Evolutionary divergence of mitochondrial genomes in two Tetranychus species distributed across different climates

Abstract

There is increasing evidence that mitochondrial genomes (mitogenomes) can be under selection, whereas the selective regimes shaping mitogenome evolution remain largely unclear. To test for mitogenome evolution in relation to the climate adaptation, we explored mtDNA variation in two spider mite (Tetranychus) species that distribute across different climates. We sequenced 26 complete mitogenomes of Tetranychus truncates, which occurs in both warm and cold regions, and nine complete mitogenomes of Tetranychus pueraricola, which is restricted to warm regions. Patterns of evolution in the two species' mitogenomes were compared through a series of d /d methods and physicochemical profiles of amino acid replacements. We found that: (1) the mitogenomes of both species were under widespread purifying selection; (2) elevated directional adaptive selection was observed in the T. truncatus mitogenome, perhaps linked to the cold climates adaptation of T. truncatus; and (3) the strength of selection varied across genes, and diversifying positive selection detected on ND4 and ATP6 pointed to their crucial roles during adaptation to different climatic conditions. This study gained insight into the mitogenome evolution in relation to the climate adaptation.

Mitochondrial variation in small brown planthoppers linked to multiple traits and probably reflecting a complex evolutionary trajectory

“…Previous studies on a range of taxa suggest amino acid variation in ND3 , ND4 , ND5 , ND6 , CYTB , and ATP6 are probably associated with climatic adaptation (Balloux et al, ; Lamb et al, ; Morales et al, ; Silva et al, ; Sun et al, ). Those changes are presumed to affect mitochondrial coupling efficiency, coordinating the ratio of ATP synthesis efficiency to thermogenesis efficiency, helping organisms to adapt to different conditions.…”

“…Previous studies on a range of taxa suggest amino acid variation in ND3, ND4, ND5, ND6, CYTB, and ATP6 are probably associated with climatic adaptation (Balloux et al, 2009;Lamb et al, 2018;Morales et al, 2015;Silva et al, 2014;Sun et al, 2018).…”

Characterization of the mitochondrial genomes of two toads, Anaxyrus americanus (Anura: Bufonidae) and Bufotes pewzowi (Anura: Bufonidae), with phylogenetic and selection pressure analyses

“…Thus, the adaptive changes in several ND4 and ND6 gene sites may affect the proton-pumping process and metabolic performance (Yu et al, 2011). Sun et al (2018a) found positive selection on ND4 from Tetranychus truncatus during adaptation to low temperature. Zhuang & Cheng (2010) proposed that the modification of ND6 gene probably improved complex I subunit interactions at low temperatures after analyzing positive selection results.…”

“…Numerous environmental factors can affect the growth and survival of amphibians, including temperature and salinity (Yaghobi et al, 2018). Temperature has a great effect on the bioenergetic demands and metabolic adaptation of ectotherms (Sun et al, 2018a). For example, negative selection was found in the mitochondrial protein-coding genes of Glandirana (Xia et al, 2014).…”

Purifying selection can reduce intraspecific mitochondrial gene variation to that of nuclear rRNA

“…When mutations in mitochondrial genes occur at fewer sites than expected under the neutral model (Lawrie et al 2013), molecular dating of historical demographic events by means of evolutionary rate estimates that are typically based on inter-specific divergence (Knowlton and Weigt 1998;Schubart et al 1998) will result in considerable underestimates. This is particularly likely because divergence between species can be strongly affected by diversifying selection that is driven by different environmental conditions (Lamb et al 2018;Sun et al 2018), resulting in a faster accumulation of mutations characterising each species than is expected under the neutral model.…”