Usher Jane, Bond Ursula
Trinity College Dublin, Ireland.
Appl Environ Microbiol. 2009 Jul;75(13):4573-9. doi: 10.1128/AEM.00351-09. Epub 2009 May 8.
Yeasts used in the production of lagers contain complex allopolyploid genomes, resulting from the fusion of two different yeast species closely related to Saccharomyces cerevisiae and Saccharomyces bayanus. Recombination between the homoeologous chromosomes has generated a number of hybrid chromosomes. These recombination events provide potential for adaptive evolution through the loss or gain of gene function. We have examined the genotypic and phenotypic effects of one of the conserved recombination events that occurred on chromosome XVI in the region of YPR159W and YPR160W. Our analysis shows that the recombination event occurred within the YPR160W gene, which encodes the enzyme glycogen phosphorylase and generates a hybrid gene that does not produce mature mRNA and is nonfunctional due to frameshifts in the coding region. The loss of function of the hybrid gene leads to glycogen levels similar to those found in haploid yeast strains. The implications for the control of glycogen levels in fermentative yeasts are discussed.
用于生产拉格啤酒的酵母含有复杂的异源多倍体基因组，这些基因组由与酿酒酵母和巴氏酵母密切相关的两种不同酵母物种融合而成。同源染色体之间的重组产生了许多杂交染色体。这些重组事件通过基因功能的丧失或获得为适应性进化提供了潜力。我们研究了在YPR159W和YPR160W区域的第十六条染色体上发生的一个保守重组事件的基因型和表型效应。我们的分析表明，重组事件发生在YPR160W基因内，该基因编码糖原磷酸化酶，产生一个杂合基因，该基因不产生成熟的mRNA，并且由于编码区的移码而无功能。杂合基因功能的丧失导致糖原水平与单倍体酵母菌株中的糖原水平相似。本文讨论了其对发酵酵母中糖原水平控制的影响。
