Abstract
DNA methylation has become a hallmark of the aging-relate genomic architecture in higher vertebrates. In invertebrates, however, the best studied aging models, the nematode worm Caenorhabditis elegans and the fruit fly Drosophila melanogaster, either do not have DNA methylation at all (C. elegans) or its role is still unclear and controversial. Since the honey bee, Apis mellifera, has a complete genetic toolkit for DNA methylation and methylation occurs at CpG dinucleotides of gene bodies, we decided to investigate the possible role of DNA methylation in this social insect. Furthermore, different from other metazoans, social insects, with the honey bee as a model organism, present a major disruption in the reproduction/longevity trade-off, making it an even more attractive model to study the epigenetics aspects of longevity and reproduction. Our hypothesis is that inactive state of the ovaries of workers (the facultative worker sterility) is contingent on the social condition of the hive, that is, the presence or absence of a dominant egg-laying queen, and that this social condition affects the ovary methylome and, implicitly the workers' reproduction/longevity trade-off. We recently obtained preliminary results showing that expression of the DNA methyltransferase (DNMT) genes is strongly up-regulated in inactive ovaries of workers kept in queen right colonies, and is similarly up-regulated in ovaries of workers kept in cages and exposed to synthetic queen mandibular gland pheromone. With this current project proposal, we expect to gain deep insights into the role of DNA methylation in molecular regulatory network underlying the reproduction/longevity trade-off in workers. (AU)
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