Recent attempts to characterise the hybrid strains of Cryptococcus neoformans have led to the identification of a cryptic population of hybrid strains ('H strains') with double DNA content but only a single mating-type allele. To verify a set of hypotheses concerning their origin, we investigated 14 previously isolated H strains and ten F1-progeny strains arising from H99 and JEC20 mating. The double DNA content was tested by flow cytometry; the presence of only one mating type was tested by amplifying 12 mating-type-specific genes and one gene unlinked with the mating-type locus (URA5). Analysis of the F1 progeny identified two H strains, and electrophoretic karyotyping confirmed the occurrence of genetic recombination. The simultaneous presence of the homozygous and heterozygous loci, and the fact that all of the F1-progeny strains presented a recombinant karyotype, suggest that the H strains originated from the post-meiotic random fusion of two of the four recombinant nuclei. Further studies are required to elucidate the role of the homozygous mating-type loci in the virulence of C. neoformans.
http://hdl.handle.net/2434/25096
Titolo: | Cryptococcus neoformans population includes hybrid strains homozygous at mating-type locus |
Autori: | COGLIATI, MASSIMO (Primo) ESPOSTO, MARIA CARMELA (Secondo) TORTORANO, ANNA MARIA (Penultimo) |
Settore Scientifico Disciplinare: | Settore MED/42 - Igiene Generale e Applicata |
Data di pubblicazione: | giu-2006 |
URL: | http://www.blackwell-synergy.com/doi/abs/10.1111/j.1567-1364.2006.00085.x |
Tipologia: | Article (author) |
Digital Object Identifier (DOI): | 10.1111/j.1567-1364.2006.00085.x |
Appare nelle tipologie: | 01 - Articolo su periodico |