Natural variation in non-coding regions underlying phenotypic diversity in budding yeast

Area of Science:

• Genetics
• Molecular Biology
• Yeast Research

Background:

• Phenotypic diversity is often linked to gene expression variation.
• Polymorphisms in regulatory regions are understudied but can influence gene expression.
• Limited molecular evidence exists linking genotype to phenotype via expression differences.

Purpose of the Study:

• To investigate Allele Specific Expression (ASE) in Saccharomyces cerevisiae hybrids.
• To identify molecular evidence for gene expression variation contributing to phenotypic diversity.
• To explore the role of regulatory variants in yeast gene expression and trait differences.

Main Methods:

• Analysis of ASE in six F1 yeast hybrids from crosses between four main lineages.
• Examination of transcription factor binding to polymorphic cis-regulatory regions.
• Allele swap analysis of promoter regions under fermentation conditions.

Main Results:

• ASE varied significantly between crosses (28%-60%).
• Differences in transcription factor binding and trans-activation explained expression variations.
• ASN1 identified as a candidate transcript for nitrogen consumption differences.
• Polymorphisms in coding and non-coding regions, affecting Uga3 binding, explained amino acid consumption differences.

Conclusions:

• Regulatory variants play a crucial role in driving gene expression and phenotypic variation in yeast.
• This study provides a valuable catalogue of variants connecting genotype to phenotype.
• Understanding allele-specific expression is key to deciphering genotype-phenotype relationships.