Open AccessFootprints of unconventional mitochondrial inheritance in bivalve phylogeny: Signatures of positive selection on clades with doubly uniparental inheritance
Author(s) -
Plazzi Federico,
Passamonti Marco
Publication year - 2019
Publication title -
journal of zoological systematics and evolutionary research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.769
H-Index - 50
eISSN - 1439-0469
pISSN - 0947-5745
DOI - 10.1111/jzs.12253
Subject(s) - biology , mitochondrial dna , evolutionary biology , nuclear gene , genetics , genome , clade , inheritance (genetic algorithm) , phylogenetics , phylogenetic tree , gene
The doubly uniparental inheritance ( DUI ) of some bivalve mollusks is the major exception to the common maternal inheritance of mitochondria in animals. DUI involves two mitochondrial lineages with paternal and maternal transmission routes, and it appears as a complex phenomenon requiring both nuclear and mitochondrial adaptations. DUI distribution seems to be scattered among the Bivalvia, and there are several clues for its multiple origins. In this paper, we investigate whether the incipient DUI systems had left possible selective signatures on mitochondrial genomes. Alongside the outstanding divergence of amino acid sequences, we confirmed strong purifying selection to act on mitochondrial genes. However, we found evidence that distinct episodes of intense directional pressure are associated with the origins of different DUI systems: We interpret these signals as footprints of the coevolution with the nuclear genome that ought to take place at the base of a DUI clade. Six genes ( atp6 , cox1 , cox2 , cox3 , nad4L , and nad6 ) seem to be more commonly linked to the appearance of DUI . We also identified few putative DUI ‐specific mutations, thus extending support to the hypothesis of multiple independent origins of this complex phenomenon.