title: MicroRNAs in Honey Bee Caste Determination.
abstract: The cellular mechanisms employed by some organisms to produce contrasting morphological and reproductive phenotypes from the same genome remains one of the key unresolved issues in biology. Honeybees (Apis mellifera) use differential feeding and a haplodiploid sex determination system to generate three distinct organismal outcomes from the same genome. Here we investigate the honeybee female and male caste-specific microRNA and transcriptomic molecular signatures during a critical time of larval development. Both previously undetected and novel miRNAs have been discovered, expanding the inventory of these genomic regulators in invertebrates. We show significant differences in the microRNA and transcriptional profiles of diploid females relative to haploid drone males as well as between reproductively distinct females (queens and workers). Queens and drones show gene enrichment in physio-metabolic pathways, whereas workers show enrichment in processes associated with neuronal development, cell signalling and caste biased structural differences. Interestingly, predicted miRNA targets are primarily associated with non-physio-metabolic genes, especially neuronal targets, suggesting a mechanistic disjunction from DNA methylation that regulates physio-metabolic processes. Accordingly, miRNA targets are under-represented in methylated genes. Our data show how a common set of genetic elements are differentially harnessed by an organism, which may provide the remarkable level of developmental flexibility required.
authors.affiliation: Research School of Biology, Australian National University, ACT, 0200, Australia.|Centre for Research in Therapeutic Solutions, Faculty of Education, Science, Technology and Mathematics, University of Canberra, ACT, 2617, Australia.
authors.forename: Regan
authors.initials: R
authors.lastname: Ashby
authors.affiliation: Research School of Biology, Australian National University, ACT, 0200, Australia.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Forêt
authors.affiliation: Research School of Biology, Australian National University, ACT, 0200, Australia.|School of Biological Sciences, University of Adelaide, SA, 5005, Australia.|School of Agriculture, Food and Wine,University of Adelaide, SA, 5005, Australia.|The University of Adelaide and Shanghai Jiao Tong University Joint International Laboratory for Agriculture and Health, University of Adelaide, SA, 5005, Australia.
authors.forename: Iain
authors.initials: I
authors.lastname: Searle
authors.affiliation: Research School of Biology, Australian National University, ACT, 0200, Australia.
authors.forename: Ryszard
authors.initials: R
authors.lastname: Maleszka
mesh_terms: D000818:Animals; D001516:Bees / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D016678:Genome; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D007814:Larva / Q000235:genetics / Q000378:metabolism; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D034622:RNA Interference; D019849:Sex Determination Processes; D059467:Transcriptome
chemical_list: D019476:Insect Proteins; D035683:MicroRNAs