| First Author | Smith DL | Year | 1992 |
| Journal | Mouse Genome | Volume | 90 |
| Issue | 3 | Pages | 439-40 |
| Mgi Jnum | J:2530 | Mgi Id | MGI:51052 |
| Citation | Smith DL, et al. (1992) Dopamine D2 receptor RFLP in BXD RIs and assignment to chromosome 9. Mouse Genome 90(3):439-40 |
| abstractText | Full text of Mouse Genome contribution: DOPAMINE D2, RECEPTOR RFLP IN BXD RIs AND ASSIGNMENT TO CHROMOSOME 9. D.L. Smith(1), A.J. Julian(1), V.G. Erwin(2), B.C. Jones(1), M. Chorney(1, 3), G.E. McClearn , and R. Plomin(1). 1Center for Developmental and Health Genetics, The Pennsylvania State University, University Park, PA 16802. 2School of Pharmacy, University of Colorado, Denver, CO 80262. 3Department of Microbiology and Immunology, The Milton S. Hershey Medical Center, Hershey, PA 17033. INTRODUCTION The dopamine D2 receptor (D2dr) gene polymorphism in humans has generated much interest due to its proposed association with alcoholism (1). The inbred mouse strains C57BL/6J (B) and DBA/2J (D) represent opposite extremes in ethanol preference (2), providing a model system for the study of alcohol-related traits. Recently the rat cDNA for D2dr was cloned and sequenced (3). Because the amino acid sequences are identical between rat and mouse for D2dr with 97% homology at the nucleotide level in the coding region (4), the rat D2dr clone was used to probe mouse genomic DNA in order to identify a RFLP polymorphism for B and D and to map the polymorphism using BXD recombinant inbred (RI) strains. MATERIALS AND METHODS Genomic DNA was obtained from Jackson Lab, Bar Harbor, Maine or by standard phenol extraction from liver. DNA was digested according to manufacturer's directions with a twofold excess of restriction enzyme used to ensure complete digestion. Southern blotting was done using alkaline transfer (0.4 N NaOH) onto Cuno Zetabind membrane. Hybridization was carried out overnight at 65 degrees C. RESULTS A Stu I polymorphism, with B band at 9.4 Kb, D bands at 4.6 and 4.8 and constant bands at 0.5, 1.7, and 4.3 Kb, was found for the D2dr locus when the entire 2.4 Kb of the rat clone was used. Enzymes which did not show polymorphism include: Alu I, BamHI, Bcl I, Bg1 II, BstN I, EcoRI, EcoRV, Hind III, Hinf I, Mbo I, Msp I, Pal I, Pst I, Pvu II, Rsa I, Sac I, Sst I, Taq I, and Xba I. The clone was then digested with BamHI and Bgl II and the 1.3 Kb fragment representing the coding portion of the gene (3) was isolated. This fragment also detected the polymorphism while the constant bands at 0.5 Kb and 4.3 Kb were no longer observed. Analysis of the cDNA sequence for mouse D2dr (4) reveals two Stu I restriction sites, at nucleotides 1307-1312 and 1801-1806. These sites are accounted for by the 0.5 and 4.3 Kb bands, however, and are not responsible for the RFLP. Because no other Stu I site occurs in the cDNA sequence, we conclude that the polymorphism must be in an intron. The strain distribution pattern (SDP) for the RFLP differs from SDP reported for more than 555 BXD markers obtained from GBASE, 1992 (5). The most similar BXD SDP occurs for chromosome 9 markers Apoa-1, an anchor locus at 25 cM, and Ncam. The SDP of D2dr in BXD RI and the most similar SDP for chromosome 9 markers are presented in Table 1. Table 1. BXD RI Strain Distribution Pattern for D2dr and Other Chromosome 9 Markers. Apoa-1: BXD RI: 1: B; 2: D; 5: B; 6: D; 8: D; 9: D; 11: B; 12: D; 13: B; 14: D; 15: B; 16: D; 18: D; 19: D; 20: B; 21: D; 22: B; 23: D; 24: D; 25: D; 27: B; 28: B; 29: D; 30: D; 31: B; 32: D; Ref: (6). D2dr: BXD RI: 1: B; 2: D; 5: B; 6: D; 8: D; 9: D; 11: B; 12: D; 13: B; 14: D; 15: B; 16: D; 18: D; 19: D; 20: B; 21: D; 22: B; 23: D; 24: D; 25: D; 27: B; 28: B; 29: D; 30: B; 31: B; 32: D; Ref: (6). Ncam: BXD RI: 1: B; 2: D; 5: B; 6: B; 8: D; 9: D; 11: B; 12: D; 13: B; 14: D; 15: B; 16: D; 18: D; 19: D; 20: B; 21: D; 22: B; 23: D; 24: D; 25: D; 27: B; 28: B; 29: D; 30: B; 31: B; 32: D; Ref: (7). Xmmv-2: BXD RI: 1: B; 2: D; 5: B; 6: B; 8: D; 9: D; 11: B; 12: D; 13: B; 14: D; 15: B; 16: D; 18: D; 19: D; 20: B; 21: D; 22: B; 23: D; 24: D; 25: D; 27: B; 28: D; 29: B; 30: D; 31: B; 32: D; Ref: (8). COMMENTS D2dr in BXD RI mice maps to a position between Apoa-1 and Ncam on chromosome 9. There is one recombination with Apoa-1 and also one with Ncam among 26 RI strains indicating that D2dr is 1.02 cM from both loci with 95% confidence limits of 0.03 and 6.96 cM (9). The human D2dr gene has been mapped to chromosome 11q22-q23 (10) and both Apoa-1 and Ncam in mouse are in a region of chromosome 9 which is syntenic to human chromosome 11q (11). Thus, research linking alcohol-related processes in mice to D2dr may provide a useful model for human alcohol use and abuse. ACKNOWLEDGEMENTS This research was supported by grants from the National Institute on Alcohol Abuse and Alcoholism (AA08125) and the National Institute on Drug Abuse (DA07171). We thank O. Civelli for the D2dr probe, K. Anthony for technical assistance, and R. Hardison for helpful discussion. REFERENCES 1. K. Blum, et al. (1990). JAMA, 263(15): 2055-2060. 2. G.E. McClearn & D.A. Rodgers (1959). Q J of Studies on Alcohol, 20:691-695. 3. J.R. Bunzow, et al. (1988). Nature, 336:783-787. 4. J.P. Montmayeur, et al. (1991). FEBS Letters, 278:239-243. 5. GBASE, the genomic data base for the mouse, maintained at the Jackson Laboratory by D.P. Doolittle, A.L. Hillyard, J.N. Guidi, M.T. Davisson, & T.H. Roderick. 6. E.M. Eicher, et al. (1980). Mol Gen Genet, 177:571-576. 7. C.M. Hearne, et al. (1991). Mammalian Genome, 1:273-282. 8. C. Blatt, et al. (1983). Proc Natl Acad Sci USA, 80:6298-6302. 9. J. Silver (1985). J. Hered., 76:436-440. 10. D.K. Grandy, et al. (1989). Proc Natl Acad Sci USA, 86:9762-9766. 11. J.H. Nadeau (1989). TIG, 3(3):82-86. |
