title: [Study on gene-dosage effect of high level expression of the yeast glucoamylase genes].
abstract: Diploid strains homozygous for both MAT allele and STA genes (a/a, STA1/STA1 or STA2/STA2 or STA3/STA3) and diploid strains homozygous for MAT allele but intercombinative for STA genes (a/a, STA1/STA2 or STA2/STA3 or STA1/STA3) were constructed by means of the protoplast fusion or the colchicine treatment. According to glucoamylase activity in YPS medium, we studied the gene-dosage effect and their interrelation of these three polymeric genes coding for glucoamylase. The results of the glucoamylase activity determination showed that the gene-dosage effect of glucoamylase is obvious in diploid and triploid strains homozygous for both MAT allele and STA gene, such as the glucoamylase activity of a diploid strain SFY56-6 and a triploid strain SFY56-104 homozygous for both MAT allele and STA genes were respectively 2.35 and 3.18-fold as compared with that of the their parental strain IATA-Y56 that is a haploid Saccharomyces diastaticus. Moreover, the glucoamylase activity of diploid strains homozygous for MAT allele but intercombinative for STA genes also showed the combinative gene-dosage effect to a certain extent.
authors.affiliation: College of Life Science, Zhejiang University, Hangzhou.
authors.forename: C L
authors.initials: CL
authors.lastname: Li
authors.forename: T S
authors.initials: TS
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Zhang
authors.forename: J Z
authors.initials: JZ
authors.lastname: Li
authors.forename: S Y
authors.initials: SY
authors.lastname: Chen
mesh_terms: D018628:Gene Dosage; D005087:Glucan 1,4-alpha-Glucosidase / Q000235:genetics*; D012440:Saccharomyces / Q000201:enzymology / Q000235:genetics*
chemical_list: D005087:Glucan 1,4-alpha-Glucosidase