Assessment of shared alleles in drought-associated candidate genes among southern California white oak species (Quercus sect. Quercus).
BMC Genet
; 19(1): 88, 2018 10 01.
Article
em En
| MEDLINE
| ID: mdl-30285631
ABSTRACT
BACKGROUND:
Hybridization and introgression are common phenomena among oak species. These processes can be beneficial by introducing favorable genetic variants across species (adaptive introgression). Given that drought is an important stress, impacting physiological and morphological variation and limiting distributions, our goal was to identify drought-related genes that might exhibit patterns of introgression influenced by natural selection. Using RNAseq, we sequenced whole transcriptomes of 24 individuals from three oaks in southern California (Quercus engelmannii, Quercus berberidifolia, Quercus cornelius-mulleri) and identified genetic variants to estimate admixture rates of all variants and those in drought genes.RESULTS:
We found 398,042 variants across all loci and 4352 variants in 139 drought candidate genes. STRUCTURE analysis of all variants revealed the majority of our samples were assignable to a single species, but with several highly admixed individuals. When using drought-associated variants, the same individuals exhibited less admixture and their allele frequencies were more polarized between Engelmann and scrub oaks than when using the total gene set. These findings are consistent with the hypothesis that selection may act differently on functional genes, such as drought-associated genes, and point to candidate genes that are suggestive of divergent selection among species maintaining adaptive differences. For example, the drought genes that showed the strongest bias against engelmannii-fixed oak variants in scrub oaks were related to sugar transporter, coumarate-coA ligases, glutathione S-conjugation, and stress response.CONCLUSION:
This pilot study illustrates that whole transcriptomes of individuals will provide useful data for identifying functional genes that contribute to adaptive divergence among hybridizing species.Palavras-chave
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Polimorfismo Genético
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Estresse Fisiológico
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Genes de Plantas
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Transferência Genética Horizontal
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Quercus
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Secas
Tipo de estudo:
Prognostic_studies
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Risk_factors_studies
Idioma:
En
Revista:
BMC Genet
Assunto da revista:
BIOLOGIA MOLECULAR
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BIOTECNOLOGIA
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Turquia