Identification of QTL for aging in honey bee workers

Honey bees, Apis mellifera (L), are an excellent model organism for studying aging because they exhibit diverse social roles and a pronounced plasticity in aging rates. The aging rate of workers strongly depends on their social function but the underlying mechanisms are poorly understood, although vitellogenin has been identified as one possible candidate. Quantitative trait locus (QTL) mapping has been employed in several model organisms to understand the natural genetic architecture of longevity and identify potential candidate genes as regulators of aging. To identify genes that influence longevity in honey bees we have set up two crosses between artificially selected strains and sampled bees at a young and old age to identify allelic shifts with age. Using 40 bees per backcross, we initially screened the genome with 280 SNP markers. 92 and 96 markers were polymorphic in the two backcrosses, respectively. Based on these results we selected eight genomic regions to genotype in the entire cross. In addition, we genotyped markers for 7 previously mapped QTL for social behavior that may influence lifespan because they affect foraging behavior and ovary size, and have been linked to vitellogenin and insulin-like signaling. Our results will shed light on the linkage between social behavior and life-history, including aging in honey bees and identify QTL for longevity in honey bee workers. In general, our study will contribute to the mechanistic understanding of aging processes in a general life history context.