Project description:we report a transcriptome-wide comparative investigation between surface and cave species in Sinocyclocheilus. De novo transcriptome assemblies were performed on surface and cave species; then the Sinocyclocheilus contigs were annotated with Gene Ontology. RNA-Seq assays revealed reduced transcription of a series of visual phototransduction and retinal disease related genes in cave-dwelling species compared with surface species. Degeneration of the retina in Sinocyclocheilus cavefish might occur in a lens-independent way by the down-regulation of several transcriptional factors, which have direct roles in retina development and maintenance, such as crx, rorb and Wnt pathway members. Examination of 2 different eye samples in 2 Sinocyclocheilus species.
Project description:we report a transcriptome-wide comparative investigation between surface and cave species in Sinocyclocheilus. De novo transcriptome assemblies were performed on surface and cave species; then the Sinocyclocheilus contigs were annotated with Gene Ontology. RNA-Seq assays revealed reduced transcription of a series of visual phototransduction and retinal disease related genes in cave-dwelling species compared with surface species. Degeneration of the retina in Sinocyclocheilus cavefish might occur in a lens-independent way by the down-regulation of several transcriptional factors, which have direct roles in retina development and maintenance, such as crx, rorb and Wnt pathway members.
2013-03-31 | GSE40446 | GEO
Project description:Sinocyclocheilus Cave fish
| PRJNA627321 | ENA
Project description:Transcriptome of cave and surface in Sinocyclocheilus
Project description:We found higher substitution rates in cavefish compared with surface fish, in accordance with a smaller cavefish population size which has allowed more rapid fixation of derived alleles present in the ancestral population. This result also implies that the Pachn cave population is much younger than previously estimated. The comparison of these data with simulations suggests that the Pachn cavefish population has probably been underground less than 30,000 years. This new time frame, together with other evidence, indicate that the evolution of cave phenotypes mainly involves the fixation of cryptic genetic variants present in surface fish populations within a short period of time.
Project description:Studying how different genotypes respond to environmental variation is essential to understand the genetic basis of adaptation. The Mexican tetra, Astyanax mexicanus, has cave and surface‐dwelling morphotypes that have adapted to entirely different environments in the wild, and are now successfully maintained in lab conditions. While this has enabled the identification of genetic adaptations underlying a variety of physiological processes, few studies have directly compared morphotypes between lab‐reared and natural populations. Such comparative approaches could help dissect the varying effects of environment and morphotype, and determine the extent to which phenomena observed in the lab are generalizable to conditions in the field. To this end, we take a transcriptomic approach to compare the Pachón cavefish and their surface fish counterparts in their natural habitats and the lab environment. We identify key changes in expression of genes implicated in metabolism and physiology between groups of fish, suggesting that morphotype (surface or cave) and environment (natural or lab) both alter gene expression. We find gene expression differences between cave and surface fish in their natural habitats are much larger than differences in expression between morphotypes in the lab environment. However, lab‐raised cave and surface fish still exhibit numerous gene expression changes, supporting genetically encoded changes in livers of this species. From this, we conclude that a controlled laboratory environment may serve as an ideal setting to study the genetic underpinnings of metabolic and physiological differences between the cavefish and surface fish.
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:Dysregulation of sleep has widespread health consequences and represents an enormous health burden. Short-sleeping individuals are predisposed to the effects of neurodegeneration, suggesting a critical role for sleep in the maintenance of neuronal health. While the effects of sleep on cellular function are not completely understood, growing evidence has identified an association between sleep loss and DNA damage, raising the possibility that sleep facilitates efficient DNA repair. The Mexican tetra fish, Astyanax mexicanus provides a model to investigate the evolutionary basis for changes in sleep and the consequences of sleep loss. Multiple cave-adapted populations of these fish have evolved to sleep for substantially less time compared to surface populations of the same species without identifiable impacts on healthspan or longevity. To investigate whether the evolved sleep loss is associated with DNA damage and aging, we compared the transcriptional response to aging between surface and cave morphs of A. 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. 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.
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. 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.