Tho effects of the ectopic Wnt4 on chicken gonad development.

• Main Authors: Yi-Ping Wu, 吳怡頻
• Other Authors: Hsu-Chen, Cheng
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/75035888273055792392

碩士 === 國立中興大學 === 生命科學系所 === 99 === Sex determination is a special system that decides dimorphic sex characteristic development in male and female. The difference between the two sexes involves gene expression, karyotype, gonad morphology, hormone expression, psychology and social behavior. The sex determination of birds is chromosomally based, as in mammals, but the sex chromosomes are different and the mechanism of avian sex determination remains poorly understood. In the chicken and all other birds, the male carries two Z sex chromosomes, and the female carries one Z and one W sex chromosome. In the mammal’s model, the mechanism of testis formation is now comparably well understood, but understanding of the molecular pathways specifying gonadal differentiation in female is still incomplete. The differentiation of the bipotential genital ridge into a testis requires the Y-encoded gene Sry. Sox9 and Sf1 have been shown to play a role during testis differentiation as candidates. Wnt4 and DAX1 were involved in female fate determination and Wnt4 were proposed as a candidate of female sex determining genes in 1999. The later studies indicate the importance that Wnt4 be in sex determination. Because of the avian transegene technique is not mature, the function of some sex determinate genes in gonad are not complete known. We want to study the influence of Wnt4 in chicken gonad, so we try to use different methods to provide ectopic Wnt4 in chicken gonad, and to observe gonad development. Our result indicate Wnt4 can’t change male gonad morphological structure and there‘s no aromatase expression in the male gonad. We use Sox9 as a male somatic cell marker and found SOX9 still could be detected in the Sertoli and Leydig cells of the male gonad. This analysis means that Wnt4 can’t suppress SOX9 in chicken male gonad. These are suggested that the ectopic Wnt4 expression in the chicken male gonad is not sufficient to induce sex reversal.