Generation and maintenance of Dmbx1 gene-targeted mutant alleles.
Dmbx1 encodes a paired-like homeodomain protein that is expressed in neural tissues at mouse embryonic and postnatal stages. We previously generated two Dmbx1 mutant alleles, Dmbx1 (-) and Dmbx1 ( z ), by homologous recombination in mouse embryonic stem (ES) cells. In this article we report the generation of three novel Dmbx1 mutant alleles, Dmbx1 (tauZ ), Dmbx1 (tauG ), and Dmbx1 ( Cre ), that carry the intronic insertion of tau (tau)-lacZ, tau-eGFP, and Cre reporter genes, respectively. Dmbx1 (tauZ ) and Dmbx1 (tauG ) recapitulated the Dmbx1 expression, and the reporter gene expression was detected in the diencephalon and mesencephalon during embryogenesis. The crossing of Dmbx1 ( Cre ) mice with Rosa26 reporter mice identified the Cre-mediated DNA excision in the postnatal midbrain, cerebellum, medulla oblongata, and spinal cord. To maintain the Dmbx1 mutant alleles without genotyping, we crossed Dmbx1 mutant mice with Inv4(1) ( Brd ) mice that possess the inversion between D4Mit117 and D4Mit281 on Chromosome 4, where Dmbx1 is located. The intercrossing of the non-agouti (a/a) albino (Tyr ( c-Brd )/Tyr ( c-Brd )) Dmbx1 mutant mice carrying Inv4(1) ( Brd ) tagged with K14-Agouti and Tyrosinase coat-color markers resulted in the generation of dark brown Dmbx1 wild-type [Inv4(1) ( Brd )/Inv4(1) ( Brd )], light brown Dmbx1 heterozygous [Dmbx1 ( tm )/Inv4(1) ( Brd )], and albino Dmbx1 homozygous (Dmbx1 ( tm )/Dmbx1 ( tm )) mutant mice. To our knowledge, this is the first demonstration of the proof-of-principle of the maintenance of viable gene-targeted alleles using coat-color-tagged nonlethal balancer chromosomes.
Ohtoshi
Akihira
A
Center of Molecular and Human Genetics, Children's Research Institute, 700 Children's Drive, Columbus, Ohio 43205, USA. otoshia@pediatrics.ohio-state.edu
Bradley
Allan
A
Behringer
Richard R
RR
Nishijima
Ichiko
I
D000483:Alleles; D000818:Animals; D049452:Green Fluorescent Proteins / Q000235:genetics; D019426:Integrases / Q000235:genetics; D007763:Lac Operon / Q000235:genetics; D051379:Mice; D008817:Mice, Mutant Strains / Q000235:genetics*; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics*; D051857:Otx Transcription Factors / Q000235:genetics*; D012880:Skin Pigmentation / Q000235:genetics
D009419:Nerve Tissue Proteins; D051857:Otx Transcription Factors; C470836:Otx3 protein, mouse; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; C045073:Cre recombinase; D019426:Integrases