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:Transcriptome of cave and surface fish in teleost genus Sinocyclocheilus.
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.
Project description:In this pioneering study, we present the first comprehensive catalog of 683 small non-coding miRNAs for Astyanax mexicanus. Focusing on an early developmental stage, miRNAs were extracted and sequenced from 24hpf embryos of surface fish and three distinct cavefish morphs (Pachón, Tinaja, and Molino). We utilized in silico analyses to predict putative 3’UTR targets of these miRNAs, revealing a unique and extensive miRNA landscape in cavefish. Small RNA sequencing identified over 100 differentially expressed miRNAs in each cave morph compared to surface fish at 24hpf, suggesting early activation of miRNA-mediated silencing pathways. Notably, a subset of miRNAs was common across all three cave morphs, constituting cave-specific miRNAs potentially instrumental in cave adaptation. To unravel the functional implications of these cave-specific miRNAs, we analyzed their predicted target genes. Gene Ontology (GO) term analysis unveiled pathways which align with known adaptations in cavefish, primarily affecting development and metabolism. Further, cross-validating with a sample mRNAseq data from Pachón and surface fish also strongly suggested impact of these miRNAs on cave adaptation associated pathways. This study establishes a foundation for exploring miRNA-mediated gene regulation in cavefish, shedding light on their potential role in regulating early developmental and metabolic adaptations crucial for troglomorphic features. The comprehensive miRNA catalog provided will also guide future investigations into the intricate world of miRNA-mediated evolution in cave-adapted species.
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.
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: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.