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. 1990 Sep;126(1):53–62. doi: 10.1093/genetics/126.1.53

Mobility of Two Optional G + C-Rich Clusters of the Var1 Gene of Yeast Mitochondrial DNA

J M Wenzlau 1, P S Perlman 1
PMCID: PMC1204136  PMID: 2227389

Abstract

Yeast mtDNA contains two different kinds of mobile optional sequences, two group I introns and a short G + C-rich insertion to some var1 genes. Movement of each element in crosses has been called gene conversion though little is known about the mechanism of G + C cluster conversion. A new allele of the var1 gene found in mtDNA of Saccharomyces capensis is described that permitted a more detailed comparison between intron mobility and G + C cluster conversion. The S. capensis var1 gene lacks the cc(+) element present in all S. cerevisiae var1 genes and the previously described optional a(+) element. In crosses with cc(+) a(-) and cc(+) a(+) S. cerevisiae strains, both clusters were found to be mobile and, in the latter cross, appear to convert independently and only to homologous insertion sites. No evidence for flanking marker coconversion (a hallmark feature of intron conversion) was obtained despite the availability of nearby physical markers on both sides of cluster conversion sites. These data indicate that G + C cluster conversion has only a superficial resemblance to intron mobility; analogies to procaryotic transposition mechanisms are considered.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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