International Mammalian Genome Society

logo18th International Mouse Genome Conference

17-22 October 2004, Seattle, USA


Chick WSH 1, Mentzer SE 2, Carpenter DA 2, Rinchik EM 1, You Y 2

1 The University of Tennessee, Knoxville, United States, 2 Oak Ridge National Laboratory, Oak Ridge, United States

Chromosomal inversions and deletions are valuable genetic tools for functional analysis of the genome.  We have used homologous recombination to modify the recessive-lethal In(15)21Rk inversion to endow it with a dominant-visible phenotype.  Several ES-cell lines were derived from inversion heterozygotes, and a keratin-14 (K14) promoter-driven agouti minigene was introduced into the inverted Chr 15 in the ES cells by gene targeting.  Mice derived from the targeted ES cells carry the inverted Chr 15 and at the same time, exhibit lighter coat color on their ears and tails, making this modified In(15)21Rk useful as a balancer for proximal mouse Chr 15.  In order to map the ENU-induced mutations generated by the Neuromutagenesis project of the Tennessee Mouse Genome Consortium, to date we have generated three chromosomal deletion complexes by X-radiation on the distal half of mouse chromosome 15, centered around the Oc90, Sox10 and Cpt1b genes, respectively.  Large deletions spanning up to 5 Mb in ES cells were recovered from around the Sox10 locus whereas mostly small deletions (less than 1 Mb) were recovered from Oc90 and Cpt1b loci. Selected deletions captured in ES cells were injected into blastocysts to produce deletion-bearing mice.  At least 2 deletions at Sox10 transmitted to the germline, and the heterozgyous deletion mice exhibit white spotting in the belly characteristic of Dom mice. Two deletions at Oc90 were also transmitted to germline and the heterozygous deletion mice are outwardly normal. These chromosomal deletion complexes should be useful for mapping mutations and analyzing functional units along the chromosomal regions.

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