Molecular Phylogeography and Population Genetic Structure of an Endangered Species Pachyhynobius shangchengensis (hynobiid Salamander) in a Fragmented Habitat of Southeastern China

Abstract

The salamander Pachyhynobius shangchengensis (Hynobiidae) is a vulnerable species restricted to a patchy distribution associated with small mountain streams surrounded by forested slopes in the Mount Dabieshan region in southeastern China. However, molecular phylogeography and population genetic structure of P. shangchengensis remain poorly investigated. In this study, we explored the genetic structure and phylogeography of P. shangchengensis based on partial sequences of the mitochondrial DNA (mtDNA) cytochrome b and cytochrome c oxidase subunit I genes. Fifty-one haplotypes and four clades were found among 93 samples. Phylogenetic analyses revealed four deeply divergent and reciprocally monophyletic mtDNA lineages that approximately correspond to four geographic regions separated by complicated topography and long distances. The distinct geographic distributions of all lineages and the estimated divergence time suggest spatial and temporal separation coinciding with climatic changes during the Pleistocene. Analysis of molecular variance indicated that most of the observed genetic variation occurred among the four groups, implying long-term interruption of gene flow, and the possible separation of P. shangchengensis into four management units for conservation.

Identification of conservation units of the hynobiid salamander Pachyhynobius shangchengensis

“…Significant geographical partitioning is one of the most important criteria for ESU identification (Dizon et al, 1992). Four ESUs were identified, which is consistent with the results of Zhao et al (2013) but differs from the results of Pan et al (2014). There are at least four criteria for the identification of ESUs: significant genetic differentiation, geographical isolation, ecological traits, and morphometric data (De Guia and Saitoh, 2007), and the absence of any of these criteria will yield only partial ESUs (De Guia and Saitoh, 2007).…”

“…It is a rare and endangered species (Wu et al, 1994;Cai, 2001;Fei et al, 2006;Wang et al, 2009;Xiong et al, 2009;Duan et al, 2010). Based on phylogenetic studies, four MUs (Zhao et al, 2013) or three ESUs (Pan et al, 2014) have been identified. The four MUs recognized by Zhao et al (2013) are actually four ESUs, since they were identified based on the criterion of reciprocal monophyly.…”

“…Based on phylogenetic studies, four MUs (Zhao et al, 2013) or three ESUs (Pan et al, 2014) have been identified. The four MUs recognized by Zhao et al (2013) are actually four ESUs, since they were identified based on the criterion of reciprocal monophyly. The genetic criterion for the identification of an ESU is that "ESUs should be reciprocally monophyletic for mtDNA alleles, and exhibit significant divergence of allele frequencies at nuclear loci" (Moritz, 1994).…”

“…All of the populations were geographically separated from each other (Figure 1). The present study aimed to identify the ESUs of P. shangchengensis using methods that can detect cryptic species, and compare the results with the reported descriptions of the ESUs for this species (Zhao et al, 2013;Pan et al, 2014). Mitochondrial cytochrome b (mtDNAcyt b) and cytochrome c oxidase subunit I (mtDNA COI) were used as molecular markers in the analysis.…”

Characterisation of the relationship between Spirometra erinaceieuropaei and Diphyllobothrium species using complete cytb and cox1 genes

“…As a result of their high and rapid mutational rates, cytb and cox1 genes have generally been accepted as dependable representatives for assessing the genetic variations and phylogenetic relationships in populations (Michelet et al, 2010;Zhao et al, 2013). Using complete sequences of cytb and cox1 genes, this study described analyses in S. erinaceieuropaei populations obtained from 11 collection sites in three eastern Chinese provinces.…”