International Mammalian Genome Society

The 15th International Mouse Genome Conference (2001)

Table of Contents * Complex Genetics * Developmental Genetics * Gene Annotation * Gene Discovery * Genome Sequencing * Functional Genomics * Mutagenesis * Presentations * Verne Chapman Memorial Lecture

Dr Amy Lossie
Baylor College of Medicine
Department of Molecular and Human Genetics
One Baylor Plaza, S411
Houston
77054
USA

Co-Authors: 1)Thomas, SE, 2)O'Day, D, 2)Justice, MJ
Institutions: 1)University of Tennessee, 2)Baylor College of Medicine

Mutagenesis experiments have uncovered 10 lethal complementation groups in the albino complex on mouse Chr 7. One of these, l7Rn3, consists of 6 ENU-induced alleles, 5 of which die in utero. l7Rn3m6/m6 (m6) mutants are viable, although some animals exhibit runting, skeletal defects and mild anemia. In addition, maternal transmission of the m6 mutation in hemizygotes is lethal, suggesting that genomic imprinting plays a role in regulation of l7Rn3. We sequenced a 1 Mb C57BL/6 BAC contig spanning l7Rn3 and found that Odz4 (Odd oz homolog 4) was the only gene in the 500 kb critical region. Odz4, an excellent candidate gene, spans 450 kb of genomic DNA and encodes multiple tissue-specific transcripts. Mutations in the Drosophila homolog exhibit A-P axis defects. Similar phenotypes are seen in the lethal mutants. In the mouse, Odz4 contains 2 putative promoters and poly(A) sites, which encode high levels of transcription in brain and ovary. Additional mRNAs are detected in testes, thymus and skeletal muscle. Sequence analysis of human ODZ4 (11q14) suggests that multiple transcripts are likely, and indicates that ODZ4 may be comprised of 50 exons. So far only 35 exons have been identified from mouse cDNAs. Mutation analysis of Odz4 revealed a missense mutation in the l7Rn3m4 allele. Detection of the m6 mutation should quickly follow. Identification of the m6 defect will further our understanding of the developmental function of Odz4.