Sporulation of Saccharomyces cerevisiae in the Absence of a Functional Mitochondrial Genome
AUTOR(ES)
Küenzi, Martin T.
RESUMO
The role of the mitochondrial system during sporulation of Saccharomyces cerevisiae was studied. Addition of ethidium bromide (EthBr) to cells growing in acetate medium resulted in the quantitative (>98%) conversion of the culture to the petite genotype in one generation. The cells were respiratory active (derepressed) but contained no mitochondrial deoxyribonucleic acid (mtDNA) as demonstrated by analytical ultracentrifugation in CsCl. When transferred to acetate sporulation medium, the culture sporulated. Ascus production was only slightly below that of the control culture. Synthesis of mtDNA occurred during sporulation in the control but not in the EthBr-treated culture. Mitochondrial protein synthesis was virtually eliminated in the EthBr-treated culture. Therefore, completely derepressed cells can sporulate without a functional mitochondrial genetic system. When partially repressed cells were treated with EthBr, no ascus formation was observed after transfer to sporulation medium. Control cultures underwent respiratory adaptation in sporulation medium and then sporulated. Extensive derepression of the respiratory system is thus required for sporulation, and this adaptation is dependent on a functional mitochondrial system. Our results suggest that once the cells are fully derepressed no mitochondrial genetic information has to be expressed during meiosis and ascus formation.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=246527Documentos Relacionados
- A DNA Helicase Required for Maintenance of the Functional Mitochondrial Genome in Saccharomyces cerevisiae
- MGM101, a nuclear gene involved in maintenance of the mitochondrial genome in Saccharomyces cerevisiae.
- Structure and transcription of the mitochondrial genome in heteroplasmic strains of Saccharomyces cerevisiae.
- Heterogeneous Functional Ty1 Elements Are Abundant in the Saccharomyces Cerevisiae Genome
- Isolation and functional analysis of sporulation-induced transcribed sequences from Saccharomyces cerevisiae.
