Exploring the Relationship Among Divergence Time and Coding and Non-coding Elements in the Shaping of Fungal Mitochondrial Genomes

Abstract

Divergence Time and Mitogenome Shaping and investigated its relationship with coding and non-coding elements as well as with the length of mitogenomes. Altogether, our results demonstrated that introns and HEGs are key elements on mitogenome shaping and its presence on fast-evolving mtDNAs could be mostly explained by its divergence time, although the intron sharing profile suggests the involvement of other mechanisms on the mitochondrial genome evolution, such as horizontal transference.

Mitochondrial evolution in the entomopathogenic fungal genus Beauveria

“…These results suggest that the presence or absence of mitochondrial introns cannot serve as a taxonomic marker in themselves, and that care should be taken to remove these highly dynamic sequences from phylogenetic analyses. However, a recent study by Fonseca et al (2020) estimated that there may be a correlation between the divergence time of each Hypocrealean fungal species they investigated and the quantity of coding and noncoding elements in the mtDNA, in addition to the effect these elements have on the length of mitochondrial genomes between species. They showed that introns and HEGs are key components on mitochondrial genomes in that the presence of these elements indicates more rapidly evolving mtDNA, which could be partially explained by species divergence time, despite that the intron pattern shared between species suggests the involvement of other mechanisms of evolution, such as horizontal transference.…”

“…These results suggest that the presence or absence of mitochondrial introns cannot serve as a taxonomic marker in themselves, and that care should be taken to remove these highly dynamic sequences from phylogenetic analyses. However, a recent study by Fonseca et al (2020) estimated that there may be a correlation between the divergence time of each Hypocrealean fungal species they investigated and the quantity of coding and noncoding elements in the GLARE ET AL. mtDNA, in addition to the effect these elements have on the length of mitochondrial genomes between species.…”

“…Very few studies have examined the mitochondria genomes of Beauveria species and the relationship between mitochondrial variation and genome variation is largely unknown. It is well known that the evolutionary rate of fungal mitochondrial DNA (mtDNA) is close to that of plants, which have low nucleotide substitution rates (Aguileta et al, 2014; Fonseca et al, 2020). The rate of evolution is based on the percentage of base substitutions observed in conserved genetic regions.…”

“…Clark‐Walker (1992) demonstrated that the percentage of substitution in mitochondrial genes was lower than that of nuclear genes, indicating that fungal mitogenomes may evolve more slowly compared to their respective nuclear genomes. Insights from recent genomic studies of other species demonstrate how fungal mitochondrial genomes can mutate at a different rate than nuclear genomes (Fonseca et al, 2020; Li et al, 2019; Ying et al 2020). Fonseca et al (2020) observed that among 34 mitochondrial genomes of fungal species compared within the order Hypocreales, there was significant variation in both structure and length.…”

“…Insights from recent genomic studies of other species demonstrate how fungal mitochondrial genomes can mutate at a different rate than nuclear genomes (Fonseca et al, 2020; Li et al, 2019; Ying et al 2020). Fonseca et al (2020) observed that among 34 mitochondrial genomes of fungal species compared within the order Hypocreales, there was significant variation in both structure and length. The number and size of noncoding DNA, such as Groups I and II introns and homing endonucleases genes (HEGs), were thought to be the main contributors to these differences.…”