Per aspera ad astra: When harmful chromosomal translocations become a plus value in genetic evolution. Lessons from Saccharomyces cerevisiae
Authors:Valentina Tosato and Carlo V. Bruschi
doi: 10.15698/mic2015.10.230
Volume 2, pp. 363 to 375, published 20/08/2015.
Yeast Molecular Genetics Laboratory, International Centre for Genetic Engineering and Biotechnology, Trieste, Italy.
Keywords:
adaptation, BIT, chromosomal translocation, evolution, rearrangements, yeast
Corresponding Author(s):
Conflict of interest statement:
The authors declare no conflict of interest.
Please cite this article as:
Valentina Tosato and Carlo V. Bruschi (2015). Per aspera ad astra: When harmful chromosomal translocations become a plus value in genetic evolution. Lessons from Saccharomyces cerevisiae. Microbial Cell2(10): 363-375.
© 2015 Tosato and Bruschi. This is an open-access article released under the terms of the Creative Commons Attribution (CC BY) license, which allows the unrestricted use, distribution, and reproduction in any medium, provided the original author and source are acknowledged.
Abstract:
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 Saccharomyces, 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-loxP procedure, the FLP/FRT 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.