Genomics and evolutionary studies on bees

Abstract

There are 20,061 bee species described in the World. They have an important role as pollinators of native plants and commercial crops. Bees have been studied for centuries and the species Apis mellifera and Bombus terrestris have gained prominence as important biological models. Although countless studies on bees have been published, several questions concerning general biology, behavior, physiology and evolution are still unsolved. The advent of new techniques, as Next Sequencing Generation, has enabling to revisit old questions as well as investigate new and intriguing ones. This project is organized into two main research lines: (1) Genomics and (2) Functional Genomics encompassing four projects. Genomics Project 1 will investigate the presence of NUMTS and heteroplasmy. These two phenomena have important consequences in phylogenetic, phylogeographic and genetic population studies. The species Bombus morio was elected for the heteroplasmy deep study due to previous data. Twenty-four species will be analyzed for NUMTS and their mitochondrial genome will be obtained. Genomics Project 2 purposes to obtain the complete nuclear genome of Tetrapedia diversipes. This species is an excellent model for diapause studies. The transcriptome has already been obtained but the lack of a reference genome unable to perform an accurate annotation. Also we intend to obtain the nuclear genome of Melipona bicolor, a eusocial bee species that presents polygyny behavior. This behavior has been studied at genomic level only in the ant Solenopsis invicta. These latter genomic projects are in agreement with a bee genomic initiative led by researches from USP/Ribeirão Preto. Functional Genomics Project 1 proposes comparisons at expression level between the subcastes nurse and forager of Tetragonisca angustula, eusocial bee, and Bombus terrestris, primitively eusocial. Also interspecific comparisons will be performed according to subcastes. The results will enable to infer the existence of conserved genes and their expression level underlying the subcastes behavior. Genomics Project 2 is an extension of current PhD project on evolution of social behavior. Candidate genes having differential expression profiles will be investigated in 10 bee species. These species were selected according to their phylogenetic position. The validation of these genes will be an indicative of a genetic toolkit related to social behavior. All these projects involve undergraduate and graduate students and one postdoc. (AU)