title: Epigenetic modifications and their relation to caste and sex determination and adult division of labor in the stingless bee Melipona scutellaris.
abstract: Stingless bees of the genus Melipona, have long been considered an enigmatic case among social insects for their mode of caste determination, where in addition to larval food type and quantity, the genotype also has a saying, as proposed over 50 years ago by Warwick E. Kerr. Several attempts have since tried to test his Mendelian two-loci/two-alleles segregation hypothesis, but only recently a single gene crucial for sex determination in bees was evidenced to be sex-specifically spliced and also caste-specifically expressed in a Melipona species. Since alternative splicing is frequently associated with epigenetic marks, and the epigenetic status plays a major role in setting the caste phenotype in the honey bee, we investigated here epigenetic chromatin modification in the stingless bee Melipona scutellaris. We used an ELISA-based methodology to quantify global methylation status and western blot assays to reveal histone modifications. The results evidenced DNA methylation/demethylation events in larvae and pupae, and significant differences in histone methylation and phosphorylation between newly emerged adult queens and workers. The epigenetic dynamics seen in this stingless bee species represent a new facet in the caste determination process in Melipona bees and suggest a possible mechanism that is likely to link a genotype component to the larval diet and adult social behavior of these bees.
authors.affiliation: Departamento de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil.|Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Carlos A M
authors.initials: CAM
authors.lastname: Cardoso-Júnior
authors.affiliation: Departamento de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil.
authors.forename: Patrícia Tieme
authors.initials: PT
authors.lastname: Fujimura
authors.affiliation: Departmento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, SP, Brazil.
authors.forename: Célio Dias
authors.initials: CD
authors.lastname: Santos-Júnior
authors.affiliation: Departamento de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil.
authors.forename: Naiara Araújo
authors.initials: NA
authors.lastname: Borges
authors.affiliation: Departamento de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil.
authors.forename: Carlos
authors.initials: C
authors.lastname: Ueira-Vieira
authors.affiliation: Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Klaus
authors.initials: K
authors.lastname: Hartfelder
authors.affiliation: Departamento de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil.
authors.forename: Luiz Ricardo
authors.initials: LR
authors.lastname: Goulart
authors.affiliation: Departamento de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil.
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Bonetti