Project Details
Description
One of the central questions in biodiversity research is how did Life go from one to currently 1.8 million described species? For most animals, species are categorized as groups of individuals that interbreed with each other. Therefore, new animal species can arise by genetic mutations that ultimately prevent two groups from producing hybrid offspring. However, animal species may also change by acquiring differences in the millions of bacteria that typically live in symbiotic relationships inside them. This research addresses a major gap in our knowledge about how biodiversity arises: whether or not the symbiotic community of bacteria within a host species can contribute to hybrid lethality between species. To that end, the investigation will address three aims using several species of the model insect Nasonia that vary in their level of hybrid lethality: (i) Test the prediction that bacterial diversity is species-specific and abnormally reduced in hybrids that die (ii) Test the prediction that immunity genes are preferentially misexpressed in hybrids, and associate specific gene expression differences to the alterations in the hybrids' bacterial community (iii) Test if hybrid mortality is due to either a reduction in beneficial bacteria or an increase in pathogenic bacteria. The studies will integrate genetic, taxonomic, and functional dimensions of animal-microbe symbioses to comprehensively determine the consequences of bacterial symbionts on speciation in a model system. Taxonomically, the investigators will characterize new species of bacteria and existing species of bacteria in novel functions. Preliminary studies suggest 25% of the bacterial species in Nasonia are new to science. Genetic aspects of the studies will include the effects that hybridization can have on animal gene expression and the genetic diversity of their bacterial symbionts. Functionally, this work will unravel the host's dependence on bacterial symbionts throughout development, and test whether bacterial symbionts are as important as genes in the generation of new, animal species.
Broader impacts of this project include (i) the development of a new undergraduate course at Vanderbilt University that will involve students in the research, (ii) the creation of an online repository for taxonomic information on the symbionts discovered in this research, (iii) dissemination of data through publically accessible databases, and (iv) extensions to understanding speciation and symbiosis in new ways across all animals, including humans. Finally, the proposed research will provide training to one graduate student, one research assistant, and several undergraduates involved in volunteerships, internships, and research for credit.
Status | Finished |
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Effective start/end date | 3/1/11 → 2/28/17 |
Funding
- National Science Foundation: $1,270,109.00