Increased Rate of Gene Rearrangement in the Mitochondrial Genomes of Three Orders of Hemipteroid Insects
2001; Oxford University Press; Volume: 18; Issue: 9 Linguagem: Inglês
10.1093/oxfordjournals.molbev.a003970
ISSN1537-1719
AutoresRenfu Shao, Nick Campbell, E. R. Schmidt, Stephen C. Barker,
Tópico(s)Insect symbiosis and bacterial influences
ResumoThe mitochondrial (mt) genomes of most animals studied so far are circular, are about 16 kb in size, and have 13 protein-coding genes (atp6 and atp8 for ATP synthase subunits 6 and 8, cox1–cox3 for cytochrome oxidase subunits 1–3, cob for cytochrome b, nad1–nad6 and nad4L for NADH dehydrogenase subunits 1–6 and 4L), two rRNA genes (rrnL and rrnS for large and small rRNA subunits), 22 tRNA genes (one for each amino acid except for leucine and serine, which have two genes: trnL1 [anticodon sequence tag], trnL2 [taa], trnS1 [gct], and trnS2 [tga]), and one major noncoding region (Wolstenholme 1992). The arrangement of these 37 genes, especially the arrangement of the large genes that encode proteins and rRNAs, is usually conserved in a phylum but varies substantially among phyla (Boore and Brown 1998). However, the arrangement of protein-coding and rRNA genes has also been found to differ at lower taxonomic levels, e.g., in the family Ixodidae (Campbell and Barker 1998, 1999) and in the genus Schistosoma (Le et al. 2000). The arrangement of genes in mt genomes has been studied in more insects than any other group of invertebrates. So far, 15 species of insects have had their mt genomes sequenced completely: eight flies (order Diptera; Clary and Wolstenholme 1985; Lewis, Farr, and Kaguni 1995; Ballard 2000; Lessinger et al. 2000; Spanos et al. 2000; Junqueira et al., unpublished but available in GenBank, accession number NCp002697); two mosquitoes (Diptera; Beard, Hamm, and Collins 1993; Mitchell, Cockburn, and Seawright 1993); the silkworm Bombyx mori (Lepidoptera; Lee et al., unpublished but available in GenBank, accession number AF149768); the honeybee Apis mellifera (Hymenoptera; Crozier and Crozier 1993); the locust Locusta migratoria (Orthoptera; Flook, Rowell, and Gellissen 1995); the bug Triatoma dimidiata (Hemiptera; Dotson and Beard 2001; accession number AF301594); and the wallaby louse Heterodoxus macropus (Phthiraptera; Shao, Campbell, and Barker 2001). Furthermore, part of the arrangement of mt genes is known for another 451 species of insects. The species of insects studied prior to this study were from 11 orders, but the vast majority were from four orders: Lepidoptera, Diptera, Hymenoptera, and Hemiptera. The first three orders are in the Endopterygota,
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