|Abstract: ||本研究目的在於探討類胰島素生長因子（insulin-like growth factors）及其受體（receptors）在黑鯛（Acanthopagrus schlegeli）生殖腺分化及發育過程的基因表現。 0+黑鯛生殖腺中，igf-1r、igf-2和igf-2r在150天有顯著上升，igf-1和insr則在60天有較高的表現；經Estradiol（E2）處理後，igf-1、igf-1r和igf-2處理組皆低於控制組表現，igf-2r和insr處理組則高於控制組；而經1,4,6-androstatriene-3,17-dione（ATD）處理後，igf-1、igf-1r、igf-2和igf-2r處理組皆低於控制組表現，insr處理組則與控制組沒有顯著差異；因此經E2處理後抑制igf-1、igf-1r、igf-2以及ATD處理後抑制igf-1、igf-1r、igf-2和igf-2r在0+黑鯛生殖腺的基因表現。1+黑鯛igf-1、igf-1r和igf-2在精巢表現量皆高於卵巢，igf-2r和insr在精巢與卵巢則沒有顯著差異；igf-1、igf-1r表現量在進入繁殖季前（7～9月）的精巢有顯著上升，而igf-2表現量在繁殖季前（10月）的精巢有顯著上升。2+黑鯛精巢切除後，卵巢的igf-1在非繁殖季（9月）以及繁殖季（1月）有顯著上升，而igf-1r、igf-2、igf-2r和insr則在繁殖季前（11月）有顯著上升。在RNA in situ hybridization染色實驗，180天黑鯛稚魚生殖腺中，igf-2主要表現位置於卵巢腔周圍的卵巢組織；1+黑鯛8月的生殖腺中，insr主要表現於卵巢組織的初級卵母細胞。在免疫染色實驗，150天黑鯛稚魚生殖腺中，Insr主要表現在germ cell以及在經E2處理的1+黑鯛10月生殖腺中，Insr主要表現在精巢的spermatogonia和卵巢的oogonia；1+黑鯛12月生殖腺中，Igf-1r主要表現在具功能性精巢的spermatogonia以及退化性卵巢的primary oocyte周圍的follicle cells，並且Igf-1r表現在進入卵黃堆積時期卵細胞周圍的follicle cells。 本研究結果顯示，igf-1、igf-1r和igf-2因黑鯛生殖腺不同時期的發育，在精巢與卵巢的表現量會有不同的變化；而分別經E2和ATD處理後，0+黑鯛生殖腺igf-1、igf-1r和igf-2表現下降，因而可能進一步抑制生殖腺分化和發育。推論igf-1、igf-1r、igf-2、igf-2r和insr對促進黑鯛生殖腺分化及發育扮演重要角色。|
The objective of this study was to investigate the gene expression of insulin-like growth factor (IGFs) and their receptors during the sex differentiation and development of the black porgy (Acanthopagrus schlegeli). Igf-1r, igf-2 and igf-2r were significantly increased at 150 dah, and the expression levels of igf-1 and insr were higher at the 60 dah than the other stages in the gonad of 0+ black porgy (BP). Estradiol (E2) reduced the expression levels of igf-1, igf -1r and igf-2. However, E2 increased the expression levels of igf-2r and insr. 1,4,6-androstatriene-3,17-dione (ATD，aromatase inhibitor) reduced the expression levels of igf-1, igf-1r, igf-2 and igf-2r. However, there was no significant effect of ATD on the expression of insr. The expression levels of igf-1, igf-1r and igf-2 in testis were higher than ovary of 1+ BP, and igf-2r and insr showed no significant differences in testis and ovary. Igf-1 and igf-1r were significantly increased in testis during the pre-spawning season (from July to September), and igf-2 was significantly increased in testis in October. The expression of igf-1 was significantly increased in testis-excised gonad of 2+ BP in September and January, and the expression levels of igf-1r, igf-2, igf-2r and insr were significantly increased in November. By RNA in situ hybridization, igf-2 was expressed mainly in oogonia and primary oocyte in the gonad of 180 dah juvenile BP, and insr was expressed in the primary oocyte of the ovary of 1+BP. By immunohistochemical stainning, Insr was expressed mainly in germ cells of 150 dah juvenile BP and also in spermatogonia and oogonia of 1+BP gonad at pre-spawning season, Igf-1r was expressed in the follicle cells and spermatogonia of 1+BP at the pre-spawning season and also in the follicle cells of 3+BP at the spawning season. The results showed that the expressions of igf-1, igf-1r and igf-2 at various developmental stages were significantly different between testis and ovary. E2 and ATD reduced the expression of igf-1, igf-1r and igf-2 in the gonad of 0+ BP, suggesting that E2 and ATD might inhibit the gonadal differentiation and later development. Therefore, igf-1, igf-1r, igf-2,igf-2r and insr might play important roles in the gonadal development and differentiation of BP.