Friedman Michael, Schaffer Les
Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, USA.
Mitochondrial DNA. 2011 Feb;22(1-2):22-7. doi: 10.3109/19401736.2011.588218. Epub 2011 Jun 23.
BACKGROUND AND AIMS. With the goal of assessing population structure and geographic distribution of haplotype lineages among Lampropeltis elapsoides, we sequenced the ND4 mitochondrial DNA locus from 96 specimens of this snake across its area of distribution. MATERIALS AND METHODS. We relied heavily on formalin-fixed museum specimens to accomplish this analysis. RESULTS. The sequence alignment consisted of 491 bp of the selected gene, with 28% missing data. A simulation used to assess the effect of missing data on population genetic and phylogenetic resolution indicated increased character conflict, but with minimal loss of phylogenetic structure. CONCLUSION. This limited dataset suggests that L. elapsoides constitutes a largely unstructured population, with both widespread haplotypes and large number of private haplotypes, a moderate level of nucleotide diversity, and a low, but significant, degree of north-south population differentiation. Haplotype structure and frequency, nucleotide frequency, and values for Tajima's D and Fu's F(S) indicate a recent range or population expansion following a historic bottleneck.
背景与目的。为了评估乳蛇（Lampropeltis elapsoides）单倍型谱系的种群结构和地理分布，我们对该蛇分布区域内的96个样本的线粒体DNA细胞色素b基因（ND4）进行了测序。材料与方法。我们主要依靠保存在福尔马林中的博物馆标本完成了该分析。结果。序列比对包含所选基因的491个碱基对，有28%的数据缺失。用于评估缺失数据对种群遗传和系统发育分辨率影响的模拟分析表明，特征冲突增加，但系统发育结构的损失最小。结论。这个有限的数据集表明，乳蛇构成了一个基本上无结构的种群，既有广泛分布的单倍型，也有大量的私有单倍型，核苷酸多样性处于中等水平，南北种群分化程度较低但显著。单倍型结构和频率、核苷酸频率以及Tajima's D和Fu's F(S)值表明，在经历历史瓶颈后，最近出现了分布范围或种群扩张。
