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 20 - THE EFFECT OF THE GTROSA26 INSERTION ON SUSCEPTIBILITY TO MAMMARY AND INTESTINAL TUMOR DEVELOPMENT IN ApcMin/+ Mice

A Moser
University of Wisconsin

Kohlhepp R, Hegge L
1) University of Wisconsin

Approximately 5% of C57BL/6J (B6) female mice heterozygous for ApcMin (Min), a nonsense mutation at codon 850 of the murine Apc locus, develop spontaneous mammary tumors.  Treatment with ethylnitrosourea (ENU) results in about 90% of B6 Min/+ females developing multiple mammary tumors within 65 days.  However, B6 Min/+ mice carrying the Gtrosa26 gene-trap insertion on chromosome 6 are resistant to mammary tumor development.  We have found that two independently derived congenic lines of B6 ROSA26 mice carry more than 25 cM of DNA from the 129 strain flanking the insertion.  To map the locus affecting mammary tumor development within this region, we identified and characterized several lines of mice carrying smaller sections of the congenic region.  Only the mice carrying a congenic interval containing the Gtrosa26 insertion are resistant to mammary tumor development.  The Gtrosa26 insertion also affects intestinal tumor growth, but not multiplicity.  We have further shown that the Gtrosa26 insertion has an effect on the development of normal mammary glands in pre-pubertal mice, and an effect on the normal growth of mice.