Phylogeny of orthologs of β-esterase genes outside of Drosophila genus

Abstract

β-esterase genes of Drosophila have important functions and are present in all members of the genus. The most studied member of these genes is Est-6 gene of D. melanogaster. There are no data yet about presence and numbers of these genes in another insects and their molecular evolution is unknown. With the help of search tool BLAST there have been found orthologous sequences of the Est-6 gene of D. melanogaster in 10 species of insects belonging to 5 orders. It has been shown that the sequences of β-esterases of Drosophila belong to the same cluster with orthologous sequences of Anopheles gambie, Aedes aegypti and Culex quinquefasciatus (order Diptera). Its sister cluster consists of orthologous sequences of other orders of infraclass Neoptera. There have been not detected orthologs of the Est-6 gene in the representatives of the taxon Crustacea (Daphnia pulex), Myriapoda (Strigamia maritima) and Chelicerata (Tetranychus urticae). With the help of the TimeTree instrument there has been substantiated the probable time period of possible origin of genes which are orthologous to β-esterase genes of Drosophila. The hypothesis of the origin of genes which were the ancestral to β-esterases of Drosophila on the early stages of development of the class Insecta is discussed.