Complete mitogenome of Anopheles sinensis and mitochondrial insertion segments in the nuclear genomes of 19 mosquito species

Abstract

Anopheles sinensis is a major malarial vector in China and Southeast Asia. The mitochondria is involved in many important biological functions. Nuclear mitochondrial DNA segments (NUMTs) are common in eukaryotic organisms, but their characteristics are poorly understood. We sequenced and analyzed the complete mitochondrial (mt) genome of An. sinensis. The mt genome is 15,418 bp long and contains 13 protein-coding genes (PCGs), two rRNAs, 22 tRNAs and a large non-coding region. Its gene arrangement is similar to previously published mosquito mt genomes. We identified and analyzed the NUMTs of 19 mosquito species with both nuclear genomes and mt genome sequences. The number, total length and density of NUMTs are significantly correlated with genome size. About half of NUMTs are short (< 200 bp), but larger genomes can house longer NUMTs. NUMTs may help explain genome size expansion in mosquitoes. The expansion due to mitochondrial insertion segments is variable in different insect groups. PCGs are transferred to nuclear genomes at a higher frequency in mosquitoes, but NUMT origination is more different than in mammals. Larger-sized nuclear genomes have longer mt genome sequences in both mosquitoes and mammals. The study provides a foundation for the functional research of mitochondrial genes in An. sinensis and helps us understand the characteristics and origin of NUMTs and the potential contribution to genome expansion.

Mitochondrial genome sequencing and phylogeny of Haemagogus albomaculatus, Haemagogus leucocelaenus, Haemagogus spegazzinii, and Haemagogus tropicalis (Diptera: Culicidae)

“…1-4). The tRNA Ser1 was the only one that did not present a secondary structure similar to the others, showing the absence of DHU arm, replaced by a DHU loop, similar to that reported in previous studies of other mosquito species 32,39,44,54 , and other groups of insects 31,48,56 . Besides, between 18 and 22 mismatched base pairs were detected in the tRNAs of the mitogenomes sequenced: in Hg.…”

“…The mitogenomes obtained here presented sets of 22 tRNAs, with approximate values in total lengths (average of 1488 bp), AT contents (average of 80.2%), and positive AT/GC-skews ( Supplementary Table 7A), similar to that reported for other species of Culicidae 40,44,54,55 . Individually, the average AT content in these regions ranged from 69.7% (tRNA Arg ) to 91.3% (tRNA Glu ) ( Fig.…”

“…In the first three species, there is an intergenic spacer with an average length of 174 nucleotides, located between rRNA 12 S and tRNA Ile . In this location, probably, the control region (A + T) of these species would be located 57 , as predicted in other Culicidae studies 32,41,45,54 , and other dipterans 31,46,47 . In Hg.…”

Nuclear Integrants of Organellar DNA Contribute to Genome Structure and Evolution in Plants

“…The nuclear integrants of organellar DNA were first discovered in a study in which a mitochondrial ATPase subunit gene was found in the nuclear genome, as well as in the mitochondrial genome of Neurospora crassa [25]. Since then, organelle-derived sequences were examined in the nuclear genome of a number of animals [26][27][28][29][30][31][32] and plants [15][16][17][18][19][20][21]. The availability of a large amount of plant organelle and nuclear genome data has made it possible to investigate the prevalence and characteristics of NUMTs and NUPTs in plants.…”

Giant viruses: spore‐like missing links between Rickettsia and mitochondria?

“…This phenomenon would have resembled nuclear inserts of mitogenomes, which are frequent in eukaryotic chromosomes (for nuclear mitochondrial DNA segments, see Refs. [80][81][82][83][84][85][86][87][88][89][90][91][92][93][94][95].…”