Pacific Ocean rockfish genomes reveal genetic drivers of extreme life span

Genomes assembled from Pacific Ocean rockfishes – some species of which are among the longest-living vertebrates known – reveal new insights into the genetic determinants of aging. “Humans live longer than most vertebrates, but long-lived rockfish can offer humans strategies for improvement,” write J. Yuyang Lu and colleagues in a related Perspective. “Genetic adaptations found in rockfish illustrate that strategies that improve DNA repair and control inflammation may extend life span and health span.” Although vertebrate species have evolved an astounding diversity of lifespans, from a 5-week life cycle to a 400-year lifespan, most share several distinct hallmarks of aging that are also directly linked to human health and disease, including immunosenescence, inflammation and stem cell exhaustion. According to Sree Rohit Raj Kolora and colleagues, understanding the genetic basis of lifespan variation across vertebrates can provide important insights into human health and activity in old age. Rockfishes of the Pacific Ocean exhibit considerable variation in lifespan, ranging from 11 years to as many as 200. This diversity among closely related species provides a unique opportunity to study the genetic origin and evolution of extreme lifespan adaptations. To identify the genetic drivers of longevity in these creatures, Kolora et al. sequenced and performed a genomic analysis of 88 different long- and short-lived rockfish species. From this analysis, the authors identified repeated signatures of positive selection in DNA repair pathways in long-lived taxa and 137 longevity-associated genes that affect life span both directly, through influencing insulin signaling and other pathways, as well as indirectly, by affecting size and environmental adaptations. The findings illustrate the genetic innovations that underlie the diversity of life histories among rockfishes. Kolora et al. also revealed an expansion of the immunosuppressive butyrophillin gene family in long-lived rockfish, suggesting that these species have more control over inflammaging, or the increased systemic inflammation with age, which may play an important role in modulating life span.