Ibeas J I, Jimenez J
Departamento de Genetica, Facultad de Ciencias, Universidad de Malaga, Campus Universitario de Teatinos, E-29071 Malaga, Spain.
Curr Genet. 1996 Nov;30(5):410-6. doi: 10.1007/s002940050150.
In this report we describe the genomic complexity of a number of Saccharomyces yeast strains isolated from sherry wine (flor yeasts), and the genomic stability of a yeast hybrid derived from one of these and a laboratory strain. Flor yeast strains largely differed in their DNA content, but showed very few variations their molecular karyotype. These strains contained a large number of Ty2 sequences, but lacking the Ty1 elements commonly found in laboratory strains. The genetic analysis of a flor-laboratory hybrid indicated that flor yeasts were aneuploid. Hybridization patterns obtained with Ty1 and Ty2 probes in the meiotic progeny of this hybrid suggested that recombination may occur not only among homologous chromosomes of similar length, but also among polymorphic partners with different sizes. New chromosomal variants were frequently observed in the meiotic products, suggesting that polymorphism in chromosome length may itself be a major source of karyotypic variation. The genetic analysis of such variants indicated that recombinational events leading to new chromosomal forms may occur both mitotically and meiotically.
在本报告中，我们描述了从雪莉酒中分离出的若干酿酒酵母菌株（弗洛酵母）的基因组复杂性，以及源自其中一个菌株与实验室菌株的酵母杂交种的基因组稳定性。弗洛酵母菌株在DNA含量上有很大差异，但在分子核型上变化很少。这些菌株含有大量的Ty2序列，但缺乏实验室菌株中常见的Ty1元件。对弗洛酵母与实验室菌株杂交种的遗传分析表明，弗洛酵母是非整倍体。用Ty1和Ty2探针在该杂交种的减数分裂后代中获得的杂交模式表明，重组不仅可能发生在长度相似的同源染色体之间，也可能发生在大小不同的多态性配对染色体之间。在减数分裂产物中经常观察到新的染色体变体，这表明染色体长度的多态性本身可能是核型变异的主要来源。对这些变体的遗传分析表明，导致新染色体形式的重组事件可能在有丝分裂和减数分裂过程中都发生。
