%0 Journal Article
%T High Sequence Variations in Mitochondrial DNA Control Region among Worldwide Populations of Flathead Mullet Mugil cephalus
%A Brian Wade Jamandre
%A Jean-Dominique Durand
%A Wann-Nian Tzeng
%J International Journal of Zoology
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/564105
%X The sequence and structure of the complete mtDNA control region (CR) of M. cephalus from 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 among M. cephalus populations largely exceeded intraspecific polymorphisms that are generally observed in other vertebrates. The length of CR sequence varied among M. cephalus populations due to the presence of indels and variable number of tandem repeats at the 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 in M. cephalus. 1. Introduction The advent of next generation sequencing started an era of discovery for a wide array of genetic markers for population genetics, phylogeny, and so forth. However, we have only scratched the surface on the analyses of these new markers and most researchers still resort to using the mitochondrial DNA (mtDNA) for population and biodiversity studies. Furthermore, 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¨C4]. Within the mitochondrial genome, evolutionary rates are highly variable among genes. For example, in salamanders, nucleotide substitution rates may range from 0.1 to 1 substitution/site/million years (MY) [5]. Among the coding genes, the cytochrome b (cyto b) and cytochrome oxidase I (COI) present the highest evolutionary rates; however, the noncoding region of the mitochondrial genome (i.e., the control region (CR)) evolves 2¨C5 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]. In Teleostei, the CR is located between and . Structurally, the CR is composed of a central conserved domain flanked by two highly variable (left and right) domains (Figure 1). In these large domains, several short (approximately <30£¿bp) but conserved sequenced blocks (CSBs) have been described and varied in occurrence between taxa [2]. In the central conserved domain, the CSB-D is
%U http://www.hindawi.com/journals/ijz/2014/564105/