Project description:For microbial cells, an appropriate response to changing environmental conditions is critical for viability. Transcription regulatory proteins, or transcription factors (TFs) sense environmental signals to change gene expression. However, it remains unclear how TFs and their corresponding gene regulatory networks are selected for over evolutionary time scales. The function of TFs and how they evolve are particularly understudied in archaeal organisms. Here we identified, characterized, and compared the function of the RosR transcription factor across three related species of hypersaline adapted model archaea. RosR was previously characterized as a global regulator of gene expression during oxidative stress in the species Halobacterium salinarum (HsRosR). Here we use functional genomics and quantitative phenotyping to demonstrate that, despite strong conservation of HsRosR across species, its function diverges substantially. Surprisingly, RosR in Haloferax volcanii and Haloferax mediterranei regulates genes whose products function in motility and the outer membrane, leading to significant defects in motility when rosR is deleted. Given weak conservation and degeneration in the RosR cis-regulatory sequence across species, we hypothesize that the RosR regulatory network is easily rewired during evolution across related species of archaea.
2024-11-20 | GSE279075 | GEO
Project description:Population genomics of Phengaris alcon/rebeli
Project description:Orangutans are an endangered species whose natural habitats are restricted to the Southeast Asian islands of Borneo and Sumatra. For potential species conservation and functional genomics studies, we derived induced pluripotent stem cells (iPSCs) from cryopreserved skin fibroblasts obtained from captive orangutans. We report the gene expression profiles of iPSCs and skin fibroblasts derived from orangtuans.
Project description:The function of a gene is closely connected to its expression specificity across tissues and cell types. RNA-Seq is a powerful quantitative tool to explore genome wide expression. The aim of the present study is to provide a comprehensive RNA-Seq dataset across the same 13 tissues for mouse and rat, two of the most relevant species for biomedical research. The dataset provides the transcriptome across tissues from three male C57BL6 mice and three male Han Wistar rats. We also describe our bioinformatics pipeline to process and technically validate the data. Principal component analysis shows that tissue samples from both species cluster similarly. By comparative genomics we show that many genes with high sequence identity with respect to their human orthologues have also a highly correlated tissue distribution profile and are in agreement with manually curated literature data for human. These results make us confident that the present study provides a unique resource for comparative genomics and will facilitate the analysis of tissue specificity and cross-species conservation in higher organisms.
Project description:For microbial cells, an appropriate response to changing environmental conditions is critical for viability. Transcription regulatory proteins, or transcription factors (TFs) sense environmental signals to change gene expression. However, it remains unclear how TFs and their corresponding gene regulatory networks are selected for over evolutionary time scales. The function of TFs and how they evolve are particularly understudied in archaeal organisms. Here we identified, characterized, and compared the function of the RosR transcription factor across three related species of hypersaline adapted model archaea. RosR was previously characterized as a global regulator of gene expression during oxidative stress in the species Halobacterium salinarum (HsRosR). Here we use functional genomics and quantitative phenotyping to demonstrate that, despite strong conservation of HsRosR across species, its function diverges substantially. Surprisingly, RosR in Haloferax volcanii and Haloferax mediterranei regulates genes whose products function in motility and the outer membrane, leading to significant defects in motility when rosR is deleted. Given weak conservation and degeneration in the RosR cis-regulatory sequence across species, we hypothesize that the RosR regulatory network is easily rewired during evolution across related species of archaea.
Project description:The nematode Caenorhabditis elegans contains each of the broad classes of eukaryotic small RNAs, including microRNAs (miRNAs), endogenous small-interfering RNAs (endo-siRNAs) and piwi-interacting RNAs (piRNAs). To better understand the evolution of these regulatory RNAs, we deep sequenced small RNAs from C. elegans and three closely related nematodes: C. briggsae, C. remanei and C. brenneri. The results reveal a fluid landscape of small RNA pathways with essentially no conservation of individual sequences aside from a subset of miRNAs. We identified 52 miRNA families that are conserved in each of the four species as well as numerous miRNAs that are species specific or shared between only two or three species. Despite a lack of conservation of individual piRNAs and siRNAs many of the features of each pathway, including genomic distribution, are conserved. We show that in each species, 26G siRNAs trigger stage-specific secondary siRNA formation. We also observe that piRNAs trigger siRNA formation from targets containing up to three mismatches in each species. Finally, we show that nematodes produce two distinct sex-specific classes of piRNAs, suggesting different roles for piRNAs in male and female germlines.
Project description:This SuperSeries is composed of the following subset Series: GSE19111: Conservation genomics of Atlantic salmon (Year One) GSE19119: Conservation genomics of Atlantic salmon (Year Two) Refer to individual Series