Project description:mRNA expression profiling of the embryo, endosperm (micropylar, peripheral, chalazal), and seed coat (outer, inner, chalazal, chalazal proliferating tissue) of the developing Brassica napus seed. Tissues were isolated using laser microdissection (LMD) from Brassica napus seeds at the globular, heart, and mature green stages of seed development.
Project description:High temperature stress results in yield loss and alterations to seed composition during seed filling in oilseed rape (Brassica napus). However, the mechanism underlying this heat response is poorly understood. In this study, we employed a microarray analysis with silique walls and seeds from the developing siliques (20 days after flowering) of Brassica napus that had undergone heat stress.
Project description:Gene expression profiles during seed development and fatty acid (FA) metabolism, as well as the relevant regulation, of Brassica napus were studied through multiple high-throughput genomic approaches. Serial Analysis of Gene Expression (SAGE) using seed materials obtained a total of 68,718 tags, of which 23,897 were unique and 503 tags were functionally identified, and revealed the transcriptome of approximately 35,000 transcripts in B. napus developing seeds. Further, ~22,000 independent ESTs were obtained by large-scale sequencing using immature embryos at different stages, and 8343 uni-ESTs and 3355 full-length cDNAs were identified respectively, resulting in the systemic identification of B. napus FA biosynthesis-related genes. Gene expression profiles were further studied employing cDNA chip hybridization to reveal the global regulatory network of FA metabolism in developing seeds. Together with the analysis on FA amounts and composition, it was shown that 17-21 days after pollination (DAP) was a crucial stage for transition of seed to sink tissue. High expressions of FA biosynthesis-related genes and transition of FA components are mainly at stages 21 DAP or 21-25 DAP respectively. In addition, compared to Arabidopsis, more critical roles of starch metabolism are detected for B. napus seed FA metabolism and storage components accumulation. Crucial effects of starch metabolism, carbon flux, oxidative pentose phosphate pathway (OPPP), photosynthesis, and other regulators in FA metabolism were discussed. Keywords: Brassica napus, immature seed, SAGE, EST, cDNA microarray
Project description:Illumina mRNA-Seq is comparable to microarray analysis for transcript quantification but has increased sensitivity and, importantly, the potential to distinguish between homoeologous genes in polyploids. Using a novel curing process, we adapted a reference sequence that was a consensus derived from ESTs from both Brassica A and C genomes to one containing A and C genome versions for each of the 94,558 original unigenes. We aligned reads from Brassica napus to this cured reference, finding 38% more reads mapping in resynthesised lines and 28% in natural lines. Where the A and C versions differed at single nucleotide positions, termed inter-homoeologue polymorphisms (IHPs), we were able to apportion expression in the polyploid to the A or C genome homoeologues. 43,761 unigenes contained at least one IHP, with a mean frequency of 10.5 per kb unigene sequence. 6,350 of the unigenes with IHPs were differentially expressed between homoeologous gene pairs in resynthesised B. napus. 3,212 unigenes showed a similar pattern of differential expression across a range of natural B. napus crop varieties and, of these, 995 were in common with resynthesised B. napus. Functional classification showed over-representation in gene ontology categories not associated with dosage-sensitivity.
Project description:High temperature stress results in yield loss and alterations to seed composition during seed filling in oilseed rape (Brassica napus). However, the mechanism underlying this heat response is poorly understood. In this study, we employed a microarray analysis with silique walls and seeds from the developing siliques (20 days after flowering) of Brassica napus that had undergone heat stress. Two-condition experiment, control vs heat stress, 2 time points
Project description:Time course of gene expression profiles during seed development and maturation in Brassica napus were studied using Combimatrix Brassica microarray.
Project description:Serial Analysis of Gene Expression (LongSAGE) was applied for gene expression profiling in seeds of oilseed rape (Brassica napus ssp. napus). The usefulness of this technique for detailed expression profiling in a non-model organism was demonstrated for the highly complex, neither fully sequenced nor annotated genome of B. napus by applying a tag-to-gene matching strategy based on Brassica ESTs and the annotated proteome of the closely related model crucifer A. thaliana. Transcripts from 3,094 genes were detected at two time-points of seed development, 23 days and 35 days after pollination (DAP). Differential expression in about 10 % of all matched genes, with a total abundance of 44 %, showed a shift from gene expression involved in diverse developmental processes including cell proliferation and seed coat formation at 23 DAP to more focussed metabolic processes including storage protein accumulation and lipid deposition at 35 DAP. The most abundant transcripts at 23 DAP were coding for diverse protease inhibitor proteins and proteases, including cysteine proteases involved in seed coat formation and a number of lipid transfer proteins involved in embryo pattern formation. At 35 DAP, transcripts encoding napin, cruciferin and oleosin storage proteins were most abundant. Over both time-points, 18.6 % of A. thaliana genes were matched by Brassica ESTs detected by LongSAGE tags in antisense orientation. This suggests a strong involvement of antisense transcript expression in regulatory processes during B. napus seed development.
Project description:Time course of gene expression profiles during seed development and maturation in Brassica napus were studied using Combimatrix Brassica microarray. The time course expression of 90K Brassica napus EST contigs were measured at 8 developing seed stages of 10, 15, 20, 25, 30, 35, 40 and 45 DAF (days after flowering) using single color microarray
Project description:Serial Analysis of Gene Expression (LongSAGE) was applied for gene expression profiling in seeds of oilseed rape (Brassica napus ssp. napus). The usefulness of this technique for detailed expression profiling in a non-model organism was demonstrated for the highly complex, neither fully sequenced nor annotated genome of B. napus by applying a tag-to-gene matching strategy based on Brassica ESTs and the annotated proteome of the closely related model crucifer A. thaliana. Transcripts from 3,094 genes were detected at two time-points of seed development, 23 days and 35 days after pollination (DAP). Differential expression in about 10 % of all matched genes, with a total abundance of 44 %, showed a shift from gene expression involved in diverse developmental processes including cell proliferation and seed coat formation at 23 DAP to more focussed metabolic processes including storage protein accumulation and lipid deposition at 35 DAP. The most abundant transcripts at 23 DAP were coding for diverse protease inhibitor proteins and proteases, including cysteine proteases involved in seed coat formation and a number of lipid transfer proteins involved in embryo pattern formation. At 35 DAP, transcripts encoding napin, cruciferin and oleosin storage proteins were most abundant. Over both time-points, 18.6 % of A. thaliana genes were matched by Brassica ESTs detected by LongSAGE tags in antisense orientation. This suggests a strong involvement of antisense transcript expression in regulatory processes during B. napus seed development. Seeds from 2 developmental stages of B. napus were used to construct 2 LongSAGE libraries, 23 days after pollination (23 DAP) and 35 days after pollination (35 DAP). Biological replicates and confirmation: Cloning of tag-amplified RT-PCR products, Real-time RT-PCR