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 113 - PHENOTYPIC Characterization AND MAPPING of LITTLE CHIN: an ENU-GENERATED mouse mutant THAT SHOWS CLEFT PALATE AND MICROGNATHIA

Saadi I
Genetics Division, Harvard Medical School, Brigham and Women's Hospital, Boston, MA

Co-Authors: Herron B J, Bjork B C, Lund J J, Maas R L, Beier DR
Institutions: Genetics Division, Harvard Medical School, Brigham and Women's Hospital, Boston, MA

Little chin (lc) was identified in an analysis of E18.5 progeny of ENU-mutagenized mice. Affected mice show a cleft palate and a small jaw with 100% penetrance as well as a frequent occurrence of a split xiphoid process. lc mutants do not nurse upon birth and show perinatal lethality likely due to asphyxiation. Cleft palate and mandibular growth retardation coupled with macroglossia are hallmarks of Pierre-Robin sequence (PRS) seen in humans. Children with PRS birth defects frequently have breathing problems due to airway obstruction. Histological analysis of E18.5 lc embryos also shows narrowing of the airway. At E14.5, the palatal shelves fail to elevate in lc mutants. This elevation defect may be a result of obstruction by the tongue, which also appears malformed at E14.5. The malformation of the tongue, in turn, can be linked to the small mandible. In our efforts to map the lc mutation, we have narrowed down the recombinant interval to a 1.1 Mb region on distal chromosome 14. The interval contains 6 genes, none of which are known to be involved in palatogenesis. Thus, the lc mutant presents a novel mouse model for studying PRS and palatal shelf elevation.