Project description:Polyploidization and introgression are major events driving plant genome evolution and influencing crop breeding. However, the mechanisms underlying the higher-order chromatin organization of subgenomes and alien chromosomes are largely unknown. We probe the three-dimensional chromatin architecture of Aikang 58 (AK58), a widely-cultivated allohexaploid wheat variety carrying the 1RS/1BL translocation chromosome. The regions involved in inter-chromosomal interactions, both within and between subgenomes, have highly similar sequences. Subgenome-specific territories tend to be connected by subgenome-dominant homologous transposable elements (TEs). The alien 1RS chromosomal arm, which was introgressed from rye and differs from its wheat counterpart, has relatively few inter-chromosome interactions with wheat chromosomes. An analysis of local chromatin structures reveals topologically associating domain (TAD)-like regions covering 52% of the AK58 genome, the boundaries of which are enriched with active genes, zinc-finger factor-binding motifs, CHH methylation, and 24-nt small RNAs. The chromatin loops are mostly localized around TAD boundaries, and the number of gene loops is positively associated with gene activity. The present study reveals the impact of the genetic sequence context on the higher-order chromatin structure and subgenome stability in hexaploid wheat. Specifically, we characterized the sequence homology-mediated inter-chromosome interactions and the non-canonical role of subgenome-biased TEs. Our findings may have profound implications for future investigations of the interplay between genetic sequences and higher-order structures and their consequences on polyploid genome evolution and introgression-based breeding of crop plants.
2020-11-30 | GSE139020 | GEO
Project description:Transcriptome of rye, 1BL.1RS translocation and non-translocation under cold
Project description:Expression analysis of individual homoeologous wheat genome- and rye genome-specific transcripts in a 2BS.2RL wheat-rye translocation
| PRJNA253144 | ENA
Project description:Transcriptome of cold-acclimated 1BL.1RS wheat-rye translocation line and its near-isoline
Project description:To distinguish transcripts expressed from each of the three wheat genomes and those from the rye chromatins, genomic probes generated from diploid progenitors of wheat and rye were synthesized
Project description:Centromeres typically contain repeat sequences, but centromere function does not necessarily depend on these sequences. In aneuploid wheat (Triticum aestivum) and wheat distant hybridization offspring, we found functional centromeres with dramatic changes to centromeric retrotransposon of wheat (CRW) sequences. CRW sequences were greatly reduced in the ditelosomic lines 1BS, 5DS, 5DL, and a wheat-Thinopyrum elongatum addition line. CRWs were completely lost in the ditelosomic line 4DS, but a 994 kb ectopic genomic DNA sequence was involved in de novo centromere formation on the 4DS chromosome. In addition, two ectopic sequences were incorporated in a de novo centromere in a wheat-Th. intermedium addition line. Centromeric sequences were also expanded to the chromosome arm in wide hybridizations. Stable alien chromosomes with two and three regions containing centromeric sequences were found in wheat-Th. elongatum hybrid derivatives, but only one is functional. In wheat-rye (Secale cereale) hybrids, rye centromere specific sequences spread to the chromosome arm and may cause centromere expansion. Thus, distant wheat hybridizations cause frequent and significant changes to the centromere via centromere misdivision, which may affect retention or loss of alien chromosomes in hybrids. ChIP-seq was carried out with anti-CENH3 antibody using material 4DS and control (Chinese Spring, CS as short).
Project description:Transcriptional profiling of three different genotypes (wheat cv Chinese Spring, and the wheat-rye addition lines 3R and 6R) comparing control and 24h exposure to 200 μM de AlCl3. The goal was to determine the effects of AlCl3 on global gene expression in each genotype and study the differences between them.
Project description:Centromeres typically contain repeat sequences, but centromere function does not necessarily depend on these sequences. In aneuploid wheat (Triticum aestivum) and wheat distant hybridization offspring, we found functional centromeres with dramatic changes to centromeric retrotransposon of wheat (CRW) sequences. CRW sequences were greatly reduced in the ditelosomic lines 1BS, 5DS, 5DL, and a wheat-Thinopyrum elongatum addition line. CRWs were completely lost in the ditelosomic line 4DS, but a 994 kb ectopic genomic DNA sequence was involved in de novo centromere formation on the 4DS chromosome. In addition, two ectopic sequences were incorporated in a de novo centromere in a wheat-Th. intermedium addition line. Centromeric sequences were also expanded to the chromosome arm in wide hybridizations. Stable alien chromosomes with two and three regions containing centromeric sequences were found in wheat-Th. elongatum hybrid derivatives, but only one is functional. In wheat-rye (Secale cereale) hybrids, rye centromere specific sequences spread to the chromosome arm and may cause centromere expansion. Thus, distant wheat hybridizations cause frequent and significant changes to the centromere via centromere misdivision, which may affect retention or loss of alien chromosomes in hybrids.
Project description:Five RNA samples were used. The RNA source material was from wheat cytogenetic stocks from Dr. Adam Lukaszewski, University of California, Riverside. The lines used for this study are Pavon, Pavon Dt1BL, 1RS.1BL, 1B+5 and T-1 wheat samples. whole seedling minus starchy endosperm. Equal portions of RNA from unstressed and 48 hr drought-stressed seedling were combined to make one RNA sample. The person who produced the RNA was Prasanna R. Bhat in the TJ Close lab at University of California, Riverside. Everything downstream of RNA production was done at the UC Irvine DNA and Protein Microarray Facility (Denis Heck, manager) by Sriti Misra. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Prasanna Bhat. The equivalent experiment is TA10 at PLEXdb.] genetic line: Pavon(2-replications); genetic line: Pavon Dt1BL(2-replications); genetic line: 1RS.1BL(2-replications); genetic line: T-1(2-replications); genetic line: 1B+5(2-replications)
Project description:We have a limited understanding of how the complexity of the wheat genome influences the distribution of chromatin states along the homoeologous chromosomes. Using a differential nuclease sensitivity (DNS) assay, we investigated the chromatin states in the coding and transposon element (TE) -rich repetitive regions of the allopolyploid wheat genome.