Meeting Abstract
Plasticity, or the ability of a single genotype to produce multiple phenotypes under different environmental conditions, allows species to respond rapidly to changes in their environment. This response may even guide future evolution (i.e. via the flexible stem model). While it’s thought that plasticity itself can evolve, little is known about its genetic underpinnings. Many teleost lineages, including African cichlids, have diverged along a benthopelagic axis encompassing coordinated shifts among behavior, morphology, and ecological niche. Importantly, some species also exhibit significant plasticity along this axis; that is, fish presented with a primarily benthic diet will look significantly different from siblings presented with a primarily pelagic diet. Previous work in our lab utilizing a cross between species that differ in their ability to mount a plastic response has identified several candidate genes that underlie this phenomenon. Importantly, many of these genes may be manipulated in the zebrafish model system. In this study, we aim to first evaluate differences in bone deposition rates across wildtype zebrafish presented with alternate biting versus suction-feeding diet treatments. Using calcium-binding fluorochromes, we labelled bone at three time-points: four weeks before treatments began, at the beginning of diet treatments, and after four weeks of treatment. We compared rates of bone deposition both before and after treatments as well as across treatments in several ecologically relevant bones. Alternate modes of feeding resulted in marked changes in craniofacial geometry, as well as in rates of bone deposition. These results set an important foundation for future work wherein the experiments are repeated in genetically manipulated animals.
