| This study takes Gadus macrocephalus which catched in the yellow sea as anexperimental fish. The method of histology is applied to identify the developmentalstage of gonad, the method of radiate immuno assay (RIA) is used to examine thegonad steroids level,the method of immunohistochemistry is used to locate theEstrogen receptor(ER) and Androgen receptor(AR) in the gonad. The results are asfollows:1. Histological study on the development in the gonad of GadusmacrocephalusOocyte experience oogonia,primary oocytes and secondary oocyte threedevelopmental stages.Ovarian development is divided into six phases. Sperm cellundergo spermatogonia, primary spermatocytes, secondary spermatocytes, spermatidsand sperm. Testicular development is divided into six phases too. The histologicalstaining techniques shows that spermary of Gadus macrocephalus is lobular type, andthe type of ovary development is Synchronization. When late January to February,ovary reaches mature, testis is filled with sperm, and the GSI become maximum, thestage of gonad turn to V. In Match, after ovulation and ejaculation, the GSI decreasegradually, gonad develop into the next cycle. With the gonad development, the HSIdid not show the similar trend with GSI, it has remained steady in the early, andsharply declines after ovulation. 2. Studies on the cycle changes of sex steroid hormone levels inGadusmacrocephalusExtract the gonadal tissue. The method of125I labeled radioimmuneassay(RIA) isapplied to exam the changes of extract testosterone(T),17β-Estradiol(E2) levelsduring the reproductive cycle. In the female, E2levels during the development of theovaries with gradually increased, and then decreased, groups appeared significantlydifferent（P＜0.05）. When the ovaries in stage IV and V, E2levels peaked and thereare significant differences with the other stages（P＜0.05）.In stage VI, E2levels dropdown into the next reproductive cycle. Ovary T level presented in three stages,reaching the lowest value in stage Ⅱ, followed by a significant increase（P＜0.05）,when in stage V, the T level reaches a peak and having a significant difference.E2levels in male testes changes largely, it is lower in stage Ⅱ,increases significantlyin stage Ⅲ（P＜0.05）,and become maximum in late stage IV and V. When in stage IV,it decrease to the stage Ⅱlevel. The T level in testes also shows three stages, the lowlevel in stage Ⅱ,the medium level in stage Ⅲ and IV, and the significant high levelin late stage IV and V（P＜0.05）.3. Immunohistochemical study of ER and AR on the gonad of GadusmacrocephalusThis part use immunohistochemical SABC method to study the location of ERand AR in gonad tissue. ER-α was expressed in every stage of testis and ovariandevelopment, spermatogenic cysts wall show strong immunopositive reaction, ER-α islocated in the non-germinal cells (Leydig and Sertoli cell).In the female, whenoocytes in stage III, IV and V, the ER-α was found. Follicular membrane and nucleusshow strong immunopositive reaction to ER-α. But the gonad tissue show almostly noimmunopositive reaction to ER-β.The testis tissue in every stage show immunopositive reaction to AR, the mainpart is the non-germinal cells, they show strong positive reaction. When testis in stageⅢ,the Primary spermatocytes show medium reaction;in stage V, the nucleus of sperm shows some reaction. In the female, immunopositive reaction to AR was found inoocytes in stageⅡ,III,IV. Follicular cells show strong immunopositive reaction to AR.The cytoplasm of oocytes shows positive reaction to AR, when oocytes in stage II,andthe nucleus show almostly no reaction. The nucleoplasm shows positive reactionwhen oocytes in stage III and IV, but the Nucleolus shows no reaction. Oocytesradiology film shows medium immunopositive reaction to AR when in stage V. |
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