The spontaneous mutation carried in these mice consists of a large deletion spanning about a 46.7 kb interval that includes the entire sequences of Lrrc75b (AI646023) and Ggt1 and the first exon and part of the first intron of Ggt5.
Ann Davis, Bayer Corporation
The dwarf-Bayer mutation (dwgBayer) occurred spontaneously in an embryonic stem cell line during genetic targeting of the insulin receptor gene. The phenotype of the mice resemble drawf grey (dwg, Stock No. 001743) and subsequent characterization determined that the two mutations are allelic. Homozygous mutant mice are grey and smaller in size than wildtype littermates.
This multigenic deletion occurred in a 129/SvEv ES cell line at Bayer Pharmaceutical Division in West Haven, Connecticut prior to 1995. The ES cell was used for a targeted disruption of a gene on Chromosome 8 and the chimeras generated did not display the dwarf gray phenotype. Four male chimeras were bred to both Black Swiss mice and 129/SvEv females and all of the offspring appeared normal, but when intercrossed the dwarf gray phenotype appeared in the F1 offspring for all four lines, indicating that the mutation derived from the ES cell line. In early 1996 mice at generation F2 or F3 on the 129/SvEv background, with no Black Swiss, were sent to The Jackson Laboratory and bred to C3H/HeSnJ for re-derivation then maintained by sibling inbreeding. The targeted disruption on Chromosome 8 is absent from this line. In 2003 embryos were generated for cryopreservations via in vitro fertilization of heterozygous males and either heterozygous or wildtype females, which were at generation N1F15.
|Allele Name||deletion Chr 10, Bayer 1|
|Allele Synonym(s)||Del(10AI646023-Ggt5)1Bayer; dwarf grey Bayer; dwgBayer; Ggt1dwg-Bayer|
|Gene Symbol and Name||Del(Lrrc75b-Ggt5)1Bayer, deletion Chr 10, Bayer 1|
|Strain of Origin||129S/SvEv|
|Molecular Note||This mutation arose spontaneously in an ES cell line during a targeted mutagenesis experiment for an unrelated gene (insulin receptor). This mutation consists of a large deletion spanning about a 46.7 kb interval that includes the entire sequences of AI646023 and Ggt1 and the first exon and part of the first intron of Ggt5.|