A Queen Mary University of London-led team considers chromatin structure and its contributions to female caste phenotypes in the honey bee, Apis mellifera. The researchers used chromatin immunoprecipitation sequencing to map the distribution of H3K4me3, H3K27ac, and H3K36me3 histone marks across the genome in honey bee larvae heads at a stage where female bees are differentiating into sterile worker bees or queen bees.