title: Genomewide analysis indicates that queen larvae have lower methylation levels in the honey bee (Apis mellifera).
abstract: The honey bee is a social insect characterized by caste differentiation, by which a young larva can develop into either a queen or a worker. Despite possessing the same genome, queen and workers display marked differences in reproductive capacity, physiology, and behavior. Recent studies have shown that DNA methylation plays important roles in caste differentiation. To further explore the roles of DNA methylation in this process, we analyzed DNA methylome profiles of both queen larvae (QL) and worker larvae (WL) of different ages (2, 4, and 6 day old), by using methylated DNA immunoprecipitation-sequencing (meDIP-seq) technique. The global DNA methylation levels varied between the larvae of two castes. DNA methylation increased from 2-day- to 4-day-old QL and then decreased in 6-day-old larvae. In WL, methylation levels increased with age. The methylcytosines in both larvae were enriched in introns, followed by coding sequence (CDS) regions, CpG islands, 2 kbp downstream and upstream of genes, and 5' and 3' untranslated regions (UTRs). The number of differentially methylated genes (DMGs) in 2-, 4-, and 6-day-old QL and WL was 725, 3,013, and 5,049, respectively. Compared to 4- and 6-day-old WL, a large number of genes in QL were downmethylated, which were involved in many processes including development, reproduction, and metabolic regulation. In addition, some DMGs were concerned with caste differentiation.
authors.affiliation: Honeybee Research Institute, Jiangxi Agricultural University, Nanchang, 330045, People's Republic of China.
authors.forename: Yuan Yuan
authors.initials: YY
authors.lastname: Shi
authors.forename: Wei Yu
authors.initials: WY
authors.lastname: Yan
authors.forename: Zachary Y
authors.initials: ZY
authors.lastname: Huang
authors.forename: Zi Long
authors.initials: ZL
authors.lastname: Wang
authors.forename: Xiao Bo
authors.initials: XB
authors.lastname: Wu
authors.forename: Zhi Jiang
authors.initials: ZJ
authors.lastname: Zeng
mesh_terms: D000818:Animals; D001516:Bees / Q000235:genetics* / Q000378:metabolism*; D019175:DNA Methylation; D005260:Female; D049750:Genome, Insect / Q000235:genetics*; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D007814:Larva / Q000235:genetics / Q000378:metabolism
chemical_list: D019476:Insect Proteins