| Summary: | 碩士 === 國立中興大學 === 生命科學系所 === 101 === In vertebrate, Hedgehog pathway regulates the development of many organs, there are three members of the HH family: Dhh,Shh and Ihh. The Dhh-null mice are sterility in male owing to absence mature sperm but fertility in female. RA induces germ cells entry of meiosis in female embryonic stage, but not until puberty in male. Our past studies showed that Shh instead of Dhh regulates the development of testis in male chicken. In mature male chicken, ectopic Hh caused synchronous spermatogenesis progression but repressed spermatogenesis by Cyclopamine. To further understand how Hh pathway regulates spermatogenesis, we elevated HH pathway activity in prepubertal testis by providing RCAS-cShh / 20(S)-Hydroxycholesterol( Hh agonist). We found ectopic activating Hh pathway did NOT change the percentage of PTCH+ and NANOG+ cells in W7 testis, but 20(S)-Hydroxycholesterol increased the percentage of PTCH+ cells in W8 testis. Ciliobrevin A decreasing the percentage of PTCH+ cells but not NANOG+ cells. In cultured embryonic ovary, activateing Hh pathway increased the number of PTCH+ germ cells; while inhibiting Hh pathway not only inhibited Ptch expression, but also reduced germ cell number. Hence, ectopic Hh activation could NOT induce precocious spermatogenesis before W8 in testis. The spermatogonia stem cell number is NOT affected by either activation or inhibition of Hh pathway in prepubertal testis. Inhibition of Hh led to fewer germ cells in embryonic ovary.
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