Restoring fertility in yeast hybrids: breeding and quantitative genetics of beneficial traits
Restoring fertility in yeast hybrids: breeding and quantitative genetics of beneficial traits
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恢复酵母杂交的生育力：有益性状的育种和数量遗传学
DOI：
10.1101/2021.01.21.427634
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Naseeb S
中科院分区：
文献类型：
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作者：
Naseeb S
物种之间的杂交可以拥有来自每个亲本的有益特征的组合，并可能显示出杂交活力，更容易适应新的更严酷的环境。物种间的杂交也是不育的，因此是进化的死胡同，除非恢复生育能力，通常是通过自动多倍化事件。在酵母属中，杂交种很容易在自然界和工业环境中找到，在那里它们已经适应了严格的发酵条件。由于它们的杂交不育，到目前为止，开发新的商业酵母菌株主要是通过选择方法进行的，而不是通过进一步的育种。在这项研究中，我们通过创造酵母种间杂交的四倍体中间体来克服不育症，从而实现连续的多世代育种。我们在每个亲本物种中纳入了核和线粒体遗传多样性，允许对杂交后代表现出的特征进行定量遗传分析，并对核-线粒体相互作用进行评估。利用具有极端表型分布的不同杂交种的F12代分离株，我们定位了耐高、低温、高糖、高乙醇浓度和醋酸水平的数量性状基因座。我们确定了物种特有的、种间共有的QTL以及杂交特有的QTL，在这些QTL中，变异体在原始亲本物种中没有表现出表型差异。此外，我们可以区分线粒体类型依赖的特征和独立的特征。本研究解决了杂交种遗传互作和性状的复杂性，将杂交种带入二倍体物种的完全遗传分析领域，为酵母生物多样性的生物技术开发铺平了道路。
Hybrids between species can harbor a combination of beneficial traits from each parent and may exhibit hybrid vigor, more readily adapting to new harsher environments. Interspecies hybrids are also sterile and therefore an evolutionary dead end unless fertility is restored, usually via auto-polyploidisation events. In theSaccharomycesgenus, hybrids are readily found in nature and in industrial settings, where they have adapted to severe fermentative conditions. Due to their hybrid sterility, the development of new commercial yeast strains has so far been primarily conducted via selection methods rather than via further breeding. In this study, we overcame infertility by creating tetraploid intermediates ofSaccharomycesinterspecies hybrids to allow continuous multigenerational breeding. We incorporated nuclear and mitochondrial genetic diversity within each parental species, allowing for quantitative genetic analysis of traits exhibited by the hybrids and for nuclear–mitochondrial interactions to be assessed. Using pooled F12 generation segregants of different hybrids with extreme phenotype distributions, we identified quantitative trait loci (QTLs) for tolerance to high and low temperatures, high sugar concentration, high ethanol concentration, and acetic acid levels. We identified QTLs that are species specific, that are shared between species, as well as hybrid specific, in which the variants do not exhibit phenotypic differences in the original parental species. Moreover, we could distinguish between mitochondria-type–dependent and –independent traits. This study tackles the complexity of the genetic interactions and traits in hybrid species, bringing hybrids into the realm of full genetic analysis of diploid species, and paves the road for the biotechnological exploitation of yeast biodiversity.