Project description:eQTL mapping in a F1 diversity panel generated from 111 A.thaliana natural accessions 57 F1 lines without replicates, the 5th or 6th true leaf
Project description:Heterosis occurs where F1 offspring display superior characteristics to the parents. Heterosis is usually considered to result from crosses of genetically distinct (e.g. homozygous inbred) parents producing heterozygous F1 offspring. Most mechanistic models for heterosis require genetically heterozygous F1 hybrid offspring harbouring allelic diversity. Epigenetic or dosage models for heterosis could allow for heterosis effects in F1 offspring that display no allelic diversity with their parents. Reciprocal inter-ploidy crosses between diploid (2x) and tetraploid (4x) lines in the same genetic background generates genetically identical F1 triploids (3x). Such reciprocal F1 triploids differ according to whether the additional chromosome set is either maternally (maternal excess) or paternally inherited (paternal excess). Biomass accumulation and abiotic stress tolerance between the parental (2x and 4x) and reciprocal F1 triploid (3x) offspring of Arabidopsis thaliana accession C24 reveals a strong parental genome-dosage induced heterosis in the paternal-excess triploid F1 plants. In these F1 triploids, the circadian clock related genes CCA1 and TOC1, and the growth factors PIF4 and PIF5, display different expression levels compared to the non-heterotic maternal excess F1 triploid siblings. Whole transcriptome profiling reveals a paternal genome dosage effect on gene expression levels with strong enrichment for dysregulated abiotic stress-related genes in the paternal excess F1 triploids. This study demonstrates that heterosis can be triggered without allelic diversity in F1 triploid plants. Heterosis without heterozygosity in plants can be induced via an epigenetic “chromosome imprinting” like parental genome dosage effect requiring paternal transmission of an additional chromosome set
Project description:Expression level polymorphisms (ELPs) often result in cis-acting expression quantitative trait loci (cis-eQTL), which are important QTL and association mapping tools and account significantly for phenotypic variability. Generally, it is assumed that such stably heritable ELP represent regulatory element polymorphisms in the respective genes. However, comprehensive genome-wide analyses linking expression level, regulatory sequence and gene structure variation are missing, preventing definite verification of this assumption. Here we analyzed heritability of ELP observed between Arabidopsis thaliana accessions Eil-0 and Lc-0 by comparing genotyped recombinant inbred lines (RIL) to their parents in microarray analyses. Keywords: expression level polymorphism, Arabidopsis thaliana accessions, recombinant inbred lines
Project description:Heterosis occurs where F1 offspring display superior characteristics to the parents. Heterosis is usually considered to result from crosses of genetically distinct (e.g. homozygous inbred) parents producing heterozygous F1 offspring. Most mechanistic models for heterosis require genetically heterozygous F1 hybrid offspring harbouring allelic diversity. Epigenetic or dosage models for heterosis could allow for heterosis effects in F1 offspring that display no allelic diversity with their parents. Reciprocal inter-ploidy crosses between diploid (2x) and tetraploid (4x) lines in the same genetic background generates genetically identical F1 triploids (3x). Such reciprocal F1 triploids differ according to whether the additional chromosome set is either maternally (maternal excess) or paternally inherited (paternal excess). Biomass accumulation and abiotic stress tolerance between the parental (2x and 4x) and reciprocal F1 triploid (3x) offspring of Arabidopsis thaliana accession C24 reveals a strong parental genome-dosage induced heterosis in the paternal-excess triploid F1 plants. In these F1 triploids, the circadian clock related genes CCA1 and TOC1, and the growth factors PIF4 and PIF5, display different expression levels compared to the non-heterotic maternal excess F1 triploid siblings. Whole transcriptome profiling reveals a paternal genome dosage effect on gene expression levels with strong enrichment for dysregulated abiotic stress-related genes in the paternal excess F1 triploids. This study demonstrates that heterosis can be triggered without allelic diversity in F1 triploid plants. Heterosis without heterozygosity in plants can be induced via an epigenetic “chromosome imprinting” like parental genome dosage effect requiring paternal transmission of an additional chromosome set 4 or 5 biological replicates per ploidy level, each replicate being a single two weeks old seedling
