- 學位論文
台灣四周海域灰鰭鯛種群遺傳分化之研究
Genetic divergence of Acanthopagrus berda species complex in the surrounding waters of Taiwan
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摘要
本研究係利用同功異構酵素對台灣四周海域中灰鰭鯛(Acanthopagrus berda)族群間遺傳結構做探討。所得族群的近交係數（Fis）為0.374，而族群間分化指數(Fst)為0.410，顯示各地點間具高度分化。加入黑鯛為外群一同分析，則發現種內遺傳距離遠大於種間遺傳距離。進一步檢視，發現個體於ADH*、G6PDH*、GPI-A*、 sMDH*四個基因座上之表現，具連鎖效應（linkage effect）。灣內、外族群各以96% 的比例，固定於此四個基因座上的相異對偶基因（allele）上，且並未發現任何雜合個體，顯示兩族群間可能存在著強烈的生殖隔離。大鵬灣型灰鰭鯛(基因型ADH* -175/-175、G6PDH * 95/95、GPI-A* 110/110、sMDH* 80/80之個體)應為一隱藏種（cryptic species ）。除去大鵬灣類型個體後，從不同來源之336尾個體中篩選出3 個多型性基因座（polymorphic loci（95%）），分別為sAAT* 、GPI-B*、IDH-2* 所估算出之族群間分化指數(Fst)為0.017，顯示族群間無分化。又由卡方聯表檢測結果(Chi-square contingency table analysis)，證實所有樣本皆歸為同一族群 P = 0.227（P > 0.05），顯示各地點樣品間基因交流無障礙，可視為同一個大族群。
並列摘要
The genetic structure among the Acanthopagrus berda from surrounding waters of Taiwan is carried out by isozyme electrophoresis. The available inbreeding coefficient (Fis) of 0.374, and fixed index (Fst) of 0.410, indicate there are significant differentiation among the overall samples examined. The interpopulational genetic distance estimated was far greater than that between species, when the A. schlegeli who used as an outgroup. Genotypes of most indivuals examined were found to have a strong linkage effect with loci ADH*、 G6PDH*、 GPI-A*、 sMDH*. The above four loci were fixed differently between samples of Dapong bay and those from other localities, due to reproduction isolation. Thus the above mentioned typical Dapong sample(= A. sp.) can be considered as a valid cryptic species. With the exclusion of Acanthopagrus sp,the remaining 336 real berda from 7 localities, scored three polymorphic loci(P95) (sAAT* 、GPI-B*、IDH-2*), with a redution of fixed index(Fst) to 0.017, indicating an extremely low level of differentiation (P=0.227>0.05), among them Chi-square contigency table analysis showed the genetic structure among different samples was homogenous, suggestion that there are strong gene flow among the samples .
參考文獻
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