Hrincevich A W, Foltz D W
Department of Zoology and Physiology, Louisiana State University, Baton Rouge 70803-1725, USA.
Mol Phylogenet Evol. 1996 Dec;6(3):408-15. doi: 10.1006/mpev.1996.0089.
A 551-bp region of a PCR product containing the putative mitochondrial control region and flanking sequences was analyzed for sequence variation among 19 sea stars representing 10 previously described PCR-RFLP haplotypes within a cryptic species complex (Leptasterias spp.). Most (97%) of the sequence variation was interhaplotypic rather than intrahaplotypic, which greatly reduced the utility of sequence polymorphisms in this mtDNA region as markers of intrahaplotypic population structure and gene flow. The estimated number of transition and transversion substitutions per nucleotide site, corrected for multiple hits, was 0.0364 and 0.0158, respectively. Most of the sequence variation occurred in the first half of the putative control region. Phylogenetic analysis (both maximum parsimony and maximum likelihood) revealed three well-supported clades, but the position of two PCR-RFLP haplotypes was not completely resolved. Low intraspecific mtDNA sequence divergence over large geographic distances may be a general pattern for echinoderm species.
对一个包含假定线粒体控制区及其侧翼序列的551碱基对的PCR产物区域进行了分析，以研究19只海星之间的序列变异，这些海星代表了一个隐性物种复合体（细海星属物种）中先前描述的10种PCR-RFLP单倍型。大部分（97%）的序列变异是单倍型间的而非单倍型内的，这极大地降低了该线粒体DNA区域序列多态性作为单倍型内种群结构和基因流标记的效用。经多重命中校正后，每个核苷酸位点的转换和颠换替代估计数分别为0.0364和0.0158。大部分序列变异发生在假定控制区的前半部分。系统发育分析（最大简约法和最大似然法）揭示了三个得到充分支持的分支，但两种PCR-RFLP单倍型的位置并未完全确定。在大地理距离上种内线粒体DNA序列分歧较低可能是棘皮动物物种的一个普遍模式。
