水生生物学报
水生生物學報
수생생물학보
ACTA HYDROBIOLOGICA SINICA
2013年
6期
1020-1027
,共8页
李广丽%邓思平%王文达%孙晶%吴天利%师尚丽%朱春华
李廣麗%鄧思平%王文達%孫晶%吳天利%師尚麗%硃春華
리엄려%산사평%왕문체%손정%오천리%사상려%주춘화
胡子鲇%性分化%17α-甲基睾酮%17β-雌二醇%Cyp19a1b%Foxl2
鬍子鲇%性分化%17α-甲基睪酮%17β-雌二醇%Cyp19a1b%Foxl2
호자점%성분화%17α-갑기고동%17β-자이순%Cyp19a1b%Foxl2
Clarias fuscus%Sex differentiation%17α-MT%17β-E2%Cyp19a1b%Foxl2
研究采用组织学和荧光实时定量PCR方法,检测17α-甲基睾酮(17α-MT)和17β-雌二醇(17β-E2)对胡子鲇(Clarias fuscus)性腺组织学、性别比率以及性分化前后脑型芳香化酶基因(Cyp19a1b)和翼状螺旋/叉头转录因子2(Foxl2)基因表达的影响。结果表明：在出膜后2-30日龄,17α-MT (50、100和200μg/L)浸浴、17β-E2(100、200和300μg/g)投喂处理对成活率无显著影响,但中、高剂量(100和200μg/L)17α-MT显著抑制卵巢发育,促进精巢发育,卵巢腔出现时间分别推迟4d和6d,初级卵母细胞出现时间分别推迟8d和9d,而初级精母细胞出现时间则分别提前3d和5d,且雄性率分别达70%和76%,显著高于50μg/L组和对照组(P<0.05)。相反,中、高剂量17β-E2(200和300μg/g)处理使卵巢腔出现时间分别提前2d和3d,初级卵母细胞出现时间分别提前1d和3d,初级精母细胞出现时间分别推迟3d和7d,而雌性率分别达74%和78%,显著高于100μg/g组和对照组(P<0.05)。此外,在性腺分化期,17α-MT促进Cyp19a1b但抑制Foxl2的表达,而17β-E2促进Cyp19a1b和 Foxl2的表达。结果显示Cyp19a1b不是引起胡子鲇性分化的直接因素,但可能通过“下丘脑-垂体-性腺轴”对胡子鲇性分化过程产生间接影响；而 Foxl2直接参与胡子鲇的性分化,即17α-MT 和17β-E2分别通过抑制和促进Foxl2的表达来影响雌激素的生物合成,从而调控胡子鲇性分化的方向。
研究採用組織學和熒光實時定量PCR方法,檢測17α-甲基睪酮(17α-MT)和17β-雌二醇(17β-E2)對鬍子鲇(Clarias fuscus)性腺組織學、性彆比率以及性分化前後腦型芳香化酶基因(Cyp19a1b)和翼狀螺鏇/扠頭轉錄因子2(Foxl2)基因錶達的影響。結果錶明：在齣膜後2-30日齡,17α-MT (50、100和200μg/L)浸浴、17β-E2(100、200和300μg/g)投餵處理對成活率無顯著影響,但中、高劑量(100和200μg/L)17α-MT顯著抑製卵巢髮育,促進精巢髮育,卵巢腔齣現時間分彆推遲4d和6d,初級卵母細胞齣現時間分彆推遲8d和9d,而初級精母細胞齣現時間則分彆提前3d和5d,且雄性率分彆達70%和76%,顯著高于50μg/L組和對照組(P<0.05)。相反,中、高劑量17β-E2(200和300μg/g)處理使卵巢腔齣現時間分彆提前2d和3d,初級卵母細胞齣現時間分彆提前1d和3d,初級精母細胞齣現時間分彆推遲3d和7d,而雌性率分彆達74%和78%,顯著高于100μg/g組和對照組(P<0.05)。此外,在性腺分化期,17α-MT促進Cyp19a1b但抑製Foxl2的錶達,而17β-E2促進Cyp19a1b和 Foxl2的錶達。結果顯示Cyp19a1b不是引起鬍子鲇性分化的直接因素,但可能通過“下丘腦-垂體-性腺軸”對鬍子鲇性分化過程產生間接影響；而 Foxl2直接參與鬍子鲇的性分化,即17α-MT 和17β-E2分彆通過抑製和促進Foxl2的錶達來影響雌激素的生物閤成,從而調控鬍子鲇性分化的方嚮。
연구채용조직학화형광실시정량PCR방법,검측17α-갑기고동(17α-MT)화17β-자이순(17β-E2)대호자점(Clarias fuscus)성선조직학、성별비솔이급성분화전후뇌형방향화매기인(Cyp19a1b)화익상라선/차두전록인자2(Foxl2)기인표체적영향。결과표명：재출막후2-30일령,17α-MT (50、100화200μg/L)침욕、17β-E2(100、200화300μg/g)투위처리대성활솔무현저영향,단중、고제량(100화200μg/L)17α-MT현저억제란소발육,촉진정소발육,란소강출현시간분별추지4d화6d,초급란모세포출현시간분별추지8d화9d,이초급정모세포출현시간칙분별제전3d화5d,차웅성솔분별체70%화76%,현저고우50μg/L조화대조조(P<0.05)。상반,중、고제량17β-E2(200화300μg/g)처리사란소강출현시간분별제전2d화3d,초급란모세포출현시간분별제전1d화3d,초급정모세포출현시간분별추지3d화7d,이자성솔분별체74%화78%,현저고우100μg/g조화대조조(P<0.05)。차외,재성선분화기,17α-MT촉진Cyp19a1b단억제Foxl2적표체,이17β-E2촉진Cyp19a1b화 Foxl2적표체。결과현시Cyp19a1b불시인기호자점성분화적직접인소,단가능통과“하구뇌-수체-성선축”대호자점성분화과정산생간접영향；이 Foxl2직접삼여호자점적성분화,즉17α-MT 화17β-E2분별통과억제화촉진Foxl2적표체래영향자격소적생물합성,종이조공호자점성분화적방향。
