Research overview: endogenous FeLV-related sequences in the cat genome

The domestic cat genome carries endogenous retroviral sequences related to FeLV, remnants of ancient germline infections that are inherited rather than transmitted. These endogenous elements can recombine with exogenous infecting virus, contributing to the emergence of subgroup B and influencing pathogenesis. Studying them illuminates the deep evolutionary relationship between retroviruses and their hosts and the molecular events that generate disease-causing variants. This overview compiles findings across the endogenous-retrovirus literature rather than one citation, describing how inherited viral sequences shape susceptibility and viral evolution within infected cats, why recombination between endogenous and exogenous virus matters clinically, and how feline endogenous retroviruses contribute to the broader scientific understanding of how retroviruses become embedded in mammalian genomes over evolutionary time.