A flexible chemistry for solid phase attachment of oligonucleotides is described. Oligonucleotides bearing 5'-terminal acrylamide modifications efficiently co-polymerize with acrylamide monomers to form thermally stable DNA-containing polyacrylamide co-polymers. Co-polymerization attachment is specific for the terminal acrylamide group. Stable probe-containing layers are easily fabricated on supports bearing exposed acrylic groups, including plastic microtiter plates and silanized glass. Attachment can be accomplished using standard polyacrylamide gel recipes and polymerization techniques. Supports having a high surface density of hybridizable oligonucleotide (approximately 200 fmol/mm2) can be produced.

The SNF2 and SNF5 genes are required for derepression of SUC2 and other glucose-repressible genes of Saccharomyces cerevisiae in response to glucose deprivation. Previous (28). The SUC2 gene encodes these two invertases by producing two differently regulated mRNAs: a glucose-repressible, 1.9-kilobase (kb) mRNA that encodes secreted invertase, and a constitutive, 1.8-kb mRNA with a different 5' end that encodes an intracellular invertase (7,11,25). Previous studies have identified an upstream regulatory region that is required for transcription of the 1.9-kb mRNA (28) and able to confer glucose-repressible expression to the heterologous promoter of a LEU2-lacZ gene fusion (29).We have previously isolated mutations in trans-acting genes necessary for sucrose utilization (9, 22). These recessive mutations fell into six complementation groups SNFJ through SNF6 (sucrose nonfermenting); a mutation in any one of these genes partially or completely blocks derepression of the SUC2 gene. Genetic analysis has suggested that the SNF2 and SNF5 genes play functionally related roles in derepression of SUC2. The interactions of these mutations with suppressor mutations at the SSN6 and SSN20 loci * Corresponding author.clearly distinguish snf2 and snf5 from snfl, snJ3, and snf4 (22,23). It is likely that SNF6 is also functionally related to SNF2 and SNF5, as judged by the interactions of our one, possibly leaky, snf6 mutation with ssn6 and ssn20.Two mutant alleles of both snJ2 and snpf have been isolated, including a nonsense allele of each (22). These snJ2 and snf5 mutants are unable to derepress secreted invertase to normal levels, but produce a small percentage of the wild-type activity under derepressing conditions. This defect results in an inability to utilize raffinose for growth; however, the low level of derepression is still sufficient to allow growth on sucrose. These results suggest that low-level regulated expression of SUC2 can occur in the absence of functional SNF2 or SNF5 gene product, but it is possible that neither nonsense mutation is truly a null mutation. The mutants also exhibit pleiotropic defects in utilization of galactose, maltose, and nonfermentable carbon sources, which are also regulated by glucose repression, and grow more slowly than the wild type on glucose. In addition, snf2 and snp homozygous diploids are unable to sporulate.In

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