Tosato Valentina, Bruschi Carlo V
Yeast Molecular Genetics Laboratory, International Centre for Genetic Engineering and Biotechnology, Trieste, Italy.
Microb Cell. 2015 Aug 20;2(10):363-375. doi: 10.15698/mic2015.10.230.
In this review we will focus on chromosomal translocations (either spontaneous or induced) in budding yeast. Indeed, very few organisms tolerate so well aneuploidy like , allowing in depth studies on chromosomal numerical aberrations. Many wild type strains naturally develop chromosomal rearrangements while adapting to different environmental conditions. Translocations, in particular, are valuable not only because they naturally drive species evolution, but because they might allow the artificial generation of new strains that can be optimized for industrial purposes. In this area, several methodologies to artificially trigger chromosomal translocations have been conceived in the past years, such as the chromosomal fragmentation vector (CFV) technique, the Cre- procedure, the FLP/ recombination method and, recently, the bridge - induced translocation (BIT) system. An overview of the methodologies to generate chromosomal translocations in yeast will be presented and discussed considering advantages and drawbacks of each technology, focusing in particular on the recent BIT system. Translocants are important for clinical studies because translocated yeast cells resemble cancer cells from morphological and physiological points of view and because the translocation event ensues in a transcriptional de-regulation with a subsequent multi-factorial genetic adaptation to new, selective environmental conditions. The phenomenon of post-translocational adaptation (PTA) is discussed, providing some new unpublished data and proposing the hypothesis that translocations may drive evolution through adaptive genetic selection.
在本综述中，我们将聚焦于芽殖酵母中的染色体易位（自发的或诱导的）。事实上，很少有生物能像芽殖酵母那样耐受非整倍体，这使得对染色体数目畸变进行深入研究成为可能。许多野生型菌株在适应不同环境条件时会自然发生染色体重排。特别是易位，不仅因其自然推动物种进化而具有价值，还因为它们可能允许人工培育出可针对工业用途进行优化的新菌株。在这一领域，过去几年已经构思了几种人工引发染色体易位的方法，例如染色体片段化载体（CFV）技术、Cre-loxP程序、FLP/FRT重组方法，以及最近的桥接诱导易位（BIT）系统。我们将介绍并讨论酵母中产生染色体易位的方法概述，考量每种技术的优缺点，尤其关注最近的BIT系统。易位体对于临床研究很重要，因为从形态学和生理学角度来看，易位的酵母细胞类似于癌细胞，并且因为易位事件会导致转录失调，随后会对新的选择性环境条件进行多因素遗传适应。我们将讨论易位后适应（PTA）现象，提供一些未发表的新数据，并提出易位可能通过适应性遗传选择推动进化的假说。
