Composition characteristics of the Mitochondrial encoded COX1 gene of Triatominae (Heteroptera: Reduviidae)

Author: J. Sherlin John and P. Selvaraj

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Abstract

Triatominae is the only hematophagous subfamily of Reduviidae. They are vectors of Trypanosoma cruzi which causes Chagas’ disease. Complete mitochondrial genomes provide reliable phylogenetic information from its highly conserved protein-coding genes including MT-COX1, which is widely used in molecular phylogenetics. This study investigated the compositional characteristics of the MT-COX1 gene of 11 Triatominae species to detect the variations/patterns which support phylogenetic systematics. Curated mitogenomes of various species in Triatoma are more in Refseq than other genus in Reduviidae. The AT biased nucleotide composition showed negative AT and GC skewness. Leucine and isoleucine dominate the amino acid composition. When comparing the MT-COX1 coding gene among the 11 species, 83.45 ± 2.90% genetic identity with heat map analysis showing the divergence among the tribes. Amino acids with hydrophobic side-chains (especially Leu and Ile) are subjected to conservative substitutions. Non-conservative substitutions are more favored than semi-conserved mutations. An 86.49% threshold of identical amino acids in the MT-COX1 is prominent within the subfamily. This study encountered challenges in delineating validated nucleotide sequences, analyzing them within the framework of established morphological systematics and elucidating the mechanisms underlying molecular evolution within the gene. Thus, studying the basic compositional variations in the protein-coding genes like MT-COX1 substantiate mechanisms of evolution in Triatominae. The highly variable amino acid sequence from 472 to 492 of MT-COX1 and corresponding coding region in the gene can delimit species in Triatominae. Gaining insight into the fundamental compositional variations within dependable protein-coding genes, such as MT-COX1, not only enhances the validation of classical taxonomy through molecular systematics but also reveals contrariety in the phylogenetic relationship of Triatominae, extending up to the level of Tribes.

Keywords

Insect vectors, Hematophagy, Mitochondria, Amino acid, Systematics, Phylogeny

Conclusion

The amino acid sequence from 472 to 492 identified variation among the species in Triatoma. Hence, the corresponding coding region of 472 to 492 amino acids in the gene can delimit species in Triatominae (Fig. 5). Future studies are needed to compare this region with other species in Triatominae. When comparing all the results of this study, leucine and isoleucine, being the most abundant amino acids, are subjected to conservative mutations. A threshold of 86.49% identical amino acids and a very close 83.45 ± 2.90 (Mean ± S.D.) genetic identity (%) is prominent within the subfamily.

References

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How to cite this article

J. Sherlin John and P. Selvaraj (2023). Composition characteristics of the Mitochondrial encoded COX1 gene of Triatominae (Heteroptera: Reduviidae). Biological Forum – An International Journal, 15(6): 636-642.