A Mutation Allowing Expression of Normally Silent a Mating-Type Information in SACCHAROMYCES CEREVISIAE
AUTOR(ES)
Gruenspan, Harry
RESUMO
Mating type in haploid cells of the yeast Saccharomyces cerevisiae is determined by a pair of alleles MATa and MATα . Under various conditions haploid mating types can be interconverted. It has been proposed that transpositions of silent cassettes of mating-type information from HML or HMR to MAT are the source of mating type conversions. A mutation described in this work, designated AON1, has the following properties. (1) MATα cells carring AON1 are defective in mating. (2) AON1 allows MATα/MATα but not MATa/MATa diploids to sporulate; thus, AON1 mimics the MATa requirement for sporulation. (3) mata-1 cells that carry AON1 are MATa phenocopies, i.e., MATα/mata- 1 AON1 diploids behave as standard MATα/MATa cells; therefore, AON1 suppresses the defect of mata- 1. (4) AON1 maps at or near HMRa. (5) Same-site revertants from AON1 lose the ability to convert mating type to MATa, indicating that reversion is associated with the loss of a functional HMRa locus. In addition, AON1 is a dominant mutation. We conclude that AON1 is a regulatory mutation, probably cis-acting, that leads to the constitutive expression of silent a mating-type information located at HMRa.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1202072Documentos Relacionados
- A Mutation That Permits the Expression of Normally Silent Copies of Mating-Type Information in SACCHAROMYCES CEREVISIAE
- The sum1-1 mutation affects silent mating-type gene transcription in Saccharomyces cerevisiae.
- A Suppressor of Mating-Type Locus Mutations in SACCHAROMYCES CEREVISIAE: Evidence for and Identification of Cryptic Mating-Type Loci
- Mating-Type Regulation of Methyl Methanesulfonate Sensitivity in SACCHAROMYCES CEREVISIAE
- Gene Conversion of the Mating-Type Locus in SACCHAROMYCES CEREVISIAE