Genomic Cloning, Physical Mapping, and Expression of Human Type 2 Cystatin Genes
| Autor: | S.J. Millar, L. D. Dempsey, Mary Thiesse, Douglas P. Dickinson |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
0301 basic medicine
Sequence analysis Restriction Mapping Chromosomes Human Pair 20 Gene Expression Locus (genetics) Biology urologic and male genital diseases Chromosome Walking 03 medical and health sciences 0302 clinical medicine Humans Gene family Genomic library Cloning Molecular General Dentistry Genetics Genomic Library Genome Human Chromosome Mapping Sequence Analysis DNA 030206 dentistry Cystatins female genital diseases and pregnancy complications 030104 developmental biology Otorhinolaryngology Cystatin C Cystatin A Cosmid biology.protein RNA Cystatin DNA Probes |
| Zdroj: | Critical Reviews in Oral Biology & Medicine. 4:573-580 |
| ISSN: | 1544-1113 1045-4411 |
| DOI: | 10.1177/10454411930040034401 |
| Popis: | Humans carry one gene encoding cystatin C and six to eight genes with homology to an S-like cystatin hybridization probe. However, the precise composition and organization of the cystatin gene family remains to be established. Further, the pattern of tissue-specific expression has not been fully defined. We have previously shown that the type 2 cystatin genes are clustered together in a ca. 270 kb region (the CST locus). To determine the structure of this region, we have sought to clone the entire CST locus. Our approach has been to isolate cosmid and lambda genomic clones carrying cystatin genes and then to use "walk" probes derived from the end regions of these clones to identify other clones, which extend them. To date, we have obtained over 320 kb of distinct sequences. Based on restriction maps, sequencing, and hybridization analyses, we have identified eight apparently nonallelic copies of cystatin genes. These include one gene for cystatin C, four closely related genes encoding S-like cystatins, and three genes encoding relatively divergent sequences. Complete assembly of these clones into an unambiguous contiguous sequence is hampered by the presence of flanking locus-specific repetitive-like sequences. RNase protection assays used to characterize the tissue-specific patterns of expression showed that cystatin C is expressed at modest, comparable levels in all tissues examined, whereas expression of the CST 1 gene, encoding cystatin SA-I, was found to be restricted to a small subset of tissues, with the highest level in the submandibular gland. The cystatin gene family, therefore, appears to have evolved by tandem gene duplication, followed by the acquisition of control elements influencing the location and level of expression. The cystatin gene family is, thus, a potentially powerful system for the future study of mechanisms of gene regulation in human salivary glands. |
| Databáze: | OpenAIRE |
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