Unformatted text preview: l-to-cell communication.
Once the yeast genome sequence became available, it
was possible to create deletion mutations in each of the
over 6000 ORFs and test the effects of the mutations. Deletion mutants were generated by PCR synthesis of fragments containing 25 bases from the beginning and end of
each ORF, with a KANR gene acting as a selectable marker
between the beginning and ending pieces of the gene. After
transformation of these linear fragments into cells, the
DNA integrated by homologous recombination. This very
valuable collection of deletion mutants is now available to
all researchers, who can use it to search for mutations in
their favorite process. In one study, researchers assayed the
effect of each deletion mutation (null mutation) in both
haploids and diploids. From this analysis, they found that
80% of yeast genes appeared to be non-essential.
How can yeast tolerate so many individual deletions?
One hypothesis is that there is redundancy of function in
the genome, with gene products that work in different pa...
View Full Document
- Spring '08
- DNA, MAT locus, Yeast Geneticist