Retraction Note to: The complete mitochondrial genomes of two freshwater snails provide new protein-coding gene rearrangement models and phylogenetic implications

Xidong Mu,Dangen Gu,Yexin Yang,Meng Xu,Du Luo,Hongmei Song,Yi Liu,Yinchang Hu,Hui Wei

doi:10.1186/s13071-017-2287-1

Abstract

Mitochondrial (mt) genome sequences are widely used for species identification and to study the phylogenetic relationships among Gastropoda. However, to date, limited data are available as taxon sampling is narrow. In this study we sequenced the complete mt genomes of the freshwater gastropods Radix swinhoei (Lymnaeidae) and Planorbarius corneus (Planorbidae). Based on these sequences, we investigated the gene rearrangement in these two species and the relationships with respect to the ancestral gene order and assessed their phylogenetic relationships. The complete mt genomes of R. swinhoei and P. corneus were sequenced using Illumina-based paired-end sequencing and annotated by comparing the sequence information with that of related gastropod species. Putative models of mitochondrial gene rearrangements were predicted for both R. swinhoei and P. corneus, using Reishia clavigera mtDNA structure as the ancestral gene order. The phylogenetic relationships were inferred using thirteen protein sequences based on Maximum likelihood and Bayesian inference analyses. The complete circular mt genome sequences of R. swinhoei and P. corneus were 14,241 bp and 13,687 bp in length, respectively. Comparison of the gene order demonstrated complex rearrangement events in Gastropoda, both for tRNA genes and protein-coding genes. The phylogenetic analyses showed that the family Lymnaeidae was more closely related to the family Planorbidae, consistent with previous classification. Nevertheless, due to the position recovered for R. swinhoei, the family Lymnaeidae was not monophyletic. This study provides the complete mt genomes of two freshwater snails, which will aid the development of useful molecular markers for epidemiological, ecological and phylogenetic studies. Additionally, the predicted models for mt gene rearrangement might provide novel insights into mt genome evolution in gastropods.

Highlights

Retraction The authors are retracting this article [1]
The initial morphology-based identification of the snail as “Radix swinhoei” was not tested with BLAST searches and as a result we did not realise that we had characterised the mitochondrial genome of a different species
Upon re-examination of our data, we suggest that the sample “Radix swinhoei” does represent a species of Physella

Summary

Introduction

Retraction The authors are retracting this article [1]. A reader recently raised questions related to the identification of one of the snail species whose complete mitochondrial (mt) genomes have been characterised in our article, because the gene order and mt genome sequence of the sample of Radix swinhoei (family Lymnaeidae) strongly resemble those of Physella acuta (family Physidae) (GenBank JQ390525.1 and JQ390526.1) published by Nolan et al [2].

Results

Conclusion