 15-20 ℃;slow rise of temperature would increase the male ratio,while slow drop of temperature would increase the female ratio.