Rearrangement of a conditional allele regardless of inheritance of a Cre recombinase transgene.
To generate conditional gene knockouts in osteoblasts, we previously developed transgenic mice in which Cre recombinase cDNA was cloned downstream of a 3.6 or 2.3 kb fragment of the rat Col1a1 promoter (Col3.6-Cre and Col2.3-Cre, respectively). Col-Cre mice were bred with mice in which exon 4 of the Igf1 gene is flanked by loxP sites. Mating units were arranged such that either the male or the female breeder transmitted the Col-Cre transgenes. Progeny were evaluated for Cre-mediated Igf1 gene rearrangement. We found that the loxP-flanked Igf1 locus was rearranged in the absence of inheritance of the Cre transgene. The incidence was 50 and 28% with Col2.3-Cre and Col3.6-Cre females, respectively, and 15 and 18% with Col2.3-Cre and Col3.6-Cre males, respectively.
Cochrane
Rebecca L
RL
Department of Medicine, University of Connecticut Health Center, Farmington, Connecticut 06030-1850, USA.
Clark
Stephen H
SH
Harris
Adam
A
Kream
Barbara E
BE
D000483:Alleles; D000818:Animals; D005260:Female; D040582:Inheritance Patterns; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000378:metabolism; D019426:Integrases / Q000235:genetics*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D019076:Transgenes
D007334:Insulin-Like Growth Factor I; C045073:Cre recombinase; D019426:Integrases