Evolutionary Study of DGAT1 Gene Indicates the Presence of Positive Selection in Mammals

Abstract

This study was focused on the evolving role of DGAT1 using phylogenetic analysis. DGAT1 was retrieved from available databases of 37 mammalian genomes to detect signatures of positive selection in individual codons. Evolutionary analyses likelihood (REL), fast unconstrained Bayesian approximation (FUBAR), and Mixed-effects model evolution (MEME). REL detected 3 positive selection sites (at 109, 195, and 211 positions), and MEME detected 20 sites. Among them, 211 sites were confirmed as a strong positive selection of the DGAT1 gene. The codon model evolution (CME) model clustered amino acid substitution rates at three class levels (0.06, 0.20, and 0.40). Multiple hit tests showed that 20 of the DGAT1 triplet codes for amino acid formation were changed into new codes. In which, the GAC code for aspartate and GTC for valine had the maximum counts of 14 and 16. Strong evidence of positive selection of the DGAT1 gene in mammals was found.