台灣長鬃山羊族群具有顯著遺傳變異之兩個分群

Two Distinct Phylogenetic Groups of Formosan Serow(Naemorhedus swinhoei Gray) Population in Taiwan:Based on Mitochondrial D-loop Region Sequences

本研究的目的是利用粒線體DNA的序列了解台灣長鬃山羊族群的遺傳變異與地理分布的關係，在取得的25隻台灣長鬃山羊中，定出14隻粒線體DNA的D-loop完整DNA序列（1122 bp-1124 bp），並比較25隻粒線體DNA的 D-loop 5'端變異最大部分DNA序列（493 bp-495 bp），分析結果顯示這25隻山羊中有14種單套型（haplotypes），各單套型之間的遺傳變異在 0.24%至6.85%之間；利用親緣樹關係分析結果，得到比用cytochrome b序列所建立之台灣長鬃山羊親緣樹有更高可信度的相同兩群－－花蓮太魯閣群及南投-台東群，兩分群之間平均遺傳距離約為5.53%。從粒線體DNA的 D-loop的資料顯示，台灣長鬃山羊族群至少在55萬年前的亞洲大陸可能就已分群，並於晚更新世冰河時期經由陸橋分別遷徙至台灣島，且分析兩群在台灣島的地理分布結果，可能是台灣湍急陡峭的河川加上中央山脈複雜地形造成地理條件上的阻隔。 To investigate genetic variation of the Formosan serow (Naemorhedus swinhoei Gray) population ,the nucleotide sequences 1122-1124 bases) of the mitochondrial DNA D-loop region was examined for14 of 25 samples collected from Nantou, Taidong, HualienTaroko and Wulai areas of Taiwan. Fourteenhaplotypes were detected from 25 samples with a pairwise comparison of the partial sequences (493-495bases) of the D-loop region . Genetic distance divergences were estimated to be 0.24%-6.85% among the 14 haplotypes. The phylogenetic trees constructed by the sequences indicated that the Formosan serowwas separated into two highly genetically variable groups: the Nantou-Taidong group and theHualienTaroko group. The separation of the two groups was estimated to have occurred over 0.55 millionyears ago, resulting from repeated colonization from the Asia continent to Taiwan. The rivers in theCentral Mountain Range were probably a geographic barrier for allopatric differentiation of the twogroups. Our result provided an insight into the understanding of the evolutionary history, phylogeny andpopulation genetics of the Formosan serow.