biostudies-literatureUnknownBock SLU.S. National Science FoundationNIA NIH HHSNational Institute on AgingSexes frequently differ in life history traits including body size, lifespan, and age at sexual maturity. Aging, the progressive decline in physiological function and cellular resilience over time, is a central process contributing to sex-specific life histories, yet the mechanisms driving sex differences in aging remain largely unresolved. Long-term mark-recapture efforts revealed a striking pattern of female-biased longevity in the painted turtle (<i>Chrysemys picta</i>), a species with temperature-dependent sex determination. As a result, this species provides a compelling system to examine the mechanisms of sex-specific aging in the absence of sex chromosomes. Here, we characterize sex- and age-associated patterns in the blood transcriptomes of wild painted turtles (n = 93). We identifbioRxiv : the preprint server for biology2025.11.26.690843https://www.ebi.ac.uk/biostudies/studies/S-EPMC12687789biostudies-literatureWidespread sex-biased gene expression reflects female-biased longevity in a species with environmental sex determination.PMC12687789IOS-1257857R01AG049416R01 AG049416DBI-2213824Adorsoo MJanzen FJHoekstra LABronikowski AMHagerty KSchmidt RESingh RBock SLJudson JfalseWidespread sex-biased gene expression reflects female-biased longevity in a species with environmental sex determination.Sexes frequently differ in life history traits including body size, lifespan, and age at sexual maturity. Aging, the progressive decline in physiological function and cellular resilience over time, is a central process contributing to sex-specific life histories, yet the mechanisms driving sex differences in aging remain largely unresolved. Long-term mark-recapture efforts revealed a striking pattern of female-biased longevity in the painted turtle (<i>Chrysemys picta</i>), a species with temperature-dependent sex determination. As a result, this species provides a compelling system to examine the mechanisms of sex-specific aging in the absence of sex chromosomes. Here, we characterize sex- and age-associated patterns in the blood transcriptomes of wild painted turtles (n = 93). We identif2025-01-01T00:00:00Z2025 Dec2026-06-03T03:16:33.218Z2026-06-03T03:10:48.122ZS-EPMC126877894137751010.1101/2025.11.26.690843