Project description:Based on the generation of ESTs, we developed a spruce cDNA microarray composed of 21,843 cDNA elements selected from 12 cDNA libraries representing developmental stages of xylem, phloem, bark and roots, as well as elicitor-treated bark. Clones on the array were selected from a CAP3 assembly of 50,770 hq 3’ ESTs, and were carefully chosen to represent a minimally redundant gene set. Using this array we examined global changes in the transcriptome of Sitka spruce attacked for two days by stem-boring white pine weevils. Differentially expressed genes were determined using three criteria: fold-change between weevil-treated and untreated control > 1.5-fold, P value < 0.05 and Q value < 0.05. After 48 h of weevil feeding, 1,857 (8.5%) microarray elements identified transcripts as up-regulated, compared to 1,374 (6.3%) down-regulated. Keywords: Stress response
Project description:We developed a reliable CNV detection method for species lacking contiguous reference genome. We selected multiple probes within 14,078 gene sequences and developed comparative genome hybridization on arrays. Gene CNVs were assessed in three full-sib families from species with 20 Gb genomes, i.e. white and black spruce, and interior spruce - a natural hybrid. Results: We discovered hundreds of gene CNVs in each species, 3612 in total, which were enriched in functions related to stress and defense responses and narrow expression profiles, indicating a potential role in adaptation. The number of shared CNVs was in accordance with the degree of relatedness between individuals and species. The genetically mapped subset of these genes showed a wide distribution across the genome, implying numerous structural variations. The hybrid family presented significantly fewer CNVs, suggesting that the admixture of two species within one genome reduces the occurrence of CNVs.
Project description:Using 21K spruce microarray (that contains 21.8 thousand unique transcripts) we performed analysis of the transcriptome response of interior spruce (Picea glauca x engelmannii) inoculated with the spruce beetle (Dendroctonus rufipennis) vectored blue stain fungal pathogen Leptographium abietinum or treated with wounding. This microarray analysis revealed large transcriptome reorganization with close to 2000 transcripts (10% of the studied transcriptome) differentially expressed within two weeks of treatment, with the wounding response affecting close to 5% of the interior spruce transcriptome.