Project description:The aim of this study was to analyze the impact of autotetraploidy on gene expression in Arabidopsis thaliana by comparing diploid versus tetraploid transcriptomes. In particular, this included the comparison of the transcriptome of different tetraploid A. thaliana ecotypes (Col-0 vs. Ler-0). The study was extended to address further aspects. One was the comparison of the transcriptomes in subsequent generations. This intended to obtain information on the genome wide stability of autotetraploid gene expression. Another line of work compared the transcriptomes of different diploid vs. tetraploid tissues. This aimed to investigate whether particular gene groups are specifically affected during the development of A. thaliana autotetraploids. Samples 1-8: Arabidopsis thaliana Col-0 tetraploid transcriptome. Transcriptional profiling and comparison of diploid vs. tetraploid Col-0 seedlings. The experiment was carried out with pedigree of independently generated and assessed tetraploid Col-0 lines. Samples 9-12: Arabidopsis thaliana Ler-0 tetraploid transcriptome. Transcriptional profiling and comparison of diploid vs. tetraploid Ler-0 seedlings. The experiment was carried out with pedigree of independently generated and assessed tetraploid Ler-0 lines. Samples 13-24: Arabidopsis thaliana Col-0 tetraploid transcriptome. Transcriptional profiling and comparison of diploid vs. tetraploid Col-0 leaves (6th - 8th). The experiment was carried out with pedigree of independently generated and assessed tetraploid Col-0 lines. Samples 25-32: Arabidopsis thaliana Ler-0 tetraploid transcriptome. Transcriptional profiling and comparison of diploid vs. tetraploid Ler-0 leaves (6th - 8th). The experiment was carried out with pedigree of independently generated and assessed tetraploid Ler-0 lines. Samples 33-36: Arabidopsis thaliana Ler-0 tetraploid transcriptome. Transcriptional profiling and comparison of tetraploid vs. tetraploid Ler-0 seedlings from the second (F2) and third (F3) generation after induction, respectively. The experiment was carried out with pedigree of independently generated and assessed tetraploid Ler-0 lines. Samples 37-40: Arabidopsis thaliana Col-0 tetraploid transcriptome. Transcriptional profiling and comparison of tetraploid vs. tetraploid Col-0 seedlings from the second (F2) and third (F3) generation after induction, respectively. The experiment was carried out with pedigree of independently generated and assessed tetraploid Col-0 lines. Samples 41-44: Arabidopsis thaliana Col-0/Ler-0 diploid transcriptome. Transcriptional profiling and comparison of diploid Col-0 vs. diploid Ler-0 seedlings. The experiment was carried out with pedigree of esrablished lines. Samples 45-48: Arabidopsis thaliana Col-0/Ler-0 tetraploid transcriptome. Transcriptional profiling and comparison of tetraploid Col-0 vs tetraploid Ler-0 seedlings. The experiment was carried out with pedigree of independently generated and assessed tetraploid Col-0 and Ler-0 lines.
Project description:In this study, we describe the impact of genetic variation on transcript abundance in an F2 population of Arabidopsis thaliana. The RNA-seq resource generated by this study is suitable for expression quantitative trait locus (eQTL) mapping. From the aligned RNA-seq reads, and available genomic data for each of the parents of the cross, we imputed the genomes of each F2 individual (to allow genetic mapping of RNA abundance traits; briefly, genetic differences in aligned RNA-seq reads were used to impute each F2 genome). Our results show that heritable differences on gene expression can be detected using F2 populations (that is, single F2 plants), and shed light on the control of expression differences among strains of this reference plant.
Project description:Small RNA diversity and function has been widely characterized in various tissues of the sporophytic generation of the angiosperm model Arabidopsis thaliana. In contrast, there is limited knowledge about small RNA diversity and their roles in developing male gametophytes. We thus carried out small RNA sequencing on RNA isolated from four stages of developing Arabidopsis thaliana pollen.
Project description:We have sequenced messenger RNA isolated from seedling tissue for 19 accessions of Arabidopsis thaliana (with biological replication). The 19 accessions for which RNA-Seq reads were collected have served as the founders for the MAGIC lines, a high-resolution recombinant inbred line mapping resource. RNA sequencing data was used to examine differential gene expression among the accessions.