研究生(外文):Yi-Cheng Tseng 論文名稱:透過全基因組核酸多態型資料研究台灣南部埃及斑蚊在小尺度的族群結構 論文名稱(外文):Fine-scale population structure of Aedes aegypti in southern Taiwan inferred by genome-wide SNPs 指導教授:王弘毅;黃旌集 指導教授(外文):Hurng-Yi Wang;Chin-Gi Huang 學位類別:碩士 校院名稱:國立臺灣大學 系所名稱:生態學與演化生物學研究所 論文出版年:2023 語文別:中文 論文頁數:59 論文摘要
埃及斑蚊(Aedes aegypti)是登革熱(Dengue fever)等蚊媒傳染病(Mosquito-Borne Diseases)主要傳播的媒介。瞭解埃及斑蚊的分布及散播有益於控制病媒蚊的散播。本研究採集了台南市、高雄市和屏東縣等地168個具有明確座標的埃及斑蚊樣本，利用雙切限制酶片段DNA定序法(ddRAD-seq)生成的核酸多態性資料，研究台灣南部埃及斑蚊的族群結構和親屬關係。結果顯示，各行政區埃及斑蚊的有效族群量約為兩萬，族群間的遺傳分化程度低。親屬關係分析顯示，表親關係(Loiselle's k: 0.093875 > k > 0.046875)的蚊蟲最遠可相距42.8公里，遠超文獻記錄的自然情況下斑蚊可移動的距離。
另外在小尺度地理範圍(約4平方公里)內，不僅在不同行政區間的基因距離(Rousset’s a scores)有顯著差異，且地理距離與基因距離也呈現顯著的正相關。然而，在橫跨三個縣市的大尺度地理範圍內，本研究預期基因距離與地理距離間的關係可能因為人為活動的影響，而無顯著相關，但結果依然呈現顯著的正相關。但因有相距42.8公里的表親關係埃及斑蚊存在，表示人為的交通因素仍然可能影響埃及斑蚊的擴散能力，只是無法從基因距離與地理距離的顯著與否中得知。
論文外文摘要
This study aims to understand how Aedes aegypti spreads and different populations are interlinked. 168 samples were chosen from a dengue vector monitoring network in rural areas of southwestern Taiwan, in combination with the current urban ovitrap system, both of which were established by our team. We used single-nucleotide polymorphisms (SNPs) obtained from double-digest restriction-site associated DNA sequencing (ddRAD-seq) to study the population structure and phylogenetic relationships of Ae. aegypti in southern Taiwan. The results indicated that the effective population size of the Ae. aegypti in each administrative district is approximately 20,000, with low genetic differentiation between districts.
For understanding the dispersal range of Ae. aegypti, I used Spatial Pattern Analysis of Genetic Diversity (SPAGeDi) to calculate the kinship relationship. Then a pairwise relatedness across geographic distance plot was produced with the coordinates of collected samples. The results show that although the separation distances were up to 42.8 km, the pairwise relatedness of first cousin (Loiselle’s k: 0.093875 > k > 0.046875) still can be found.
Additionally, within a small geographical scale (approximately 4 square kilometers), not only is there a significant difference in genetic distance (Rousset’s a scores) between different administrative districts, there is also a significant positive correlation between geographical distance and genetic distance. However, across a large geographical scale spanning across three counties, contrary to our expectation that there may be no significant correlation between genetic and geographical distance due to human activities, the genetic and geographical distance show a significant positive correlation. However due to the presence of Ae. aegypti with cousin relationships as far apart as 42.8 kilometer, indicating that human transportation factors could have an effect on the dispersal ability of the Ae. aegypti.