Influence of developmental stage and genotype on liver mRNA levels among wild, domesticated, and hybrid rainbow trout Oncorhynchus mykissReport as inadecuate




Influence of developmental stage and genotype on liver mRNA levels among wild, domesticated, and hybrid rainbow trout Oncorhynchus mykiss - Download this document for free, or read online. Document in PDF available to download.

BMC Genomics

, 14:673

Non-human and non-rodent vertebrate genomics

Abstract

BackgroundRelease of domesticated strains of fish into nature may pose a threat to wild populations with respect to their evolved genetic structure and fitness. Understanding alterations that have occurred in both physiology and genetics as a consequence of domestication can assist in evaluating the risks posed by introgression of domesticated genomes into wild genetic backgrounds, however the molecular causes of these consequences are currently poorly defined. The present study has examined levels of mRNA in fast-growing pure domesticated D, slow-growing age-matched pure wild Wa, slow-growing size-matched pure wild Ws, and first generation hybrid cross W-D rainbow trout Oncorhynchus mykiss to investigate the influence of genotype domesticated vs. wild, and their interactions in hybrids and developmental stage age- or size-matched animals on genetic responses i.e. dominant vs. recessive and specific physiological pathways.

ResultsHighly significant differences in mRNA levels were found between domesticated and wild-type rainbow trout genotypes 321 mRNAs, with many mRNAs in the wild-domesticated hybrid progeny showing intermediate levels. Differences were also found between age-matched and size-matched wild-type trout groups 64 mRNAs, with unique mRNA differences for each of the wild-type groups when compared to domesticated trout Wa: 114 mRNAs, Ws: 88 mRNAs, illustrating an influence of fish developmental stage affecting findings when used as comparator groups to other genotypes. Analysis of differentially expressed mRNAs found for both wild-type trout to domesticated comparisons among the genotypes indicates that 34.8% are regulated consistent with an additive genetic model, whereas 39.1% and 26.1% show a recessive or dominant mode of regulation, respectively. These molecular data are largely consistent with phenotypic data growth and behavioural assessments assessed in domesticated and wild trout strains.

ConclusionsThe present molecular data are concordant with domestication having clearly altered rainbow trout genomes and consequent phenotype from that of native wild populations. Although mainly additive responses were noted in hybrid progeny, the prevalence of dominant and non-additive responses reveals that introgression of domesticated and wild genotypes alters the type of genetic control of mRNA levels from that of wild-type, which may lead to disruption of gene regulation systems important for developing phenotypes for optimal fitness in nature. A clear influence of both fish age and size developmental stage on mRNA levels was also noted in this study, which highlights the importance of examining multiple control samples to provide a comprehensive understanding of changes observed between strains possessing differences in growth rate.

KeywordsGenomics Domestication Growth Rainbow trout Age-matched Size-matched Electronic supplementary materialThe online version of this article doi:10.1186-1471-2164-14-673 contains supplementary material, which is available to authorized users.

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Author: Samantha L White - Dionne Sakhrani - Roy G Danzmann - Robert H Devlin

Source: https://link.springer.com/







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