ISSN:
1432-0983
Keywords:
Saccharomyces cerevisiae
;
Hydrostatic pressure
;
Tetraploidy
;
Homozygous diploid
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Hydrostatic pressure and a dye plate method were used to investigate the direct induction of tetraploids or homozygous diploids from the industrial diploid or haploid yeast Saccharomyces cerevisiae. Above 200 MPa, hydrostatic pressure greatly inactivated the strains HF399s1 (α haploid), P-540 (a/α diploid), and P-544 (a/α diploid). At the same time, when pressure-treated cells of these strains were spread on a dye plate, some of the visible colonies were stained red/blue or dark blue (variant colonies); the rest stained violet, similar to colonies originating from diploid cells or haploid cells that were not pressure-treated. In addition, above 100 MPa, the formation of variant colonies increased with increasing pressure, and maximized (1x10-1) at 200 and 250 MPa, respectively. The size of almost all variant cells from P-544, P-540, and HF399s1 was visibly increased compared with that of untreated cells and the measured cellular DNA content of P-540 and HF399s1 was double that of untreated cells. Furthermore, based on random spore analysis and mass-matings, induced variants in the diploid strains were found to be tetraploid with an a/a/α/α genotype at the mating-type locus or, in the haploid strains, homozygous diploid with an α/α genotype. From these results we conclude that pressure treatment in combination with a dye plate is a useful method for strain improvement by direct induction of tetraploids or homozygous diploids from industrial strains whether diploid or haploids.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00352438
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