Allele-specific expression between Arabidopsis genus
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ABSTRACT: We analyzed allele-specific expression (ASE) in leaf and floral tissues of F1 interspecific hybrids generated between the two closely related species of Arabidopsis thaliana and Arabidopsis lyrata with a whole-genome SNP tiling array (AtSNPtile1). 24 sampes, 12 DNA samples from parents and hybrids, 12 RNA sample from leaf and flowers of hybrids
ORGANISM(S): Arabidopsis thaliana x Arabidopsis lyrata
Project description:We analyzed allele-specific expression (ASE) in leaf and floral tissues of F1 interspecific hybrids generated between the two closely related species of Arabidopsis thaliana and Arabidopsis lyrata with a whole-genome SNP tiling array (AtSNPtile1).
Project description:We compared the expression between inter-specific hybrids (A. thaliana-A. lyrata, A. thaliana-A. halleri) and mid parent values of their parental lines. Mature leaves in A. thaliana (Col), A. lyrata ssp. lyrata, A. halleri ssp. gemmifera and interspecific hybrid between A. thaliana and A. lyrata and between A. thaliana and A. halleri
Project description:We compared the expression between inter-specific hybrids (A. thaliana-A. lyrata, A. thaliana-A. halleri) and mid parent values of their parental lines.
Project description:Small RNA sequences from Arabidopsis lyrata leaves, as isolated from a single sample of rosette leaf tissue. These data were analyzed to 1) examine microRNA processing accuracy in A. lyrata and 2) to examine patterns of 24nt siRNA accumulation in A. lyrata.
Project description:We generated F1 hybrids of each of the sister species A. halleri and A. lyrata with their outgroup relative of A. thaliana and monitored allele-specific levels of expression in standard growth conditions, in response to dehydration or cold exposure. This data allowed us to map the genome-wide distribution of cis-regulatory mutations active in three distinct environments reflecting divergent adaptations of the two species. Because the sister species were both crossed to an outgroup species, it was possible to assign a phylogenetic origin to cis-acting mutations. Cis-acting mutations observed in only one of the two hybrids were likely to be derived, whereas those observed in both hybrids either predate predated the split between the two species or arose along the A. thaliana lineage. By contrasting the distribution of cis-regulatory mutations derived in the A. halleri to those derived on the A. lyrata lineage, we could establish relative rates of cis-acting evolution across polygenic molecular functions and detect lineage-specific polygenic adaptation to environmental challenges.
Project description:We generated F1 hybrids of each of the sister species A. halleri and A. lyrata with their outgroup relative of A. thaliana and monitored allele-specific levels of expression in standard growth conditions, in response to dehydration or cold exposure. This data allowed us to map the genome-wide distribution of cis-regulatory mutations active in three distinct environments reflecting divergent adaptations of the two species. Because the sister species were both crossed to an outgroup species, it was possible to assign a phylogenetic origin to cis-acting mutations. Cis-acting mutations observed in only one of the two hybrids were likely to be derived, whereas those observed in both hybrids either predate predated the split between the two species or arose along the A. thaliana lineage. By contrasting the distribution of cis-regulatory mutations derived in the A. halleri to those derived on the A. lyrata lineage, we could establish relative rates of cis-acting evolution across polygenic molecular functions and detect lineage-specific polygenic adaptation to environmental challenges. A.thalianaxA.lyrata under cold, dehydration and standard conditions, 3 biological replicates; A.thalianaxA.halleri under cold, dehydration and standard conditions, 3 biological replicates; toal 18 RNA-seq samples
Project description:Small RNA sequences from Arabidopsis lyrata leaves, as isolated from a single sample of rosette leaf tissue. These data were analyzed to 1) examine microRNA processing accuracy in A. lyrata and 2) to examine patterns of 24nt siRNA accumulation in A. lyrata. A single small RNA library from rosette leaf tissue was analyzed using an Illumina Genome Analyzer.
