Influence of gene duplication and X-inactivation on mouse mitochondrial malic enzyme activity and electrophoretic patterns.
We have investigated, with and without the influence of X-inactivation, the relationship between autosomal gene-dosage and gene-product in a mammalian system, the mouse. The gene was mitochondrial malic enzyme (Mod-2), shown to lie on Chromosome 7 between the albino (c) and shaker-1 (sh-1) loci, and the enzyme was its product, mitochondrial malic enzyme (MOD-2). Gene duplication, with and without the influence of X-inactivation, was achieved using a translocation that involves the insertion of a portion of Chr 7, including Mod-2, into the X, T(X;7)1Ct. A 1:1 relationship for Mod-2 dosage and MOD-2 activity was found in heart mitochondria. Evidence of X-inactivation of Mod-2 was noted in heart and kidney preparations from females carrying a Mod-2 duplication (one copy of Mod-2 in the X and two copies of Mod-2 on Chr 7). We conclude that the expression of an autosomal locus attached to X-chromatin depends upon whether the translocation is in a balanced or unbalanced state.
D000483:Alleles; D000818:Animals; D002869:Chromosome Aberrations; D002874:Chromosome Mapping; D005260:Female; D008291:Malate Dehydrogenase / Q000096:biosynthesis*; D008297:Male; D051379:Mice; D008931:Mitochondria, Muscle / Q000201:enzymology; D009206:Myocardium / Q000648:ultrastructure; D010641:Phenotype; D014176:Protein Biosynthesis; D012728:Sex Chromatin; D012730:Sex Chromosomes; D014178:Translocation, Genetic
D008291:Malate Dehydrogenase