title: DNA and chromatin structure of the human alpha 1 (I) collagen gene.
abstract: The human alpha 1 (I) collagen gene and 48 kilobase pairs of flanking DNA have been isolated on two overlapping cosmids. The alpha 1 (I) gene is 18 kilobase pairs long and contains a single repetitive element of the Alu family; at least 15 repetitive elements are present in the flanking DNA. Analysis of chromatin structure in nuclei isolated from cultured fibroblasts demonstrated a single chromatin domain greater than 65 kilobase pairs in length that contained 9 DNase I-hypersensitive sites. The pattern of hypersensitive sites was also determined in nuclei derived from placental tissue. Five of the DNase I-hypersensitive sites were observed in both placental and fibroblast chromatin including one site near the 5' end and another near the 3' end of alpha 1 (I). An additional two sites located near the 3' end of the alpha 1 (I) gene in fibroblast chromatin are associated with the tissue-specific use of different polyadenylation sites. Two DNase I-hypersensitive sites found only in fibroblast chromatin and one site found only in placental chromatin were located more than 10 kilobase pairs away from the alpha 1 (I) gene and may be related to tissue-specific expression of other genes in the domain. However, the only abundant placental mRNAs from the 65-kilobase pair domain were those transcribed from the alpha 1 (I) gene. These findings suggest that physical linkage does not play a predominant role in controlling coordinate expression of collagen genes.
mesh_terms: D001482:Base Composition; D001483:Base Sequence; D002478:Cells, Cultured; D002843:Chromatin / Q000378:metabolism*; D003094:Collagen / Q000235:genetics*; D004247:DNA / Q000302:isolation & purification*; D004262:DNA Restriction Enzymes; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D005796:Genes; D006801:Humans; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D002843:Chromatin; D012333:RNA, Messenger; D003094:Collagen; D004247:DNA; D004262:DNA Restriction Enzymes