| First Author | Zwart R | Year | 2001 |
| Journal | Mamm Genome | Volume | 12 |
| Issue | 9 | Pages | 734-40 |
| PubMed ID | 11641723 | Mgi Jnum | J:71414 |
| Mgi Id | MGI:2149931 | Doi | 10.1007/s00335-001-3016-8 |
| Citation | Zwart R, et al. (2001) Genetic analysis of the organic cation transporter genes Orct2/Slc22a2 and Orct3/Slc22a3 reduces the critical region for the t haplotype mutant tw73 to 200 kb. Mamm Genome 12(9):734-40 |
| abstractText | Here we report an analysis of two candidate genes for the tw73 implantation mutation. The tw73 gene maps to a 20-cM region of mouse Chromosome (Chr) 17 known as the t-complex, which exists in a wild-type and t haplotype form in present-day mice. The t haplotype variants contain several mutant alleles affecting male fertility and embryonic viability and offer the opportunity to identify genes critical for these processes. tw73 homozygous embryos are defective in trophoblast production and fail to implant adequately, with death occurring at approximately 7.5 days post coitum (pc). Two recently described organic cation transporter genes, Slc22a2 (Orct2) and Slc22a3 (Orct3), fulfill criteria predicted for tw73 candidate genes, since both map to the previously defined 500-kb tw73 minimal region and both are also expressed in 7.5 days pc post-implantation embryos. The genomic locus of the Orct2 gene appears similar in wild-type and tw73 chromosomes. In contrast, the genomic locus of Orct3 is amplified and displays an altered expression profile in all t haplotype variant chromosomes tested. In addition, Orct3 shows a tw73 specific polymorphism. To test whether either Orct2 or Orct3 is involved in the tw73 phenotype, we have performed a genetic rescue experiment using YAC transgenes overexpressing Orct2, and genetic complementation with an allele in which the Orct3 gene was inactivated by homologous recombination. The results eliminate both Orct2 and Orct3 as candidates and further reduce the critical region containing the tw73 mutant from 500 kb to 200 kb. |
