These SMN2; Smn; HSA69-SMN mutant mice harbor a targeted mutation and two trangenes, all independently created.
The Smn1tm1Msd targeted mutation was created in the laboratory of Dr. Michael Sendtner at the University of Wurzburg, Germany. Exon 2 of the targeted gene was disrupted with a neomycin cassette and a lacZ gene (fused to the first 40 nucleotides of the disrupted exon to permit expression of the lacZ gene in tissues where Smn is normally expressed). The construct was electroporated into 129P2/OlaHsd-derived E14Tg2a-IV embryonic stem (ES) cells. Chimeric animals were crossed to C57BL/6 for an unspecified number of generations.
The HSA-SMN transgene was designed with the human alpha-skeletal actin (HSA or ACTA1) promoter region, splice acceptor site from the SV40 VP1 intron, full-length humsn SMN cDNA (containing exons 1-8), and two SV40 polyA signals. This transgene was microinjected into fertilized FVB/N oocytes. Mice from founder line 69 (HSA69-SMN) were found to have 11 copies of the transgene.
The SMN2 transgene was created in the laboratory of Dr. Arthur Burghes at The Ohio State University. A 35.5 kb BamHI genomic fragment encoding the human SMN2 promoter and gene (derived from genomic clone PAC215P15) was injected into fertilized FVB/N mouse oocytes and founder animals obtained. Transgenic SMN2 mice from founder line 89 were established and found to contain one copy of the transgene (also called SMN2 low copy line 89).
To generate the SMN2; Smn; HSA69-SMN mutant strain, FVB/N SMA carrier mice (heterozygous for the Smn1tm1Msd targeted mutation and homozygous for the SMN2 low copy line 89 transgene and backcrossed to FVB/N for at least 5 generations) were bred with FVB/N HSA69-SMN mice. Mice heterozygous for the targeted mutation, heterozygous for the HSA69-SMN transgene, and homozygous for the SMN2 low copy line 89 transgene were maintained for many generations prior to arrival at The Jackson Laboratory.
