International Mammalian Genome Society

The 16th International Mouse Genome Conference (2002)

Plenary Presentations * Oral Presentations *
Poster Presentations: Complex Genetics and Disease Modifiers * Developmental Genetics * Functional Genomics * Gene Discovery * Genetic Manipulations to Alter Gene Function * Mouse Models: Human Disease and Pharmacogenetics * Sequence Annotation and Comparative Analysis of Genomes *
Attendees * Sponsors * Table of Contents * Photographs * Awards

POSTER 112 - ANALYSIS OF ENU(N-ethyl-N-nitrosourea)-INDUCED MYOTONIA MOUSE

CW Song
Korea Institute of Toxicology

1) Kim EM, 2) Cho JW, 2) Cho KH, 2) Kim YE, 1) Kim Yoon S, 3) Paik NJ, 2) Han SS
1) Research Institutes of Medical Sciences, Catholic University of Korea, Seoul, 2) Mutant Mouse Development Laboratory, Korea Institute of Toxicology, Korea Research Institute of Chemical Toxicology, 3) Seoul National University College of Medicine, Korea

Abnormal mice exhibiting muscular stiffness, delayed righting response, axial skeleton of S-shape, and low weight at the adult stage were identified in ENU recessive behavior screen. There were no lesions like degeneration and necrosis. However, the reduction of muscle size and the typical myotonic EMG wave were observed in muscle tissues. The myotonia symptom was progressive especially between 1~3 months of age. For the inheritance confirmation and the genetic mapping, the male BALB/c myotonia carrier was outcrossed to normal female C57BL/6, and the F1 mice were intercrossed (F1x1). Affected animals were detected only in F2 but not F1. The segregation ratio in BALB/c background and hybrid line was 254:76 and 178:50 respectively  without sex differences. Therefore, This mutation mode was autosomal recessive. The causative gene was mapped about 25cM from centromere of chromosome 6 using microsatellite markers. That was 2.86 and 7.14cM away from D6MIT223 and D6MIT268 respectively. Comparing phenotype and candidate gene locus with those of ADR mouse, we thought of a candidate gene as clc1. The mutation analysis was performed through RT-PCR of total RNA from the femoral muscle of mutant and sequencing of PCR products. Sequence comparison between affected and normal mice revealed amino acid change from valine to alanine in CLCN1 protein resulting from the single nucleotide change T1919C. This mouse will be a good model to present new insight in function of CLCN1.