Cell-type-specific cDNA probes and the murine I region: the localization and orientation of Ad alpha
Labeled cDNA probes highly enriched for B-cell-specific (B-T) and T-suppressor-cell-specific (Ts-B) sequences were used to screen a set of genomic cosmid clones spanning 230 kilobases of the murine immune response (I) region. With the B-cell derived probe, four I-region genes were detectable (A beta, E beta, E beta 2, and E alpha), as well as an additional (fifth) region of hybridization. The T-cell probe, prepared from a putative I-J positive suppressor cell hybridoma, was negative in a parallel experiment. A genomic fragment corresponding to the new region of hybridization seen with the B-cell cDNA probe identified a discrete mRNA species in RNA blotting analysis that had a pattern of expression strikingly similar to E alpha mRNA in a variety of lymphoid tumor lines. This fragment was also used to isolate cDNA clones from a library highly enriched (20-40 times) for B-cell-specific sequences (selected cDNA cloning). DNA sequence analysis of one of these cDNA clones indicates that this gene encodes the A alpha molecule of the d haplotype (Ad alpha). These findings establish that the order of the class II genes in the Ia complex is as follows: centromere-A beta-A alpha-E beta-E beta 2-E alpha.
Additional Information© 1984 by the National Academy of Sciences. Contributed by William E. Paul, January 3, 1984. We thank Dr. Anthony Defranco for providing LPS-stimulated Wehi 231 mRNA and Drs. Ronald Germain, Stephen Hedrick, and Anthony Defranco for critical reading of the manuscript. M.M.D. was supported by National Science Foundation and National Institutes of Health Fellowships. D.C. is a Fellow of the Leukemia Society of America, and M.S. was supported by the California Division of the American Cancer Society. The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.
Published - DAVpnas84.pdf