Studies On Gonad Of Histological Structure And The Expression Of Development-related Genes In Monopterus Albus Zuiew

In this paper, the gonadal histogenesis and development,the relative expression levelof the LH,Dmrt1,Cyp19a1a in the stage of female Monopter albus Zuiew, intersexualityMonopter albus Zuiew and male Monopter albus Zuiew were studied with histologicalmethods and RT-PCR technology.The result were as follows:(1) In the larval1day after hatch, a genital ridge similai in shape to dumbbell wasfound,located above the gut, Closed to the back of blood vessels,between the pronephric duct;In the larval2days after hatch,the position of genital ridge has not changed and divided intotwo symmetrical parts, primordial germ cells had migrated into genital ridge and primordialgonad formed; From the larval5days to20days after hatch,two reproductive glands ofprimordial gonad were merged and moved to the abdominal cavity;In the larval25daysafter hatch, two reproductive glands merged compietely, the initial ovarian formed.(2) The presence of primary oocytes occurred at the age of30days after hatch,it is asign of cytological differentiation of ovary. From the larval60days to150days afterhatch,the volume and number of primary oocytes were increased. in this time theprotoplasm proliferation gradually. From the larval180days to240days after hatch was thewinter period, a massive gap appeared in ovarian, two reproductive glands were sawsignificantiy. In the gonad before ovulation,the yolk accumulate gradually, the oocytematuration in the end.In part of the female Monopter albus Zuiew,the oocytes becomevestigial gradually,then the spermatocytes were present in the gonad after ovulation.but theothers still keep the gonad in female stage,the oocytes continued to develop in the nextbreeding cycle.Two reproductive glands were found significantiy in testis.(3) The expression of LH was detected begin in the genesis of gonad,runing on to thesex reversal occurred in gonad.The revative expression level of LH become to themaximum in the ovary at stage Ⅳ,but there was no expression in testis. We detected theexpression of Cyp19a1a in the ovary of stage Ⅲ.The raletive expression revel of DMRT1intsetis was significantly higher than in ovary,and it rised to a peak when sex reversaloccurred in the gonad.