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 102 - ALTERNATIVE SPLICING AND TISSUE SPECIFIC EXPRESSION OF Odz4: A CAUSE OF PLEIOTROPIC EMBRYONIC LETHALITY?

A Lossie
Baylor College of Medicine

Justice MJ
Baylor College of Medicine

One of the most important outcomes of the large ENU mutagenesis screens is the creation of an allelic series, where multiple mutations occur in a single gene. When the lesions are identified, the biological functions of the different protein domains become apparent. One of the most mutated loci in the albino region is l7Rn3, with 6 independent mutational events, each of which has a distinct phenotype. The m6 allele has two different phenotypes; it is embryonic lethal when maternally inherited as a hemizygote, but viable when paternally inherited or homozygous. The m6 lethals have primary mesoderm, extraembryonic and neural tube defects. Candidate gene and mutation analyses have identified Odz4 as the best fit for the multiple phenotypes of l7Rn3. Odz4 is a complex locus, spanning =650 kb of genomic DNA and encoding several alternatively spliced transcripts that range in size from 1-12 kb. Two Odz4 cDNAs, totaling 9815 bp, have been isolated from mouse fibroblast and adult brain libraries. Northern analyses show ubiquitous expression of a 4.5 kb transcript, while the 2 and 12 kb mRNAs demonstrate tissue specific expression profiles, with highest levels in the brain and ovary. Intermediate transcripts are also present in ovary, testes, thymus and skeletal muscle. RT-PCR has identified 4 additional brain-specific transcripts and 2 ubiquitously expressed messages. These alternatively spliced products utilize alternate exons. Identification of developmentally regulated and imprinted transcripts is in progress.