Evolution Of Mitochondrial Genomes In Oribatida Mites

Oribatida belong to the subclass Acari,head mites,and scabies.The mites of this group have diverse forms,rich species,and diverse living environments.They are the most diverse,complex,and most studied terrestrial ecological groups of biological communities.One,is increasingly receiving widespread attention from biologists.According to the current classification system,the subfamilies of Oribatida include onychomycosis and anemonoid mites,but the relationship between the two is still controversial.This article takes the unique whole mitochondrial genome presented by this group of mites as the research object and analyzes the characteristics of its whole mitochondrial genome;using the nucleotide sequence of the whole mitochondrial genome to construct a phylogenetic tree,with a view to clarifying the various groups of Oribatida Phylogenetic relationship.The main findings are as follows:(1)Annotation and determination of the entire mitochondrial genome sequence of five species of Acaridae.The mitochondrial genome lengths of the five species of mites are:14,711 bp,15,220 bp,14,255 bp,14,511 bp,and 14,915 bp.The mitochondrial genomes of these five species of mites are double-stranded circular closed DNA molecules,and all contain 37 genes(13 protein-coding genes,22 transport RNAs,and 2 ribose rRNAs),without gene deletion and duplication.(2)Through the analysis of the components of the mitochondrial genomes of the five species of mite mites,it is found that the base composition of the entire mitochondrial genome and protein-coding genes of these five species of mites are all A+T content higher than G+C content.Obvious A+T bias;except for Hermannia gibba's ND4L gene,all five mite protein-coding genes use ATN as a start codon;the five mite tRNA secondary structures all have different degrees of D arm or T In addition to the deletion of the arm,it was also found that the trnR genes of five mites were all missing the D and T arms.This phenomenon may be a common trait of the nymphalidae.(3)By comparing the base composition and gene arrangement order of 19 species of the Acaroididae,we found that the mitochondrial genome size and nucleotide composition of the acarid mites and airless mite groups were not significantly different,and were skewed at AT.The difference in deviation from GC is obvious.The mitochondrial genome of the mite group prefers base A and base C,while the mitochondrial genome of the non-valvular group prefers base T and base G.In the mitochondrial gene arrangement,the gene order of the 19 species has been rearranged relative to the assumed ancestral arrangement pattern of arthropods.(4)By reconstructing the phylogenetic tree,it was found that the Anoptera grouped together as a monophyletic group nested in the Acaroid suborder,while the traditional Acarida mites were considered to be a polyphyletic group.In the future,this result is consistent with the morphological and nuclear gene fragment inference results.In addition,the change in gene order in the mitochondrial genome characterizes the different lineages of onychomycosis and acarid mites,and has available phylogenetic signals,which can be used to elucidate the taxonomic relationship of higher order elements of the true mite head.Later,the mitochondrial genome of the mite suborders needs to be further sequenced to better elucidate the evolutionary trend of the mitochondrial mitochondrial genome(from ancient patterns to intense rearrangements),time of origin,and speed of evolution.