Project description:Salvelinus Microarray experiment: The influence of parental effects on transcriptomic landscape during early development in brook charr (Salvelinus fontinalis, Mitchill)
Project description:Parental effects represent an important source of variation in offspring phenotypes. Depending on the specific mechanisms involved, parental effects may be caused to different degrees by either the maternal or paternal parent, and these effects may in turn act at different stages of development. In order to detect parental effects acting on gene transcription regulation and length phenotype during ontogeny, the transcriptomic profiles of two reciprocal hybrids from LavalM-BM- M-CM-^WM-BM- Rupert and LavalM-BM- M-CM-^WM-BM- domestic populations of brook charr were compared at hatching, yolk sac resorption, and 15 weeks after exogenous feeding. Using a salmonid cDNA microarray, our results show that parental effects modulated gene expression among reciprocal hybrids only at the yolk sac resorption stage. In addition, LavalM-BM- M-CM-^WM-BM- domestic and LavalM-BM- M-CM-^WM-BM- Rupert reciprocal hybrids differed in the magnitude of theses parental effects, with 199 and 630 differentially expressed transcripts, respectively. This corresponds to a maximum of 18.5% of the analyzed transcripts. These transcripts are functionally related to cell cycle, nucleic acid metabolism and intracellular protein traffic, which is consistent with observed differences associated with embryonic development and growth differences in other fish species. Our results thus illustrate how parental effects on patterns of gene transcription seem dependent on the genetic architecture of the parents. In addition, in absence of transcriptomic differences, the non-transcriptomic deposits could also act to highlight the offspring differences in length before the yolk sac resorption. Pair-wise direct comparisons between 8 reciprocal hybrids (LavalRupert vs RupertLaval and LavalDomestic vs DomesticLaval) were performed at each developmental stage. For each developmental stage, cDNA of 8 samples from each cross were hybridized for a total of 48 microarrays analyzed. The distribution of dyes is equilibrated among each cross (4 samples with cy3 and 4 samples with Al647).
