Analyses of RAG1 and RAG2 genes suggest different evolutionary rates in the Cetacea lineage

Autor(es)

Dias, Bruna C. ^[1] ; Nery, Mariana F. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Dept Genet Evolut Microbiol & Immunol, Lab Evolutionary Genom, Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Molecular Immunology; v. 117, p. 131-138, JAN 2020.
• Citações Web of Science: 0

Resumo

V(D)J recombination is a process of somatic recombination catalyzed by proteins encoded by RAG1 and RAG2 genes, both restricted to the genome of jawed vertebrates. Their proteins constitute the enzymatic core of V(D)J recombination machinery and are crucial for jawed vertebrate adaptive immunity. Mammals possess great ecological diversity, and their complex evolutionary history associated with radiation to different environments presented many distinct pathogenic challenges from these different habitats. Cetaceans comprise a mammalian order of fully aquatic mammals that have arisen from a complete terrestrial ancestor and, accordingly, was confronted with challenges from changing environmental pathogens while they transitioned from land to sea. In this study we undertook molecular evolutionary analyses of RAG1 and RAG2 genes, exploring the possible role of natural selection acting on these genes focusing on the cetacean lineage. We performed phylogenetic reconstructions on IQ-TREE, together with selection analyses in the codeml program of the PAML package, and in the FITMODEL program for codon evolution and switching on both the RAG1 and RAG2 genes. Our findings demonstrate that RAG1 and RAG2 remained fairly conserved among tetrapods, with purifying selection acting on both genes, with evidence for a few punctuated shifts in nucleotide substitution rates of both genes along tetrapod evolution. We demonstrate differential evolution in the closely linked genes RAG1 and RAG2 specifically in cetaceans. (AU)

• Processo FAPESP: 15/18269-1 - Usando genômica comparativa para entender a evolução convergente de mamíferos: em busca das pegadas moleculares da ocupação do ambiente marinho e fluvial
• Beneficiário: Mariana Freitas Nery
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 17/14831-2 - Evolução de genes do sistema imunológico em mamíferos aquáticos: identificando as pegadas moleculares da colonização de novos ambientes
• Beneficiário: Bruna Cristina Dias
• Modalidade de apoio: Bolsas no Brasil - Mestrado