A single-base-pair deletion in the beta-glucuronidase gene accounts for the phenotype of murine mucopolysaccharidosis type VII.

Authors

M S. Sands
E H. Birkenmeier

Document Type

Article

Publication Date

1993

Keywords

Amino-Acid-Sequence, Animal, Base-Sequence, Cloning-Molecular, Exons: ge, Frameshift-Mutation: ge, Genome, Glucuronidase: ge, Mice, Mice-Mutant-Strains, Molecular-Sequence-Data, Mucopolysaccharidosis-VII: en, ge, ve, Mutagenesis-Site-Directed, Phenotype, Restriction-Fragment-Length-Polymorphisms, Restriction-Mapping, Rodent-Diseases: ge, Sequence-Analysis-DNA, Sequence-Deletion, Sequence-Homology-Amino-Acid, Sequence-Homology-Nucleic-Acid, SUPPORT-U-S-GOVT-P-H-S, Transfection

First Page

6567

Last Page

6571

JAX Source

Proc Natl Acad Sci U S A 1993 Jul 15;90(14):6567-71

Grant

DK41082/DK/NIDDK, DK07449/DK/NIDDK, DK08546/DK/NIDDK

Abstract

Murine mucopolysaccharidosis type VII is a heritable disease caused by a spontaneous mutation, gus(mps), closely linked to the beta-glucuronidase structural gene on chromosome 5. Mice homozygous for the mutation have a > 200-fold decrease in beta-glucuronidase mRNA levels and virtually no enzyme activity detectable by a sensitive fluorometric assay. Approximately 20 kb of genomic DNA containing the beta-glucuronidase gene Gus and > 2 kb of 5' and 3' flanking sequences were cloned from both a gus(mps)/gus(mps) mouse and a +/+ mouse of the progenitor strain. Restriction enzyme digests containing DNA fragments 20-400 bp in length were generated from each of the two Gus alleles and then compared by using nondenaturing polyacrylamide DNA-sequencing gels. This method rapidly identified a large number of restriction sites and was sensitive enough to detect a restriction fragment length variation resulting from a 1-bp deletion in the gus(mps) allele. DNA-sequence analysis of the mutant genomic fragment showed that the 1-bp deletion created a frameshift mutation within exon 10. Insertion of the deleted nucleotide by oligonucleotide site-directed mutagenesis restored function to the corrected mutant gene when transfected into gus(mps)/gus(mps) fibroblasts. We concluded that the frameshift mutation, which introduces a premature stop codon at codon 497 in exon 10, accounts for the molecular, biochemical, and pathological abnormalities associated with the gus(mps) phenotype.

Recommended Citation

Sands MS, Birkenmeier EH. A single-base-pair deletion in the beta-glucuronidase gene accounts for the phenotype of murine mucopolysaccharidosis type VII. Proc Natl Acad Sci U S A 1993 Jul 15;90(14):6567-71