Project description:Following previous work, we extend the use of a reliable detection method to a wide progeny in white spruce in order to genetically map a maximum of inherited gene CNVs and linked those to phenotypic traits related to adaptation. We selected probes targeting 3911 genes likely in CNV in this progeny and performed genetic mapping for those harboring a 1:1 segregation. In addition, the link between gene CNVs and phenotypic variation was tested using budburst, budset and growth data for the same samples. Results: We genetically mapped 82 gene CNVs inherited from the previous generation and harboring the expected segregation ratio. This mapping allowed to delineate a few hotspots of CNV that are likely shared with other conifer species. In addition, individual-specific gene CNVs likely representing de novo variation supported the hypothesis of a purifying selection against copy losses. Finally, 29 gene CNVs were significantly associated to adaptive trait variation; 13 were located on the genetic map, including 4 located within hotspots of CNVs.
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:White pine weevil is a major pest of conifers in North America, especially for Spruce trees. Constitutive defenses are important in understanding defense mechanisms because they constitute the initial barrier to attacks by weevils and other pests. Resistant and susceptible trees exhibit constitutive differences in spruce. To improve our knowledge of their genetic basis, we compared the constitutive expression levels of 17,825 genes between 20 resistant and 20 susceptible trees in interior spruce (Picea glauca).
Project description:White pine weevil is a major pest of conifers in North America, especially for Spruce trees. Constitutive defenses are important in understanding defense mechanisms because they constitute the initial barrier to attacks by weevils and other pests. Resistant and susceptible trees exhibit constitutive differences in spruce. To improve our knowledge of their genetic basis, we compared the constitutive expression levels of 17,825 genes between 20 resistant and 20 susceptible trees in interior spruce (Picea glauca). Twenty hybridizations were performed to compare untreated bark of resistant and susceptible trees.RNA isolated from each of the 20 individual untreated resistant trees was compared directly against the 20 individual untreated susceptble trees using two hybridizations with a dye flip for each tree pair.
Project description:Defense mechanisms against herbivory: expression regulation of spruce gene family members representative of the phenylpropanoid pathway
Project description:Transcript profiling reveals a molecular signature that distinguishes early versus late time to bud set phenotypes in a white spruce full-sib family.
Project description:Potential link between biotic defense activation and recalcitrance to induction of somatic embryogenesis in shoot primordia from adult trees of white spruce (Picea glauca)