Project description:In plants, imprinted gene expression occurs in endosperm seed tissue and can be associated with differential DNA methylation between maternal and paternal alleles. Imprinting is theorized to have been selected for because of conflict between parental genomes in offspring, but most studies of imprinting have been conducted in Arabidopsis thaliana, an inbred primarily self-fertilizing species that should have limited parental conflict. We examined embryo and endosperm allele-specific expression and DNA methylation genome-wide in the wild outcrossing species Arabidopsis lyrata. Here we show that the majority of A. lyrata imprinted genes exhibit parentally-biased expression in A. thaliana, suggesting that there is evolutionary conservation in gene imprinting. Surprisingly, we discovered substantial interspecies differences in methylation features associated with paternally expressed imprinted genes (PEGs). Unlike A. thaliana, the maternal allele of many A. lyrata PEGs was hypermethylated in the CHG context. Increased maternal allele CHG methylation was associated with increased expression bias in favor of the paternal allele. We propose that CHG methylation maintains or reinforces repression of maternal alleles of PEGs. These data suggest that while the genes subject to imprinting are largely conserved, there is flexibility in the epigenetic mechanisms employed between closely related species to maintain monoallelic expression. This supports the idea that imprinting of specific genes is a functional phenomenon, and not simply a byproduct of seed epigenomic reprogramming.
Project description:Here, we produced a set of interspecific F1 triploid hybrid plants between Oryza sativa, ssp. japonica (2nâ=â2xâ=â24, genome AA) and the tetraploid form of O. punctata (2nâ=â4xâ=â48, genome, BBCC), and conducted RNA-seq transcriptome profiling of the hybrids and their exact parental plants. We analyzed both homeolog expression bias and overall gene expression level difference in the hybrids relative to the in silico âhybridsâ (parental mixtures). We found that approximately 16% (2,541) of the 16,112 expressed genes in leaf tissue of the F1 hybrids showed nonadditive expression, which were specifically enriched in photosynthesis-related pathways. Interestingly, changes in the maternal homeolog expression, including non-stochastic silencing, were the major causes for altered homeolog expression partitioning in the F1 hybrids. Our findings have provided further insights into the transcriptome response to interspecific hybridization and heterosis.
Project description:In plants, imprinted gene expression occurs in endosperm seed tissue and can be associated with differential DNA methylation between maternal and paternal alleles. Imprinting is theorized to have been selected for because of conflict between parental genomes in offspring, but most studies of imprinting have been conducted in Arabidopsis thaliana, an inbred primarily self-fertilizing species that should have limited parental conflict. We examined embryo and endosperm allele-specific expression and DNA methylation genome-wide in the wild outcrossing species Arabidopsis lyrata. Here we show that the majority of A. lyrata imprinted genes exhibit parentally-biased expression in A. thaliana, suggesting that there is evolutionary conservation in gene imprinting. Surprisingly, we discovered substantial interspecies differences in methylation features associated with paternally expressed imprinted genes (PEGs). Unlike A. thaliana, the maternal allele of many A. lyrata PEGs was hypermethylated in the CHG context. Increased maternal allele CHG methylation was associated with increased expression bias in favor of the paternal allele. We propose that CHG methylation maintains or reinforces repression of maternal alleles of PEGs. These data suggest that while the genes subject to imprinting are largely conserved, there is flexibility in the epigenetic mechanisms employed between closely related species to maintain monoallelic expression. This supports the idea that imprinting of specific genes is a functional phenomenon, and not simply a byproduct of seed epigenomic reprogramming. Examination of total gene expression, parent-of-origin specific allelic bias, or DNA methylation in embryo, endosperm, flower bud or seedcoat tissue from Arabidopsis lyrata accessions MN47 (MN), Karhumaki (Kar or KA), and crosses between them. High-throughput Illumina poly-A-selected mRNA-seq was used to identify imprinted genes in A. lyrata, and high-throughput Illumina whole genome bisulfite-sequencing was used to examine DNA methylation. mRNA-seq samples are designated MMxFF_T# where MM is the mother of the cross (either MN for MN47 or KA for Kar), FF is the father, T is the tissue (E for embryo, N for endosperm, S for seedcoat, b for buds), and # is the replicate numbers. Samples obtained from bisulfite sequencing follow the same naming but have suffix _BS and indicate cytosine methylation context (CpG, CHG, or CHH). For KAxMN bisulfite sequencing, additional files MMxFF_T#_BS_P_C.txt follow the same naming scheme but contain context-specific methylation data (C) from reads that mapped preferentially to one parent strain (P).