Author/Editor     Marinoni, Gaelle; Manuel, Martine; Petersen, Randi Fons; Hvidtfeldt, Jeanne; Sulo, Pavol; Piškur, Jure
Title     Horizontal transfer of genetic material among Saccharomyces yeasts
Type     članek
Source     J Bacteriol
Vol. and No.     Letnik 181, št. 20
Publication year     1999
Volume     str. 6488-96
Language     eng
Abstract     The genus Saccharomyces consists of several species divided into the sensu stricto and the sensu lato groups. The genomes of these species differ in the number and organization of nuclear chromosomes and in the size and organization of mitochondrial DNA (mtDNA). In the present experiments we examined whether these yeasts can exchange DNA and thereby create novel combinations of genetic material. Several putative haploid, heterothallic yeast strains were isolated from different Saccharomyces species. All of these strains secreted an a- or alpha-like pheromone recognized by S. cerevisiae tester strains. When interspecific crosses were performed by mass mating between these strains, hybrid zygotes were often detected. In general, the less related the two parental species were, the fewer hybrids they gave. For some crosses, viable hybrids could be obtained by selection on minimal medium and their nuclear chromosomes and mtDNA were examined. Often the frequency of viable hybrids was very low. Sometimes putative hybrids could not be propagated at all. In the case of sensu stricto yeasts, stable viable hybrids were obtained. These contained both parental sets of chromosomes but mtDNA from only one parent. In the case of sensu lato hybrids, during genetic stabilization one set of the parental chromosomes was partially or completely lost and the stable mtDNA originated from the same parent as the majority of the nuclear chromosomes. Apparently, the interspecific hybrid genome was genetically more or less stable when the genetic material originated from phylogenetically relatively closely related parents; both sets of nuclear genetic material could be transmitted and preserved in the progeny. In the case of more distantly related parents, only one parental set, and perhaps some fragments of the other one, could be found in genetically stabilized hybrid lines. (Abstract truncated at 2000 characters)
Descriptors     EVOLUTION, MOLECULAR
CELL NUCLEUS
CHIMERA
CHROMOSOMES, FUNGAL
CROSSES, GENETIC
DNA, FUNGAL
ETHYL METHANESULFONATE
HAPLOIDY
MITOCHONDRIA
MODELS, GENETIC
MUTAGENESIS
MUTAGENS
PHEROMONES
SACCHAROMYCES
SACCHAROMYCES CEREVISIAE
ZYGOTE