Project description:Deep Sequencing of mRNA from Drosophila melanogaster, Drosophila Sechellia, and their F1 hybrid. These data were generated in a study to analyze the extent and specificity of trans-splicing in Drosophila. mRNA-seq libraies were prepared from poly(A)+ RNA prepared from whole F1 hybrids of D. melanogaster and D. sechellia (female 0-3d post eclosion). Separate control libraries were prepared from D. melanogaster and D. sechellia total RNA (mixed before library preparation). The results of this study identified 80 novel trans-splicing events between homologous alleles of the same gene. Keywords: RNA-Seq Keywords: Expression profiling by high throughput sequencing There were 2 total samples in this study. Paired-end mRNA-seq was used to survey trans-splicing in F1 hybrids of D. melanogaster and D. sechellia. A mixed "control" library was used to assess the frequency of false-positive trans-splicing signal resulting from errors in reference genomes, high-throughput sequencing, and RT-PCR amplification based strand-switching.
Project description:Deep Sequencing of mRNA from Drosophila melanogaster, Drosophila Sechellia, and their F1 hybrid. These data were generated in a study to analyze the extent and specificity of trans-splicing in Drosophila. mRNA-seq libraies were prepared from poly(A)+ RNA prepared from whole F1 hybrids of D. melanogaster and D. sechellia (female 0-3d post eclosion). Separate control libraries were prepared from D. melanogaster and D. sechellia total RNA (mixed before library preparation). The results of this study identified 80 novel trans-splicing events between homologous alleles of the same gene. Keywords: RNA-Seq Keywords: Expression profiling by high throughput sequencing
Project description:We investigated the cis-regulatory divergences in alternative splicing and their relationship with tissue-dependent trans-regulation in multiple tissues of an F1 hybrid mouse. By obtaining more than 240 million read pairs on average in each sample from 5 organs and ESC as well as published data in liver, we comprehensively analyzed the allelic splicing patterns across tissues in hybrid mice. We find that tissue-dependent regulation causing large splicing differences is highly conserved and likely functional, while splicing divergence mainly affects genes under relaxed selective constraints. Although cis-divergence is in general associated with higher densities of sequence variants in regulatory regions, events with high usage of the dominant isoform could tolerate more mutations, which explains the paradoxical sequence conservation pattern in their exonic versus intronic splicing site flanking regions. Finally, we demonstrated that non-adaptive mutations are often masked in tissues where accurate splicing likely is more important, and experimentally attributed such buffering effect to trans-regulatory splicing efficiency.
Project description:These data were generated in a study to analyze the genetic causes of gene regulatory divergence. mRNA-seq libraies were prepared from poly(A)+ RNA prepared from whole F1 hybrids of D. melanogaster and D. sechellia (female 0-3d post eclosion, "D_mel_x_D_sec"). A mixed mRNA- seq library was prepared from D. melanogaster and D. sechellia poly(A) + RNA (mixed before library preparation, "D_mel_+_D_sec). Finally, separate mRNA-seq libraries were prepared from poly(A)+ RNA from each species ("D_mel" and "D_sec"). The results of this study showed that 78% of genes expressed in the two species are differentially expressed, and that cis- and trans-regulatory divergence affect 51% and 66% of expressed genes, respectively. Keywords: RNA-Seq
Project description:Gene-expression divergence between species shapes morphological evolution, but the molecular basis is largely unknown. Here we show cis- and trans-regulatory elements and chromatin modifications on gene-expression diversity in genetically tractable Arabidopsis allotetraploids. In Arabidopsis thaliana and Arabidopsis arenosa, both cis and trans with predominant cis-regulatory effects mediate gene-expression divergence. The majority of genes with both cis- and trans-effects are subjected to compensating interactions and stabilizing selection. Interestingly, chromatin modifications correlate with cis - and trans -regulation. In F1 allotetraploids, Arabidopsis arenosa trans factors predominately affect allelic expression divergence. Arabidopsis arenosa trans factors tend to upregulate Arabidopsis thaliana alleles, whereas Arabidopsis thaliana trans factors up- or down-regulate Arabidopsis arenosa alleles. In resynthesized and natural allotetraploids, trans effects drive expression of both homoeologous loci into the same direction. We provide evidence for natural selection and chromatin regulation in shaping gene-expression diversity during plant evolution and speciation. Examination of gene expression in 5 tetraploid Arabidopsis using mRNA-seq
Project description:Gene-expression divergence between species shapes morphological evolution, but the molecular basis is largely unknown. Here we show cis- and trans-regulatory elements and chromatin modifications on gene-expression diversity in genetically tractable Arabidopsis allotetraploids. In Arabidopsis thaliana and Arabidopsis arenosa, both cis and trans with predominant cis-regulatory effects mediate gene-expression divergence. The majority of genes with both cis- and trans-effects are subjected to compensating interactions and stabilizing selection. Interestingly, chromatin modifications correlate with cis - and trans -regulation. In F1 allotetraploids, Arabidopsis arenosa trans factors predominately affect allelic expression divergence. Arabidopsis arenosa trans factors tend to upregulate Arabidopsis thaliana alleles, whereas Arabidopsis thaliana trans factors up- or down-regulate Arabidopsis arenosa alleles. In resynthesized and natural allotetraploids, trans effects drive expression of both homoeologous loci into the same direction. We provide evidence for natural selection and chromatin regulation in shaping gene-expression diversity during plant evolution and speciation.
Project description:Gene regulation can evolve either by cis-acting local changes to regulatory element DNA sequences or by global changes to the trans-acting regulatory environment; however, the modes favored during recent human evolution are unknown. To date, studies investigating gene regulatory divergence between closely-related species have produced limited estimates on the relative contributions of cis and trans effects on DNA regulatory element activities at a global-scale. By leveraging a comparative ATAC-STARR-seq framework, we identified 10,779 regulatory regions with divergent activity in cis and 10,608 regulatory regions with divergent activity in trans between human and rhesus macaque lymphoblastoid cell lines (LCLs). This revealed substantially more trans effects than predicted and indicates trans-regulatory mechanisms play a larger role in human evolution than previously expected. We also discover that most species-specific regulatory elements (67%) diverge in both cis and trans, suggesting these two mechanisms jointly drive divergent regulatory activity in a single sequence.