Across species identification of genes bridging neurological and reproductive functions in mammals.

Evolutionary success in mammals depends on coordinated neurological and reproductive functions, likely mediated by shared genes and molecular pathways between the brain and germ cells. However, direct evidence across species remains limited. Here, proteomic and transcriptomic analyses were performed experimentally in Ovis aries and Rattus norvegicus, while transcriptomic datasets from Mus musculus, Macaca mulatta, and Homo sapiens were analyzed in silico. We identified 8,464 protein-coding genes shared between the brain and sperm/testis and conserved across five species. In rats, 8,444 of these genes were also shared between the brain and the ovary. Functional annotation classified 3,890 genes as associated with both neurological and reproductive functions, and 1,752 as uncharacterized in these contexts, highlighting candidates for future studies on reproductive and neurological disorders. These findings identify a set of conserved genes shared between neurological and reproductive systems, implying a potential genetic network underlying evolutionary conservation of molecular functions across these systems.