The absence of canonical respiratory complex I subunits in male-type mitogenomes of three Donax species.

Bivalves are an extraordinary class of animals in which species with a doubly uniparental inheritance (DUI) of mitochondrial DNA have been described. DUI is characterized as a mitochondrial homoplasmy of females and heteroplasmy of male individuals where F-type mitogenomes are passed to the progeny with mother egg cells and divergent M-type mitogenomes are inherited with fathers sperm cells. However, in most cases only male individuals retain divergent mitogenome inherited with spermatozoa.

Confirmation of the first intronic sequence in the bivalvian mitochondrial genome of (Linnaeus, 1758).

In 2020, the first male-type mitochondrial genome from the clam was published. Apart from the unusual doubly uniparental inheritance of mtDNA, scientists observed a unique (over 4k bp long) extension in the middle of the gene. We have attempted to replicate these data by NGS DNA sequencing and explore further the expression of the long gene.

No evidence of DUI in the Mediterranean alien species Brachidontes pharaonis (P. Fisher, 1870) despite mitochondrial heteroplasmy.

Two genetically different mitochondrial haplogroups of Brachidontes pharaonis (p-distance 6.8%) have been identified in the Mediterranean Sea. This hinted at a possible presence of doubly uniparental inheritance in this species.

Semimytilus algosus: first known hermaphroditic mussel with doubly uniparental inheritance of mitochondrial DNA.

Doubly uniparental inheritance (DUI) of mitochondrial DNA is a rare phenomenon occurring in some freshwater and marine bivalves and is usually characterized by the mitochondrial heteroplasmy of male individuals. Previous research on freshwater Unionida mussels showed that hermaphroditic species do not have DUI even if their closest gonochoristic counterparts do. No records showing DUI in a hermaphrodite have ever been reported.

Mitogenomics of (Bivalvia: Mytilidae) and its implications for doubly uniparental inheritance of mitochondria.

Animal mitochondria are usually inherited through the maternal lineage. The exceptional system allowing fathers to transmit their mitochondria to the offspring exists in some bivalves. Its taxonomic spread is poorly understood and new mitogenomic data are needed to fill the gap.

Actively transcribed and expressed gene in mussels.

Background: Animal mitochondrial genomes typically encode 37 genes: 13 proteins, 22 tRNAs and two rRNAs. However, many species represent exceptions to that rule. Bivalvia along with Nematoda and Platyhelminthes are often suspected to fully or partially lack the ATP synthase subunit 8 () gene.

Disruption of doubly uniparental inheritance of mitochondrial DNA associated with hybridization area of European and in Norway.

Doubly uniparental inheritance of mitochondria (DUI) is best known in the blue mussel . 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.

Complete female mitochondrial genome of .

The controversy surrounding the origin of antitropical distribution of mussels and the taxonomic status of southern hemisphere populations remain unsolved, despite the efforts. One of the limiting factors remains the lack of the complete sequences of the representative mitochondrial genomes which would allow their proper comparison with the relatively well-represented northern hemisphere congeneric mussels. To fill this gap we sequenced the representative maternal (F) genome of a native Chilean mussel.

Complete male mitochondrial genomes of European Mytilus edulis mussels.

Doubly uniparental inheritance (DUI) results in the existence of two gender-specific, divergent mtDNA lineages within a single species. Under DUI, the female genome (F) is transmitted from mothers to the whole offspring, and the male genome (M) is transmitted exclusively from fathers to sons. This system was first described in a marine mussels Mytilus edulis inhabiting European coastal waters, over a decade ago.

Recombinant mitochondrial genome with standard transmission route from Mediterranean mussel Mytilus galloprovincialis.

Several bivalve species, including marine mussels Mytilus are atypical in having two gender-specific and highly divergent mtDNA genomes. This peculiar genetic system allows not only the recombination to occur but also facilitates its detection. Previous reports associated the existence of mosaic recombinant haplotypes with the switch of their transmission route.

Molecular population genetics of male and female mitochondrial genomes in subarctic .

The doubly uniparental inheritance system allows for the use of two independent mitochondrial genomes for population history investigations. Under this system, two lineages of mitochondrial DNA (mtDNA) exist and males are typically heteroplasmic, having the additional, usually divergent, mitochondrial genome inherited from their male parent. This additional mtDNA typically evolves faster, potentially allowing for insight into more recent events in population history.

Comparative genomics of marine mussels (Mytilus spp.) gender associated mtDNA: rapidly evolving atp8.

The unusual mode of mitochondrial DNA inheritance, with two separate: maternal (F) and paternal (M) lineages, gives unique opportunities to study the evolution of the mitochondrial genome. This system was first discovered in the marine mussels Mytilus. The three related species: Mytilus edulis, Mytilus galloprovincialis and Mytilus trossulus form a complex in which the divergence of M and F lineages pre-dates the speciation.

Is interlineage recombination responsible for low divergence of mitochondrial nad3 genes in Mytilus galloprovincialis?

The existence of mtDNA recombination in animals has been confirmed by several case studies. Still, for Mytilus mussels possessing two divergent mitochondrial genomes (M and F), which can recombine, no recombination between coding sequences of highly diverged M and F genomes has been shown. Based on the full sequences of both genomes, it has been suggested that particularly low divergence observed within the mitochondrial nad3 gene of the Mytilus galloprovincialis mussel may be caused by its exceptionally low evolutionary rate.

Recombination in mitochondrial DNA of European mussels Mytilus.

Mitochondrial DNA was long believed to be purely clonal and free from recombination. Major phylogenetic studies still depend on such assumptions. The peculiar genetic system of marine mussels Mytilus in which two divergent mitochondrial genomes exist provides a unique opportunity to study mtDNA recombination.