A central question in biology is how does ecology and environment shape development, physiology and behavior of an organism. The blind Mexican cavefish has emerged as a powerful model to address this question. The species comes in two forms: an eyed, ancestral form, and at least 29 independently evolved cave-dwelling forms. This species is unique among model systems for addressing questions in evolutionary biology, but the lack of genetic tools in this model has limited its use in identifying genetic and molecular mechanisms underlying the evolution of complex traits. The experiments in this project will establish a broad genetic toolkit in the blind Mexican cavefish and surface conspecifics. The tools generated in this proposal will allow for the manipulation of genes in precise tissues, and a swapping of genes between ancestral surface fish and evolved cave-dwelling animals. The project will build on an established outreach program to bring the research to the broader public. The project will establish a set of K-12 training plans utilizing the cavefish to teach various topics in evolution to primary and secondary school children. Second, the project will establish a podcast entitled, the Research Diaries. The Research Diaries recently completed its first season, and season two will focus on non-model systems. Third, in order to bring the tools generated to the broader public, and in order to facilitate as many non-model systems as possible, the project will generate an annual workshop for non-model systems, were researchers can come to the PI's lab and work with the developed reagents.
Genetic tools in model systems have revolutionized biology, and has provided unparalleled insight into biological principles. However, the relatively few numbers of genetically amendable organisms provides a limited view of the diversity and complexity of biological processes. This project will develop transgenic and gene-targeted approaches for an emerging system in evolutionary biology, the blind Mexican cavefish, Astyanax mexicanus. A. mexicanus comes in two distinct forms: an ancestral eyed form, and at least 29 populations of evolved cave-dwelling fish. The project will first generate tissue specific Gal4 lines, and corresponding UAS effector lines for manipulating gene function in precise tissues. The project will focus on several tissues relevant to cavefish programs including neuronal, eye, and liver tissues. The project will also generate tamoxifen inducible Gal4 lines. Next, the project will generate lines with site-specific attP site, and the project will use these lines to integrate promoter regions in surface and cave forms. Finally, the project will develop CRISPR/Cas9 technologies in these fish, and will devise strategies for swapping genes between surface fish and cavefish. Taken together, these experiments will not only establish genetic tools in this non-model system, but will also establish methods for determining genotype-phenotype interactions and the molecular basis for complex traits.
This award was co-funded by the EDGE program and the Behavioral Systems Cluster in the Division of Integrative Organismal Systems and the Evolutionary Processes Cluster in the Division of Environmental Biology.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.