Phylogeographic Structure of the Formosan Wood Mouse, Apodemus semotus Thomas

臺灣森鼠（Apodemus Semotus Thomas）之地理類緣關係

許富雄(Fu-Hsiung Hsu) ； 林飛棧(Fei-Jann Lin) ； 林曜松(Yao-Sung Lin)

《Zoological Studies》 40卷2期 (2001/04) Pp. 91-102

摘要

本研究利用PCR-RFLP的方法來分析臺灣地區23個族群，271隻臺灣森鼠(Apodemus semotus Thomas)之粒線體DNA的地理類緣關係。我們利用11種不同的限制酶(restriction enzyme)來分析其粒線體DNA之CYTb-DL(約2800bp)基因片段的限制酶片段多型性(RFLP，restriction fragment length polymorphism)。結果獲得44個粒線體DNA的單倍基因型(haplotype)，各單倍基因型的序列差異介於0.20％至3.20％之間。透過類緣關係的分析，我們可以發現有四個主要的分枝群，各分枝群的序列差異介於0.86％至1.78％之間。雖然這四個分枝群的基因歧異度和地理分布頗為複雜，但仍可發現各分枝群都侷限分布在由此至南的特定地理區域中。藉由七個主要單倍基因型的地理分布及各族群UPGMA的分析，我們可以將所有的臺灣森鼠族群區分成北部及中南部山區等兩個地理族群。我們推測這可能是臺灣森鼠受到更新世冰期的影響，移往山區間的避難所，而在冰期過後各族群再度擴散至各山區而相互混合的結果。

關鍵字

地理類緣關係 ； 粒線體DNA ； 限制酶片段多型性 ； 臺灣森鼠

並列摘要

Phylogeographic structure of the Formosan wood mouse, Apodemus semotus Thomas (Muridae), was studied by the PCR-RFLP method. In total, 271 individuals collected from 23 locations throughout its distribution range in Taiwan were examined. Eleven restriction enzymes were used to assay restriction fragment length polymorphism in a 2800-bp PCR- amplified fragment of mtDNA, representing part of the cytochrome b (CYTb) and the control region (DL). In total, forty-four mtDNA haplotypes were detected. The sequence divergence between all pairs of haplotypes ranged between 0.20% and 3.20% Phylogenetic analysis revealed that the 4 primary mtDNA lineages have been separated by sequence divergences of 0.86% to 1.78%. The geographic structure of mtDNA diversity and the lineage distribution are complex, but each lineage reveals a limited geographic distribution from north to south in the Gentral Mountain Range of Taiwan. According to the geographic distribution of 7 dominant haplotypes and the locality-based UPGMA dendrogram, we resolved the northern and south-central geographical assemblages. This phylogeographic pattern of the species might have resulted from a plausible historical scenario involving isolation of its populations in several intermontane refugia, and their redispersion and introgression in postglacial periods during the Pleistocene.

並列關鍵字

Phylogeographic structure ； mtDNA ； RFLP ； Apodemus semotus