title: Alternative use of 5' exons in the specification of Ly-5 isoforms distinguishing hematopoietic cell lineages.
abstract: Previous inferences that Ly-5 glycoprotein isoforms of murine hematopoietic cells are generated by alternative splicing of primary transcripts of a single Ly-5 gene are supported by the present study. A cDNA library was prepared from B cells by extension from primer representing a known T-cell cDNA sequence. Three different Ly-5 clones from this library included sequences missing in T-cell cDNA clones. From the constitution of cDNA clones and of the Ly-5 gene, and from S1 nuclease mapping, it is concluded that at least two exons, provisionally numbered Ex-6(B) and Ex-7(B), in the 5'-proximal region are mainly represented in mRNA of the B-cell lines examined but not of the T-cell lines examined. Also, exons 1 and 2 appear to be used alternatively in different species of B-cell mRNA and probably also in different species of T-cell mRNA.
mesh_terms: D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000032:analysis; D004720:Endonucleases / Q000378:metabolism; D006410:Hematopoiesis; D006649:Histocompatibility Antigens / Q000235:genetics*; D017493:Leukocyte Common Antigens; D051379:Mice; D012326:RNA Splicing; D015719:Single-Strand Specific DNA and RNA Endonucleases; D014158:Transcription, Genetic
chemical_list: D006649:Histocompatibility Antigens; D004247:DNA; D004720:Endonucleases; D017493:Leukocyte Common Antigens; D015719:Single-Strand Specific DNA and RNA Endonucleases