農業部-水產試驗所全球資訊網農業部-水產試驗所全球資訊網

本研究應用吳郭魚遺傳連鎖圖譜 (linkage map)，以微衛星 (microsatellite) 分析二對歐利亞吳郭魚及其子代之性別決定相關之連鎖族群 (linkage group, LG)，試驗一共篩選出 6 個微衛星基因座(GM201、UNH104、GM271、GM354、UNH131及UNH168，分別位於LG1和 LG3) 進行基因型分析。結果顯示，二對歐利亞吳郭魚 (A1與A2家系) 的性別決定與GM271、GM354、UNH131及UNH168等四個基因座標誌有相關性 (p < 0.001)，推測歐利亞吳郭魚的性別決定應受到LG3所影響。進一步分析LG3與性別決定之關聯性，可確定A1與A2家系的性別決定系統為WZ-ZZ系統，此外，部分子代也發現有染色體交換的現象。根據這些結果將A2家系進行數量性狀基因座定位 (quantitative traits loci mapping)，可瞭解基因座相對位置與遺傳重組之頻度。總之，本研究方法未來可應用於其他種類吳郭魚之性別決定研究並有助於遺傳育種等改良工作。

In this study, we applied the microsatellite DNA markers and genetic linkage method to analyze the relationship between linkage groups (LG) and sex determination in two blue tilapia (Oreochromis aureus) families. The microsatellite loci (GM201 and UNH104 on LG1; GM271, GM354, UNH131 and UNH168 on LG3) were used for genotyping. The results showed that GM271, GM354, UNH131 and UNH168 were associated with sexuality (p<0.001) in two blue tilapia families (the A1 and A2 families), indicating that the sex-determining locus might be located on LG3 in local blue tilapia. Furthermore, the microsatellite markers on LG3 were closely related with the WZ-ZZ system in the A1 and A2 families. In addition, chromosome crossovers were observed in a small number of offspring. The A2 family was then subjected to quantitative traits loci mapping. In conclusion, the methods we used could be useful for analyzing the sex-determining locus in other tilapia species, and for facilitating the genetic selection and breeding of these fish.