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The Green Monster Process for the Generation of Yeast Strains Carrying Multiple Gene Deletions
Published on: December 15, 2012
Recovery of gene function by gene duplication in Saccharomyces cerevisiae
M L Bach1, F Roelants, J De Montigny
1Laboratoire de Microbiologie et Génétique, URA 1481 Université Louis Pasteur/CNRS, Strasbourg, France.
Yeast (Chichester, England)
|February 1, 1995
Summary
A yeast strain mutation was reverted by a gene duplication event, creating a new functional ATCase locus (dl9) on chromosome X. This rearrangement altered gene expression and chromosome structure.
Area of Science:
- Molecular Biology
- Genetics
- Yeast Genetics
Background:
- Aspartate transcarbamylase (ATCase) is crucial for pyrimidine biosynthesis.
- Mutations in the URA2 gene can lead to ATCase deficiency.
- Prototrophic revertants can arise through complex genetic events.
Purpose of the Study:
- To investigate the genetic basis of a prototroph revertant (Rev9) derived from an ATCase-deficient URA2 mutant.
- To characterize the duplicated ATCase coding sequence (dl9) and its genomic context.
- To understand the chromosomal rearrangement leading to the revertant phenotype.
Main Methods:
- Gene cloning and sequencing of ATCase coding regions.
- Analysis of the 5' end of the duplicated locus (dl9).
- Genomic rearrangement analysis and genetic mapping.
Main Results:
- The revertant Rev9 contains two ATCase coding sequences, with dl9 being the sole functional locus.
- dl9 corresponds to the second half of the wild-type URA2 gene and is inserted near the MRS3 gene.
- A chromosomal rearrangement increased chromosome X size by ~60 kb, with undetectable recombination near dl9.
- Genetic mapping placed the MRS3 gene 2 cM distal to the URA2 gene on chromosome X.
Conclusions:
- A duplication event involving a URA2-derived sequence created a functional ATCase locus (dl9).
- This duplication occurred within an intergenic region, with dl9 transcribed divergently from MRS3.
- The genetic event involved a significant chromosomal rearrangement on chromosome X, impacting local recombination.
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