Long-Lived Species of Bivalves Exhibit Low MT-DNA Substitution Rates

Abstract

Bivalves represent valuable taxonomic group for aging studies given their wide variation in longevity (from 1–2 to >500 years). It is well known that aging is associated to the maintenance of Reactive Oxygen Species homeostasis and that mitochondria phenotype and genotype dysfunctions accumulation is a hallmark of these processes. Previous studies have shown that mitochondrial DNA mutation rates are linked to lifespan in vertebrate species, but no study has explored this in invertebrates. To this end, we performed a Bayesian Phylogenetic Covariance model of evolution analysis using 12 mitochondrial protein-coding genes of 76 bivalve species. Three life history traits (maximum longevity, generation time and mean temperature tolerance) were tested against 1) synonymous substitution rates (dS), 2) conservative amino acid replacement rates (Kc) and 3) ratios of radical over conservative amino acid replacement rates (Kr/Kc). Our results confirm the already known correlation between longevity and generation time and show, for the first time in an invertebrate class, a significant negative correlation between dS and longevity. This correlation was not as strong when generation time and mean temperature tolerance variations were also considered in our model (marginal correlation), suggesting a confounding effect of these traits on the relationship between longevity and mtDNA substitution rate. By confirming the negative correlation between dS and longevity previously documented in birds and mammals, our results provide support for a general pattern in substitution rates.

In both directions: Expansions of European land snails to the north and south from glacial refugia

“…Large intraspecific divergences have been observed in stylommatophoran land snails since very early studies of their mitochondrial variation (Thomaz et al, 1996), but the value found here for M. incarnatus is particularly high. This may be due to a higher substitution rate, which is supposed to be associated with smaller body size and shorter generation time (Bromham, 2020; Mortz et al, 2021; Nabholz et al, 2008). In H. pomatia it takes at least 2–4 years to reach maturity (Frömming, 1954; Ligaszewski et al, 2016; Pollard, 1975) and the same may be assumed for H. thessalica .…”

Contrasting Modes of Mitochondrial Genome Evolution in Sister Taxa of Wood-Eating Marine Bivalves (Teredinidae and Xylophagaidae)

“…Although we can infer differences based on their distinct respiratory demands, reproductive strategies, bathymetric ranges and the environmental variables that characterize these distributions, distinguishing between these alternatives, or other explanations will require more taxon sampling and better understanding of wood-boring bivalve phylogeny and ecology. Perhaps the most interesting feature of this data set is the contrasting patterns observed in the two families with respect to rates of sequence evolution and rates of genome rearrangement, phenomena which previously have been proposed to be positively correlated ( Mortz et al 2021 ). While we cannot currently explain these differences, the presented data provide fertile ground for exploration of the environmental, biological, and molecular mechanisms that shape the tempo and mode of mitochondrial evolution.…”

Direct multiplex PCR-NALFIA to inform marine conservation: Use of an innovative diagnostic tool for the detection of Ostrea edulis larvae

“…(3) it does not undergo genetic rearrangements such as recombination; and (4) sequence ambiguities resulting from heterozygous genotypes are avoided. Especially the mitochondrial cytochrome b (mtCytB) is particularly suitable as a species-specific target because mtCytB is maternal inherited and interspecifically conserved, so even closely related and ubiquitous species can be distinguished (Cronin et al, 1991;Danic-Tchaleu et al, 2011;Mortz et al, 2021).…”