Chromosome segregation is frequently associated with the expression of recessive mutations in mouse cells (adenosine kinase deficiency/toyocamycin/esterase-10 electrophoresis/chromosome analysis)

The genes coding for adenosine kinase (ADK; ATP:adenosine 5'-phosphotransferase, EC 2.7.1.20) and esterase- 10 (ES-10; carboxylesterase, carboxylic-ester hydrolase, EC 3.1.1.1) are both located on chromosome 14 in the mouse. The near-diploid mouse cell line CAK is heterozygous for two electro- phoretic variants of ES-10. Recessive Adk- mutants of CAK have een isolated and analyzed for Es-10 phenotype and karyotypic abnormalities. Two classes of mutants were found with approxi- mately equal frequencies: those that remained heterozygous in the expression of Es- 10 and those that expressed only one Es- 10 allele. Of the mutants that lacked one form of ES-10, approximately half were missing most or all of one copy of chromosome 14; the others contained two copies of 14, frequently in the form of an isochro- mosome. There were no abnormalities of this chromosome found among the mutants that were Es-10 heterozygotes. These results suggest that the expression of an autosomal recessive mutation in near-diploid mouse cells is frequently associated with events that result in the segregation of a physically linked marker and part or all of a chromosome.