Localisation of a cDNA clone for human cytokeratin 18 to chromosome 17p11-p12 by in situ hybridisation

Chromosomal mapping of human cytokeratin 13 gene (KRT13)

In the present study the human cytokeratin 13 gene (KRT13), encoding a polypeptide characteristic of internal stratified epithelia, has been mapped with the help of the polymerase chain reaction and somatic cell hybrids to chromosome 17. In situ hybridization of a KRT13 cDNA probe to metaphase chromosomes allowed the assignment of the KRT13 gene within the q12-q21.2 region of chromosome 17.

Regional assignment of the human keratin 5 (KRT5) gene to chromosome 12q near D12S14 by PCR analysis of somatic cell hybrids and multicolor in situ hybridization

Keratin 5 is the major type II keratin of the basal cells of epidermis and of other stratified epithelia. With its type I partner, keratin 14, it constitutes a major fraction of the cytoskeleton of the basal cells. Because the inheritance of epidermolysis bullosa simplex, a disease of epidermal basal cell fragility, was mapped in one family to chromosome 12q close to D12S14, we undertook to localize the gene for keratin 5. Polymerase chain reaction analysis of somatic cell hybrids mapped the keratin 5 gene to chromosome 12, and multicolor fluorescence in situ hybridization localized it to 12q very near D12S14. This sublocalization exemplifies the utility of in situ physical localization in assessing the candidacy of genes thought to underlie inherited disorders.

Human glial fibrillary acidic protein (GFAP): molecular cloning of the complete cDNA sequence and chromosomal localization (chromosome 17) of the GFAP gene

We isolated three glial fibrillary acidic protein (GFAP) cDNA clones from a glioma cell line, U-251 MG. One clone isolated from a U-251 MG cDNA library was long, but lacked both ends. Using poly(A)+ RNA and primers synthesized according to the sequence of this clone, we used the polymerase chain reaction-assisted rapid amplification of cDNA ends (PCR-RACE) method, which is a strategy to isolate cDNA ends, and obtained cDNA clones for the 5' and 3' ends. From the sequences of these overlapping clones, the complete nucleotide sequence of human GFAP cDNA was established. The start (ATG) and the stop (TGA) signals were seen at nucleotide positions 15 and 1311, respectively, and divided the entire sequence of 3027 bp into 14 bp of 5' non-coding, 1296 bp of coding and 1717 bp of 3' non-coding regions. Using cDNA probes made from both the coding and the 3' non-coding regions, Northern blot hybridization was performed with two different stringencies on RNAs from human and rodent brains and human GFAP-positive and -negative cells. It was shown that the 3' non-coding region probe was more specific for human GFAP than the coding region probe which was specific only under higher stringency conditions. This was also suggested by homology analysis of the sequence with those of various intermediate filament proteins. Based on these findings, we performed spot blot hybridization of sorted human chromosomes and Southern blot hybridization of PCR-amplified DNAs of a panel of hamster-human somatic cell hybrids and localized the human GFAP gene to chromosome 17.