Project description:The molecular basis of evolutionary change is assumed to be genetic variation. However, growing evidence suggests that epigenetic mechanisms, such as DNA methylation, may also be involved in evolutionary change. An important first step in evaluating this hypothesis is to test for the presence of epigenetic variation between natural populations living under different environmental conditions. In the current study we explored variation between populations of Darwin’s finches living in adjacent “urban” and “rural” environments on Santa Cruz Island in the Galápagos. We tested for morphological, genetic, and epigenetic differences between the urban and rural populations of each of two species of ground finches, Geospiza fortis and G. fuliginosa. Using data collected from more than 1000 birds, we found significant morphological differences between populations of G. fortis, but not G. fuliginosa. We did not find genetic differences between populations of either species, based on comparisons of copy number variation (CNV). In contrast, we did find epigenetic differences between the urban and rural populations of both species, based on DNA methylation analysis. We explored genomic features and gene associations of the differentially methylated regions (DMR), as well as their possible functional significance. In summary, our study documents local population epigenetic variation within species of Darwin’s finches.
Project description:To reveal the correlation between epigenomic diversity and genomic SNVs, we first identified SNPs between T4 with other eleven Trichinella species. In total, we obtained 5,395,250 common SNVs across the twelve Trichinella species.
Project description:Expression profiling analyses for 5 maize inbreds and 4 hybrids, chosen to represent diversity in genotypes and heterosis responses, revealed a correlation between genetic diversity and transcriptional variation. This is a companion dataset to an Affymetrix profiling experiment (GEO Series GSE10236). Keywords: Genotype comparison series
2008-02-22 | GSE10542 | GEO
Project description:Genetic diversity for 3 bat species
Project description:Phenotypic plasticity and local adaptation via genetic change are two major mechanisms of response to dynamic environmental conditions. These mechanisms are not mutually exclusive, since genetic change can establish similar phenotypes to plasticity. This connection between both mechanisms raises the question of how much of the variation observed between species or populations is plastic and how much of it is genetic. In this study, we used a structured population of fire salamanders (Salamandra salamandra), in which two subpopulations differ in terms of physiology, genetics, mate-, and habitat preferences. Our goal was to identify candidate genes for differential habitat adaptation in this system, and to explore the degree of plasticity compared to local adaptation. We therefore performed a reciprocal transfer experiment of stream- and pond-originated salamander larvae and analyzed changes in morphology and transcriptomic profile (using species-specific microarrays). We observed that stream- and pond-originated individuals diverge in morphology and gene expression. For instance, pond-originated larvae have larger gills, likely to cope with oxygen-poor ponds. When transferred to streams, pond-originated larvae showed a high degree of plasticity, resembling the morphology and gene expression of stream-originated larvae (reversion); however the same was not found for stream-originated larvae when transferred to ponds, where the expression of genes related to reduction-oxidation processes was increased, possibly to cope with environmental stress. The lack of symmetrical responses between transplanted animals highlights the fact that the adaptations are not fully plastic and that some level of local adaptation has already occurred in this population. This study illuminates the process by which phenotypic plasticity allows local adaptation to new environments and its potential role in the pathway of incipient speciation.
Project description:H2A.B is a unique histone H2A variant that shares only 40 ~ 50 % sequence identity with canonical H2A. It has only been identified in mammals and has quickly evolved with remarkable sequence diversity among different species. H2A.B is ubiquitously expressed in most cells and tissues. It is mainly deposited in gene body region. The localization of H2A.B is associated with methylated CpG islands in mouse ES cells. H2A.B facilitates transcription elongation to go through methylated CpG islands in the gene bodies. One typical example is that H2A.B regulates transcription elongation at imprinted loci. We found H2A.B enriched in some methylated loci. Using ChIP-seq and MeDIP-seq, we test the correlation of H2A.B and DNA methylation.
Project description:Expression profiling analyses for 5 maize inbreds and 4 hybrids, chosen to represent diversity in genotypes and heterosis responses, revealed a correlation between genetic diversity and transcriptional variation. This is a companion dataset to an Affymetrix profiling experiment (GEO Series GSE10236). Keywords: Genotype comparison series Expression profiling was used to study gene expression in aerial tissue from 11-day seedlings of maize. Three biological replicates were performed for nine different genotypes; B37, B73, B84, Mo17, Oh43, B37xB73, B84xB73, Oh43xB73 and Oh43xMo17.
Project description:Epigenetic variation has the potential to control environmentally dependent development and contribute to phenotypic responses to local environments. Environmental epigenetic studies of sexual organisms confirm the responsiveness of epigenetic variation, which should be even more important when genetic variation is lacking. A previous study of an asexual snail, Potamopyrgus antipodarum, demonstrated that different populations derived from a single clonal lineage differed in both shell phenotype and methylation signature when comparing lake versus river populations. Here, we examine methylation variation among lakes that differ in environmental disturbance and pollution histories. The differential DNA methylation regions (DMRs) identified among the different lake comparisons suggested a higher number of DMRs and variation between rural Lake 1 and one urban Lake 2 and between the two urban Lakes 2 and 3, but limited variation between the rural Lake 1 and urban Lake 3. DMR genomic characteristics and gene associations were investigated. Observations suggest there is no effect of geographic distance or any consistent pattern of DMRs between urban and rural lakes. Environmental factors may influence epigenetic response.