Project description:Liver-derived cells from the surface and cave-adapted morphs of Astyanax mexicanus are valuable in vitro resources to explore the metabolism of these unique fish. However, 2D cultures have not yet fully mimicked the metabolic profile of the fish liver. Also, 3D culturing can modulate the transcriptomic profile of cells when compared to its 2D counterpart. Hence, to widen the range of metabolic pathways that can be depicted in vitro, we cultured the liver-derived SFL and CFL into 3D spheroids. We 3D cultured the cells at various cell seeding densities for 4 weeks and characterized the resultant transcriptome. The 3D cultured SFL and CFL cells indeed depicted a wider range of metabolic pathways as compared to the 2D culture. Further, the 3D spheroids also showed surface and cave-specific responses, making the spheroids an exciting system to study cave adaptation. Taken together, SFL and CFL spheroids prove to be a promising model for overall understanding of altered metabolism in Astyanax mexicanus.
Project description:Organisms adapt to and survive in environments with varying nutrient availability. Cis-regulatory changes play important roles in adaptation and phenotypic evolution. To what extent cis-regulatory elements contribute to metabolic adaptation is less understood. Here we have utilized a unique vertebrate model, Astyanax mexicanus, that survives in nutrient rich surface and nutrient deprived cave water to uncover gene regulatory networks in metabolic adaptation. We performed genome-wide analysis of accessible chromatin and histone modifications in the liver tissue of one surface and two independently derived cave populations, providing the first genome-wide epigenetic landscape in this organism. In parallel, we performed RNA Seq as a read out of gene expression. We find that many cis-regulatory elements differ between surface and the cavefish, while the two independently derived cave populations have evolved remarkably similar regulatory signatures. Changes in gene regulatory networks between the surface and cave morphotypes point to global changes in key metabolic pathways.
