Uneven evolutionary rate of the melatonin-related receptor gene (GPR50) in primates

Abstract

ABSTRACT. The melatonin-related receptor GPR50 plays an important role in mammalian adaptive thermogenesis in response to calorie intake. The evolutionary history of the GPR50 gene is poorly understood in primates; however, it has been reported that GPR50 is the mammalian ortholog of Mel1c, which has been well characterized. In this study, the complete coding sequences of the GPR50 gene in the Sichuan snub-nosed monkeys (Rhinopithecus roxellana) and Tibetan macaques (Macaca thibetana) were sequenced, and the orthologous nucleotide acid sequences of the GPR50 gene in 11 other primate species were downloaded from GenBank. Thirteen species representing 6 major primate lineages (human, great ape, lesser ape, Old World monkey, New World monkey, and prosimian monkey) were subjected to statistical analyses. A selective test showed that the entire GPR50 gene sequence is under strong purifying selection in these primates but has a significantly different evolutionary rate among the 6 major primate Evolution of GPR50 gene in primates lineages. Notably, both the Homo and Pan branches exhibited an ω ratio >1, indicating accelerated evolution of the two lineages. Further analysis of different domains revealed that the acceleration trend was more significant in the C-terminal domain (CTD). Interestingly, in the alignment of 13 primate GPR50 nucleotide acid sequences, numerous insertions or deletions were only found in the CTD region, implying that this region may play a key role in the process of primate GPR50 evolution. The results provide deeper insight into the functional evolution of GPR50 in mammals at the molecular level.

Gamete Recognition Gene Divergence Yields a Robust Eutherian Phylogeny across Taxonomic Levels

“…To compare relationships of positive selection to phylogenetic support more broadly across Zan and other molecular markers, we constructed individual Bayesian phylogenies and performed corresponding PAML selection analyses for all reliable sequences of all eutherian genes (n = 40) previously shown to have evolved by positive selection (as of June 2022; [47,51,[67][68][69][70][71][72][73][74][75][76][77][78][79][80][81][82][83]). Annotated gene functions ranged from reproduction (n = 23) to sensory perception (n = 7), immunity (n = 5), metabolism (n = 3), the nervous system (n = 1), and the cell cycle (n = 1), and the genes' compared sequence lengths ranged from 394 nt (for S100a2) to 8016 (for Cr2) nt (Table 1), collectively encompassing >104,000 nt of gene coding sequence.…”

Rapid divergence of a gamete recognition gene promoted macroevolution of Eutheria

“…To assess relationships of positive selection to phylogenetic support more broadly, we retrieved all reliable sequences of all genes previously shown to have evolved by positive selection [24,91,95,100,[107][108][109][110][111][112][113][114][115][116][117][118][119][120][121][122] and conducted Bayesian and selection analyses on individually constructed gene trees. Excluding 12 genes with too little taxonomic representation (either fewer than nine Orders total or no basal Orders), the analysis yielded Bayesian (>95% posterior support) and M7 and M8 model selection data (magnitude = dN/dS = ω, and frequency= f) for 40 positively selected genes with widely ranging functions, including 23 genes that function in reproduction, seven in sensory perception, five in immunity, three in metabolism, and one each in the nervous system and the cell cycle.…”