Clarias fuscus, a common freshwater fish in China, was selected as our experiment material. Two-day juve-nile C. fuscus was divided into two groups. They were immersed in different doses of 17α-methyltestosterone (50, 100, and 200 μg/L 17α-MT) or fed with 17β-estradiol (100, 200, and 300 μg/g 17β-E2) for 30 days. Effects of 17α-MT and 17β-E2 on survival rate, sex ratio, gonad histology, and Foxl2 and Cyp19a1b expressions were examined by mor-phologic observation, histology and Real time fluorescent quantitative PCR during its period of sex differentiation (2-30d after hatching). The results showed that 17α-MT and 17β-E2 had no influence on survival rate but affected sex ratio and the time of gonadal differentiation. Doses of 17α-MT at 100 and 200μg/L produced more males (70%and 76%, respectively) than 50μg/L 17α-MT (54%) did (P<0.05), but no significant difference in sex ratio was observed between the 50 μg/L 17α-MT treated group and the control group (56%). In addition, the former accelerated the occurrence of primary spermocytes for three and five days, but deferred that of ovarian cavity for four and six days, and primary oo-cytes for eight and nine days, respectively. In contrast, doses of 17β-E2 at 200 and 300μg/g produced more males (74%and 78%, respectively) than the control group (P<0.05), but no significant difference in sex ratio was observed between the 100μg/g 17β-E2 treated group (66%) and the control group (56%). Dose of 17β-E2 at 200 and 300μg/g accelerated the occurrence of ovarian cavity for two and three days, and primary oocytes for one and three days, respectively, but deferred that of primary spermatocytes for three and seven days. The expressions of Foxl2 and Cyp19a1b showed that dose of 200μg/L 17α-MT increased the expression of Cyp19a1b but inhibited that of Foxl2. However, dose of 300μg/g 17β-E2 increased the expression both of Cyp19a1b and Foxl2. The results suggested that Foxl2 but not Cyp19a1b in-volved in mediating sex differentiation directly in C. fuscus, and 17α-MT inhibited but 17β-E2 promoted the expressions of Foxl2 to influence the estrogen biosynthesis, which controlled the sex differentiation. However, Cyp19a1b played an indirect role on sex differentiation by acting on the hypothalamic-pituitary-gonadal axis.
