Disruption of doubly uniparental inheritance of mitochondrial DNA associated with hybridization area of European Mytilus edulis and Mytilus trossulus in Norway

Beata Śmietanka,Artur Burzyński

doi:10.1007/s00227-017-3235-5

Beata Śmietanka, Artur Burzyński

Open Access

https://doi.org/10.1007/s00227-017-3235-5

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Journal: Marine biology	Publication Date: Oct 6, 2017
Citations: 23	License type: open-access

Affiliation: Institute of Oceanology, Polish Academy of Sciences

Abstract

Doubly uniparental inheritance of mitochondria (DUI) is best known in the blue mussel Mytilus. Under this model, two types of mitochondrial DNA exist: female type (F), transmitted from females to offspring of both genders, and male type (M), transmitted exclusively from males to sons. The mitogenomes are usually highly divergent, but an occasional replacement of a typical M genome by a particular F genome has been postulated to explain reduction of this divergence. Disruption of the DUI model has been reported in hybridization areas. Here, we present a new case of DUI disruption in a hybrid M. trossulus/M. edulis population from the North Sea (Norway). No M haplotypes derived from M. trossulus were identified in this population. Typical M haplotypes derived from M. edulis (ME) were rare. Two F-type haplogroups were found: one derived from M. edulis (FE) and the second derived from M. trossulus (FT). Many haplotypes from the FT group were recombinants, with the male CR sequence coming from the M. trossulus genome (FT1 haplogroup) in contrast to M. edulis CR as in the Baltic. FT1 haplotypes were abundant in the studied population, including homoplasmic females. However, males significantly more often carried these haplotypes; therefore, male heteroplasmy involved the original FE and recombinant FT, indicating that the FT genome undergoes masculinization. Structural similarity of FT1 CR with previously reported, masculinized Baltic haplotypes, which were derived from FE/ME recombination, provides further evidence that CR M–F recombination is a prerequisite for masculinization, also in the context of native M. trossulus mtDNA.

Highlights

Blue mussels of the Mytilus edulis species complex, M. edulis, M. galloprovincialis and M. trossulus, are widely distributed in boreal and temperate waters in the Southern and Northern hemispheres (Hilbish et al 2000; Gerard et al 2008)
The from M. edulis (FE) and ME networks (Fig. 1a, c) showed spread of Norwegian sequences among other European haplotypes, except for one ME singlet which was more similar to North American M haplotypes of M. edulis described by Breton et al (2006)
In the from M. trossulus (FT) network (Fig. 1b), the Norwegian sequences formed two haplogroups separated by one mutational step only, with no haplotypes shared with Pacific populations

Summary

Introduction

Blue mussels of the Mytilus edulis species complex, M. edulis, M. galloprovincialis and M. trossulus, are widely distributed in boreal and temperate waters in the Southern and Northern hemispheres (Hilbish et al 2000; Gerard et al 2008). The three species hybridize in the areas of sympatry, providing a unique model to study complex patterns of genetic introgression (Gosling 1992; Riginos and Cunningham 2005). Hybridization with M. edulis inhabiting these areas is far less documented; it is clear that, contrary to the Baltic Sea, at least Scottish M. trossulus did not lose its mitochondrial DNA (Zbawicka et al 2010). In contrast to most animal species, where mitochondria are maternally inherited, Mytilus mussels have an unusual system of

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Conclusion