Function of <i>Bcl-2</i> gene and its mechanism on body size adaptive evolution in primates.

Significant body size variations exist among different primate species. To investigate the genes influencing primate body size evolution, this study employed evolutionary genetics approaches to analyze functional differences and natural selection patterns of genes across species with distinct body sizes. Six primate species representing significant size variations were selected. Through comparative analysis of genome, molecular evolution and RNA-seq, <i>Bcl-2</i> gene was detected and it has a significant impact on primate body size. Results demonstrated a positive correlation between <i>Bcl-2</i> gene expression levels with body size, with differential natural selection observed among species of varying sizes. Population genetic analysis identified specific <i>Bcl-2</i> SNP loci associated with body size evolution, and cellular experiments confirmed that this gene regulates osteoblast proliferation through pathways such as Wnt/β-catenin and BMP signaling. Multi-omics analysis further revealed that <i>Bcl-2</i> expression increases with body size and exhibits significant selection signals and physicochemical property differences between species with substantial size variations. Functional studies indicated that <i>Bcl-2</i> plays a crucial role in body size evolution by regulating skeletal development-related pathways. This study systematically reveals <i>Bcl-2</i> as a key regulatory factor influencing primate adaptive body size evolution through processes such as apoptosis, skeletal development, and metabolism. From an evolutionary genetics perspective, it elucidates the molecular mechanisms underlying body size differences, providing new insights into primate body size evolution.