International Mammalian Genome Society

17th International Mouse Genome Conference

9-12 November 2003, Braunschweig, Germany

Plenary Presentations * Oral Presentations *
Poster Presentations: Behavioural Genetics and Genomics * Development and Stem Cells * Functional Genome Analysis * Mouse Models of Human Disease * Mouse System Biology Bioinformatics * Multigenic and Multifactorial Trait Analysis * Nutrition and Metabolic Disease * Phenotyping Methods Imaging * The Genetics and Genomics of Infectious Disease *
Verne Chapman Memorial Lecture * Table of Contents * Sponsor/Exhibitor List * Awards * Photographs

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POSTER 116 - IDENTIFICATION OF A NOVEL MOUSE MUSCULAR DYSTROPHY AND DEVELOPMENTAL LIMB DEFECT SYNDROME

Sher R B
The Jackson Laboratory

Co-Authors: Cox G A
Institutions: The Jackson Laboratory

In the course of mapping a C57BL/6J ENU-induced seizure threshold mutation (szt) at the Jackson Laboratory, several mice developed hind limb paralysis resulting from a spontaneous recessive mutation (ym) in the BALB/cByJ mapping partner resulting in a muscular dystrophy and dysmorphic limb development syndrome. Histological analysis revealed malformed ulna and radius in the forelimbs of neo-natal mice, and degeneration and regeneration of muscle fibers in adult mice. Affected ym/ym mice are smaller than their non-affected sibs and display an outward rotation of the forelimbs as early as P6. While the fore limbs remain only mildly affected, the muscular degeneration progresses rapidly in the hind limbs and individuals lose all hind motor control by 3 months of age. The lifespan of mutant mice is not affected despite the impaired motor function. The ym gene has been fine-mapped (>1400 meioses) to a 0.16 cM ± 0.11 cM region of Chromosome 15, corresponding to human 22q13. The 0.5 Mb genomic interval is predicted to contain 22 genes. Putative gene function and expression levels in skeletal muscle based on Realtime PCR have been analyzed for all 22 genes, and several candidate genes have been tested by cloning and sequencing genomic DNA and muscle RNA from affected and wild-type mice. No sequence variations have yet been identified. The development and localization of the disease syndrome is being studied through morphological, ontological, immunohistochemical, and physiological means. Identification of the causative ym gene may contribute to the elucidation of novel dystrophy and limb development pathways.