High Sequence Variations in Mitochondrial DNA Control Region among Worldwide Populations of Flathead MulletMugil cephalus

Brian Wade Jamandre,Jean-Dominique Durand,Wann-Nian Tzeng

doi:10.1155/2014/564105

Abstract

The sequence and structure of the complete mtDNA control region (CR) ofM. cephalusfrom African, Pacific, and Atlantic populations are presented in this study to assess its usefulness in phylogeographic studies of this species. The mtDNA CR sequence variations amongM. cephaluspopulations largely exceeded intraspecific polymorphisms that are generally observed in other vertebrates. The length of CR sequence varied amongM. cephaluspopulations due to the presence of indels and variable number of tandem repeats at the3′hypervariable domain. The high evolutionary rate of the CR in this species probably originated from these mutations. However, no excessive homoplasic mutations were noticed. Finally, the star shaped tree inferred from the CR polymorphism stresses a rapid radiation worldwide, in this species. The CR still appears as a good marker for phylogeographic investigations and additional worldwide samples are warranted to further investigate the genetic structure and evolution inM. cephalus.

Highlights

The advent of generation sequencing started an era of discovery for a wide array of genetic markers for population genetics, phylogeny, and so forth
We have only scratched the surface on the analyses of these new markers and most researchers still resort to using the mitochondrial DNA for population and biodiversity studies
The nonrecombining nature due to maternal inheritance and fast evolution rate compared to the nuclear genome [1] makes mitochondrial DNA (mtDNA) a popular marker for studying vertebrate population genetics [2,3,4]

Summary

Introduction

The advent of generation sequencing started an era of discovery for a wide array of genetic markers for population genetics, phylogeny, and so forth. The nonrecombining nature due to maternal inheritance and fast evolution rate compared to the nuclear genome [1] makes mtDNA a popular marker for studying vertebrate population genetics [2,3,4]. The cytochrome b (cyto b) and cytochrome oxidase I (COI) present the highest evolutionary rates; the noncoding region of the mitochondrial genome (i.e., the control region (CR)) evolves 2–5 times faster [6]. Because of this exceptionally high mutation rate characteristic, the CR was quickly considered of great utility for addressing intraspecific evolutionary questions [7, 8]

Methods

Results

Conclusion