Deciphering the molecular basis of wine yeast fermentation traits using a combined genetic and genomic approach.
Deciphering the molecular basis of wine yeast fermentation traits using a combined genetic and genomic approach.
复制标题
DOI：
10.1534/g3.111.000422
复制
发表时间：
2011-09
期刊：
影响因子：
--
通讯作者：
Blondin B
中科院分区：
文献类型：
--
作者：
Ambroset C;Petit M;Brion C;Sanchez I;Delobel P;Guérin C;Chiapello H;Nicolas P;Bigey F;Dequin S;Blondin B
酵母表型多样性的遗传基础仍然知之甚少。与其他菌株相比，葡萄酒酵母菌株具有在压力条件下生长和发酵的特定能力，但这些特征的遗传基础尚不清楚。了解序列变异如何影响这些表型是解决葡萄酒酵母适应机制的主要挑战。我们的目标是确定发酵特性的遗传基础，并深入了解它们与酵母菌株之间基因表达差异的关系。我们结合了发酵性状QTL定位和发酵细胞在分离群体中的表达谱，这些细胞来自葡萄酒酵母衍生物和实验室菌株的杂交。我们报道了不同发酵性状(发酵率、氮素利用、代谢物生产)的QTL以及表达QTL(EQTL)。我们发现，许多转录本定位于几个eQTL热点，其中两个与发酵性状的QTL重叠。分析了一个与eQTL热点重叠的控制最大发酵速率和氮素利用的QTL。我们从功能上证明了ABZ1基因的一个等位基因，定位于热点区域，参与了对氨基苯甲酸的生物合成，通过调节氮素利用来控制发酵速度。我们的数据表明，实验室菌株含有一个有缺陷的ABZ1等位基因，它触发了导致eQTL热点产生的强烈的代谢和生理变化。他们还提出，一些基因表达的差异是由一些引发重大生理障碍的等位基因造成的。
The genetic basis of the phenotypic diversity of yeast is still poorly understood. Wine yeast strains have specific abilities to grow and ferment under stressful conditions compared with other strains, but the genetic basis underlying these traits is unknown. Understanding how sequence variation influences such phenotypes is a major challenge to address adaptation mechanisms of wine yeast. We aimed to identify the genetic basis of fermentation traits and gain insight into their relationships with variations in gene expression among yeast strains. We combined fermentation trait QTL mapping and expression profiling of fermenting cells in a segregating population from a cross between a wine yeast derivative and a laboratory strain. We report the identification of QTL for various fermentation traits (fermentation rates, nitrogen utilization, metabolites production) as well as expression QTL (eQTL). We found that many transcripts mapped to several eQTL hotspots and that two of them overlapped with QTL for fermentation traits. A QTL controlling the maximal fermentation rate and nitrogen utilization overlapping with an eQTL hotspot was dissected. We functionally demonstrated that an allele of the ABZ1 gene, localized in the hotspot and involved in p-aminobenzoate biosynthesis, controls the fermentation rate through modulation of nitrogen utilization. Our data suggest that the laboratory strain harbors a defective ABZ1 allele, which triggers strong metabolic and physiological alterations responsible for the generation of the eQTL hotspot. They also suggest that a number of gene expression differences result from some alleles that trigger major physiological disturbances.