E. Boyd

Regional chromosomal assignment of the human glucocorticoid receptor gene to 5q31

SummaryThe gene for the human glucocorticoid receptor, previously mapped to chromosome 5, has been further localised to 5q31 by in situ hybridisation using a biotinylated 4.3-kb cDNA probe.

Regional chromosomal assignment of the human mineralocorticoid receptor gene to 4q31.1

SummaryThe gene for human mineralocorticoid receptor (hMR), previously mapped to chromosome 4, has been further localized to 4q31.1 by in situ hybridization using a biotinylated 3.75kb human cDNA clone encoding the primary amino acid sequence of hMR as a probe. Preliminary comparative mapping studies in orangutan (Pongo pygmaeus) suggest localization of the probe to the long arm of chromosome 3.

Regional assignment of the human C1-inhibitor gene to 11q11-Q13.1

SummaryIn situ hybridisation using a biotinylated 1.8kb human cDNA clone in both normal and structurally abnormal chromosomes supports regional localisation of the gene for human C1-inhibitor to chromosome 11q11-q13.11.

Regional chromosomal assignment of genes encoding the α and β subunits of human complement protein C8 to 1p32

SummaryThe genes encoding the α and β subunits of human complement protein C8 previously mapped to chromosome 1 have been further localised to 1p32 by in situ hybridisation using biotinylated 2.4-kb human cDNA clones encoding the α and β subunits of human complement protein C8 as probes.

Regional chromosomal assignment of human 3-beta-hydroxy-5-ene steroid dehydrogenase to 1p13.1 by non-isotopic in situ hybridisation

SummaryIn situ hybridisation using a biotinylated 1.2-kb human cDNA clone for human 3-beta-hydroxy-5-ene steroid dehydrogenase (HSD) supports the provisional regional localisation of the HSD gene to chromosome 1p13 and refines this localisation to 1p13.1.

Assignment of the gene encoding the human thyrotropin-releasing hormone receptor to 8q23 by fluorescence in situ hybridization

A cDNA for human thyrotropin-releasing hormone (TRH) receptor has been isolated from a human pituitary cDNA library. By using this cDNA as a biotinylated probe, the gene encoding the TRH receptor has been localized to chromosome 8q23 by in situ hybridization.

Regional chromosomal assignment of the Kell blood group locus (KEL) to chromosome 7q33-q35 by fluorescence in situ hybridization: evidence for the polypeptide nature of antigenic variation

The gene encoding the Kell blood group polypeptide has been localized to chromosome 7q33-35 by in situ hybridization using a biotinylated 1.1-kb DNA fragment containing the 3′ half of the human cDNA. This assignment is in accord with genetic localization using antigenic variation as a marker, and strongly suggests that Kell antigenic determinants are part of the polypeptide chain rather than the associated sugar molecules.

Assignment of the gene encoding the human gonadotropin-releasing hormone receptor to 4q13.2-13.3 by fluorescence in situ hybridization

The gene encoding the gonadotropin-releasing hormone receptor has been localised to chromosome 4q13.2-13.3 by in situ hybridization using a biotinylated cDNA probe.

Regional chromosomal assignment of the human platelet phosphofructokinase gene to 10p15

SummaryA cDNA for human platelet 6-phosphofructokinase (PFKP) has been isolated from a human Raji cell line cDNA library. Using this cDNA as a probe, the gene for human PFKP, previously mapped to chromosome 10pter-p11.1, has been further localized to 10p15 by non-isotopic in situ hybridization.

New members of the 3β-hydroxysteroid dehydrogenase gene family

Several bands of hybridization are detected when southern blots of human genomic DNA are probed with cDNA of 3 β -hydroxysteroid dehydrogenase (3 β -HSD) type I. Two experimental approaches were adopted to estimate the size of the 3 β -HSD gene family. Firstly, primers designed to amplify 3 β -HSD type I and II genes were found on occasion to amplify DNA products of appropriate length but which were resolved as distinct sequences by denaturing gradient gel electrophoresis (DGGE). Five of these novel bands were cloned and their sequences were found to be closely related to 3 β -HSD types I and II. Secondly, 57 genomic clones were selected from two λ genomic libraries by hybridization with exonic probes of 3 β -HSD type I. These were screened for novel members of the gene family by PCR amplification using various combinations of PCR primers to the type I and II genes, particularly those primers that previously amplified. novel PCR products from genomic DNA. Amplification products from λ clones were screened for novel sequences by DGGE. As a result of these approaches, at least five new members of the 3 β HSD gene family were found, one of which locates to the 3 β -HSD type I and II gene cluster on 1p13. The existence of additional closely related but distinct members of the gene family should be recognized as a potential complication when screening PCR fragments for mutations in the type I and II genes. DGGE was found to be an exceedingly rapid means of screening amplification products from λ clones to search for novel members of the gene family.