| Status | Available to order |
| EMMA ID | EM:11297 |
| International strain name | CBA.129S2(B6)-Synbtm2.1Ics/Orl |
| Alternative name | CBA/J Syncytin-B KI |
| Strain type | Targeted Mutant Strains : Knock-in |
| Allele/Transgene symbol | Synbtm2.1Ics |
| Gene/Transgene symbol | Synb |
| Provider | Thierry Heidmann |
| Provider affiliation | Insitut Gustave Roussy, UMR9196 CNRS |
| Genetic information | Mice carrying a mutated copy of the syncytin-B gene (point mutation in the immunosuppressive ISU domain), that abolishes its immunosuppressive activity without altering its fusogenic properties. This strain was obtained via homologous recombination in ES cells. The wild-type syncytin-B gene was replaced by the same gene carrying a K14R point mutation in the ISU domain. This mutation abolishes syncytin-B immunosuppressive activity without altering its fusogenic properties (ref. for the mutation: Mangeney et al, PNAS, 2007, Placental syncytins: Genetic disjunction between the fusogenic and immunosuppressive activity of retroviral envelope proteins). The targeting vector contained a 4.3-kb 5-prime arm and a 5-kb 3-prime arm corresponding to sequences bracketing the syncytin-B ORF, a 2.6 kb fragment containing the syncytin-B unique ORF into which the K14R mutation was introduced (Mangeney et al, PNAS, 2007), and the neomycin resistance (neo) gene. Syncytin-B ORF and neo gene were flanked by FRT and LoxP recombination sites, allowing their conditional excision. In the recombinant mouse strain obtained (EMMA strain ID EM:11297), the frt-flanked neo selection marker was removed by breeding with flp recombinase-expressing mice. The syncytin-B K14R mutant gene is flanked by LoxP recombination sites, allowing its conditional excision. ES cell line used: P1 [MCI-129S2/SvPas] |
| Phenotypic information | Homozygous:No obvious phenotypic defects of homozygous mice (in particular, no placental phenotype). The placentation of these mice could be altered under some particular breeding conditions, due to defects in materno-fetal immune tolerance.Heterozygous:No obvious phenotypic defects of heterozygous mice. |
| Breeding history | The original founder (B6;129S2/SvPas) was backcrossed 10 times to CBA/J. Then, four homozygous mutant siblings, obtained from two couples, were bred and the mutant strain subsequently maintained in a homozygous state for more than 7 generations. |
| References | None available |
| Homozygous fertile | yes |
| Homozygous viable | yes |
| Homozygous matings required | no |
| Immunocompromised | not known |
| Archiving centre | Institut de Transgenose, INTRAGENE, Orléans, France |
| Animals used for archiving | heterozygous CBA |
