AUTHOR=Wu Haixia , Gao Shuo , Xia Longjie , Li Peng 

TITLE=Evolutionary rates of body-size-related genes and ecological factors involved in driving body size evolution of squamates

JOURNAL=Frontiers in Ecology and Evolution

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/ecology-and-evolution/articles/10.3389/fevo.2022.1007409

DOI=10.3389/fevo.2022.1007409

ISSN=2296-701X

ABSTRACT=<p>Body size is one of the most important traits of an organism. Among reptiles, both lizards and snakes show body size differences that span a similar six orders of magnitude variation. However, the molecular mechanisms underlying body size variation in squamates remain obscure. Here, we performed comparative genomic analyses of 101 body-size-related genes from 28 reptilian genomes. Phylogenetic analysis by maximum likelihood (PAML) revealed that snakes showed higher evolutionary rates in body-size-related genes, and had an almost two-fold increase in the number of positively selected genes (∼20.3%) compared with lizards (∼8.9%). The high similarities in dN/dS values were obtained between the branches of large-bodied lizards and large-bodied snakes by Spearman correlation analysis. Combining the results from site model, branch-site model and clade model analyses, we found some key genes regulating the evolution of body size in squamates, such as <italic>COL10A1</italic>, <italic>GHR</italic>, <italic>NPC1</italic>, <italic>GALNS</italic>, <italic>CDKN2C</italic>, <italic>FBN1</italic>, and <italic>LCORL</italic>. Phylogenetic generalized least squares (PGLS) indicated that <italic>AKT1</italic>, <italic>BMP1</italic>, <italic>IGF1</italic>, <italic>SOX5</italic>, <italic>SOX7</italic> in lizards and <italic>BMP5</italic>, <italic>BMP7</italic>, <italic>GPC6</italic>, <italic>SH2B3</italic>, <italic>SOX17</italic> in snakes were significantly correlated with body length and body mass. Furthermore, ecological factors had varying degrees of impact on body size and the evolutionary rate of body-size-related genes in squamates. Intriguingly, climate had little effect on body size of lizards and snakes, but the contribution of climate-related factors to the variation in evolutionary rate of body-size-related genes were relatively higher. Our study lays a foundation for a comprehensive understanding of genetic mechanisms of body size evolution in squamates during the process of adapting to terrestrial life.</p>