Deep evolutionary conservation of autism-related genes

E.O. Wilson proposed in Sociobiology that similarities between human and animal societies reflect common mechanistic and evolutionary roots. When introduced in 1975 this controversial hypothesis was beyond science's ability to test and remains unproven. We used genomic analyses to determine whether superficial behavioral similarities in humans and the highly social honey bee reflect common molecular mechanisms. Here we report that gene expression signatures for individual bees unresponsive to various salient social stimuli are significantly enriched for autism spectrum disorder-related genes. These signatures occur in the mushroom bodies, a high-level integration center of the insect brain. Further, our finding of enrichment was unique to autism spectrum disorders; brain gene expression signatures from other honey bee behaviors do not show this enrichment, nor do data sets from other human behavioral and health conditions. These results demonstrate deep conservation for genes associated with a human social pathology and individual differences in insect social behavior, thus providing an example of how comparative genomics can be used to test sociobiological theory. Overall design: In this experiment, we sequenced a total of 36 mushroom body samples. Seven-day-old worker bees from two single-drone-inseminated (SDI) colonies were chosen for sequencing From each colony, we sequenced the whole transcriptome from the mushroom body of six worker bees from each of three different behavioural types: nurses, guards, and unresponsive bees. Thus, a total of 12 mushroom body samples for each behavioural type and a total of 18 samples from each colony were sequenced.