澎湖地區麗紋石龍子族群遺傳結構研究

study on the population genetic structure of five-shipped blue-tailed skink (eumeces elegans) in penghu

吳孟修

指導教授 ： 呂光洋

國立臺灣師範大學/理學院/生物學系/碩士(2000年)

摘要

摘要
本研究利用同功酵素（isozyme）電泳技術分析澎湖地區23個島嶼25個麗紋石龍子（Eumeces elegans）族群的遺傳結構，共241隻個體；另外在馬祖、台灣亦分別取2及6個族群做比較。總計33個族群310隻個體。
本研究共判讀了14種同功酵素，包括20個基因座（locus）52個等位基因（allele）。全部33族群（包含澎湖）及澎湖25族群的平均等位基因數（A值：mean no. of alleles per locus）分別為2.6及2.3個，多型性基因座比例（P值：precentage of loci polymorphic）分別為50％及45％，平均觀測異型合子（Ho值：mean observed heterozygosity per locus）分別為0.091及0.096，平均理論異型合子（He值：mean expected heterozygosity per locus）分別為0.191和0.177。島嶼面積分別與A值、Ho值、基因型數目（no. of genotypes）呈正相關（P<0.001，R=0.790；P<0.05，R=0.485；P<0.05，R=0.511）；島嶼面積以10為底取對數後，與A值、P值、Ho值、He值、基因型數目皆呈正相關（P<0.001，R=0.756；P<0.01，R=0.666；P<0.001，R=0.776；P<0.05，R=0.720；P<0.05，R=0.563）。
澎湖25族群及台灣6族群的近親交配指數（FIS）分別為0.3337及0.3826，顯示族群內個體有近親交配的傾向；族群分化指數（FST）分別為0.1867及0.1598，顯示澎湖族群間的分化大於台灣族群；基因交流值（Nm）分別為1.089及1.314，顯示台灣族群間的基因交流較順暢。
本研究的33個族群間遺傳距離（genetic distance）最遠為0.279，遺傳相似度（genetic identity）最小者為0.757；由群叢分析（Neighbor-Joining）得到台灣區麗紋石龍子可依澎湖、馬祖、台灣分為3群。分群主要受到MPI-1*、MPI-2*、GPI*三個基因座的影響。全部族群之間的遺傳距離與地理距離呈正相關（P<0.001，R=0.604），但在澎湖族群之間或台灣的族群之間則否。

關鍵字

澎湖 ； 麗紋石龍子 ； 族群遺傳學 ； 同功酵素 ； 島嶼生物學 ； 島嶼面積

並列摘要

Abstract
In this study, we used electrophoretic technique to investigate the population genetic structure among 25 populations of Eumeces elegans in Penghu. Animals were collected from 23 islands of Penghu, 2 and 6 populations were collected from Marzu and Taiwan respectively for comparison. The total samples in this study are 310 individuals.
Twenty presumed gene loci resolved 52 alleles in 14 isozymes. The mean number of alleles per locus, the precentage of loci polymorphic, the mean observed and expected heterozygosity per locus of total population are A=2.6, P=50%, Ho=0.091 and He=0.191 respectively. The numbers of 25 populations in Penghu are A=2.3, P=45%, Ho=0.096 and He=0.177 respectively. The A, Ho and the number of genotypes were positively correlated with the area of islands (P<0.001, R=0.790; P<0.05, R=0.485; P<0.05, R=0.511). The A, P, Ho, He and the number of genotypes were positively correlated also with the island areas calculated depending on log10 (P<0.001, R=0.756; P<0.01, R=0.666; P<0.001, R=0.776; P<0.05, R=0.720; P<0.05, R=0.563).
The inbreeding coefficient (FIS) of Penghu and Taiwan populations is 0.3337 and 0.3826 respectively and it indicates that there is an obvious trend of intrapopulation inbreeding. The value of differentiation coefficient (FST) is 0.1867 and 0.1598 respectively and it indicates that the differentiation in Penghu is large. The mean value of gene flow (Nm) is 1.089 and 1.314 respectively and it indicates that the degree of gene flow is high.
The longest genetic distance is 0.279 and the smallest genetic identity is 0.757 among 33 populations in this study. The result from Neighbor-Joining analysis indicates that the E. elegans was differentiated into 3 groups. The 2 populations of Marzu were on the proximal branches. Six populations of Taiwan and populations of Penghu were on the other 2 groups. The differentiation influenced with MPI-1*、MPI-2*、GPI*. The genetic distance is positively correlated with geographic distance among all populations (P<0.001, R=0.604). This tendency was not observed in Penghu and Taiwan populations.

並列關鍵字

penghu ； eumeces elegans ； population genetics ； allozyme ； island geography

參考文獻

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