LCAT acts as a molecular switch and regulates rooster sperm motility in vitro.

Sperm motility is a critical determinant of semen quality, yet the molecular mechanisms regulating motility remain unclear. In this study, we identified Yufen 1 roosters with significant differences in sperm motility among highly motile sperm samples stored under different conditions. By integrating the seminal plasma proteome and seminal plasma metabolome data, 181 proteins and 112 metabolites were identified as differentially expressed between the high motility group (HMG) and low motility group (LMG). Lecithin cholesterol acyltransferase (LCAT) was upregulated in the LMG. Targeted LCAT activation significantly reduced sperm motility and plasma membrane integrity, caused sperm plasma membrane disruption, chromatin loss, and mitochondrial swelling, and reduced the longest fertilization days and number of fertilized eggs. Mechanistically, LCAT regulates sperm motility in vitro by altering sperm membrane structure and function by modulating glycerophospholipid metabolism. These findings provide new insights into extending the window period for artificial insemination and semen preservation strategies in poultry.