Zoological Studies

Vol. 40 No. 2, 2001

Phylogeographic Structure of the Formosan Wood Mouse, Apodemus semotus Thomas

Fu-Hsiung Hsu1,3,*, Fei-Jann Lin2 and Yao-Sung Lin3

1Taiwan Endemic Species Research Institute, Council of Agriculture, Chichi, Nantou, Taiwan 552
2Institute of Zoology, Academia Sinica, Taipei, Taiwan 115
3Department of Zoology, National Taiwan University, Taipei, Taiwan 106

Fu-Hsiung Hsu, Fei-Jann Lin and Yao-Sung Lin (2001) 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 Central 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 re-dispersion and introgression in postgla- cial periods during the Pleistocene.

Key words: Phylogeographic structure, mtDNA, RFLP, Apodemus semotus.

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