bims-humivi Biomed News
on Human mito-nuclear genetic interplay
Issue of 2026–04–05
two papers selected by
Mariangela Santorsola, Università di Pavia
  1. Sensitivity of genome-wide tests for mitonuclear genetic incompatibilities.
  2. Mitonuclear dynamics in unisexual vertebrates.
  1. Philos Trans R Soc Lond B Biol Sci. 2026 Apr 02. pii: 20250084. [Epub ahead of print]381(1947):
    Sensitivity of genome-wide tests for mitonuclear genetic incompatibilities.
    Shady A Kuster, Molly Schumer, Justin Havird, Daniel B Sloan.
      Mismatches between interacting mitochondrial and nuclear gene products in hybrids have been proposed to disproportionately contribute to early species boundaries. Under this model, genetic incompatibilities emerge when mitochondrial haplotypes are in a cellular context without their coevolved nuclear-encoded mitochondrial (n-mt) proteins. Some case studies have shown that such disruptions in mitonuclear coevolution can contribute to reproductive isolation, but whether mitonuclear incompatibilities generate selection that impacts multiple n-mt loci and/or causes broad, genome-wide contributions to speciation is unclear. Here, we leverage a system with several hybridizing species pairs (Xiphophorus fishes) that have known mitonuclear incompatibilities of large effect. We divided nuclear-encoded genes into three classes based on level of interaction with mitochondrial gene products. We found only inconsistent statistical support for a difference between these classes in the degree of positive covariation in mitonuclear ancestry. We discuss evidence that these analyses are sensitive to the amount of non-synonymous divergence between parent species in interacting n-mt genes or the age of the hybridization event. Overall, our results imply that genome-wide scans focused on enrichment of broad functional gene classes may often be insufficient for detecting a history of mitonuclear coevolution, even when strong selection is acting on mitonuclear incompatibilities at multiple loci. This article is part of the theme issue 'Evolutionary genetics of mitochondria: on diverse and common evolutionary constraints across eukarya'.
    Keywords:  genomics; hybrid incompatibilities; mitochondrial evolution; mitonuclear coevolution; n-mt genes
    DOI:  https://doi.org/10.1098/rstb.2025.0084
  2. Philos Trans R Soc Lond B Biol Sci. 2026 Apr 02. pii: 20250081. [Epub ahead of print]381(1947):
    Mitonuclear dynamics in unisexual vertebrates.
    Randy L Klabacka, Geoffrey E Hill, Damian K Dowling, Joel Sharbrough, Robert D Denton, Joshua M Hall, Justin C Havird.
      Sex and mitochondria are inextricably linked in the eukaryotic tree of life, a confounding situation given the uniparental inheritance of mitochondria and the biparental inheritance that sexual reproduction entails. Unisexual vertebrate lineages, which arise via hybridization and asexually pass on their genetic material to clonal descendants, provide a unique opportunity to study mitochondrial evolution without potentially confounding effects of sex. Hybridity and clonality set unisexual vertebrates apart from other vertebrates and establish a distinct genetic environment that shapes their evolution, especially dynamics between mitochondrial and nuclear genomes. Here, we provide a perspective on the mitonuclear genomic interactions experienced by unisexual vertebrates and the implications of these interactions on mitochondrial function and integration into organismal performance and fitness. Building upon the hypothesis that sexual reproduction arose to maintain coadaptation between co-functioning nuclear and mitochondrial genes, we propose that unisexual vertebrates may be confined to predominantly 'young' lineages because mitonuclear incompatibilities-arising from either hybridity or clonality-increase the probability of extinction over time (the Mitonuclear Erosion Hypothesis). We provide a multidisciplinary collection of strategies to disentangle the effects of clonality and hybridity and quantify the relative degree to which these characteristics contribute to differences in mitochondrial function, organismal performance and fitness. This article is part of the theme issue 'Evolutionary genetics of mitochondria: on diverse and common evolutionary constraints across eukarya'.
    Keywords:  asexual reproduction; mitochondrial function; mitonuclear incompatibility; unisexual; vertebrates
    DOI:  https://doi.org/10.1098/rstb.2025.0081
This page is being maintained by Thomas Krichel. It was last updated on 2026‒04‒05 at 8:00.