Nature Genetics

doi: 10.1038/ng0793-211pmid: 8358424

Bird, Thomas D.

doi: 10.1038/ng0793-213pmid: 8358425

Akhtar, Saghir; Ivinson, Adrian J.

doi: 10.1038/ng0793-215pmid: 8358426

doi: 10.1038/ng0793-217pmid: N/A

In the June issue of Nature Genetics, the addresses for the authors of the News & Views article “Trinucleotide repeat instability: when and where?” were omitted inadvertently. The addresses should have read as follows: David L. Nelson, Institute for Molecular Genetics and Human Genome Center, Baylor College of Medicine, Houston, Texas 77030, USA and Stephen T.

Lannfelt, Lars; Lilius, Lena; Appelgren, Henrik; Axelman, Karin; Forsell, Charlotte; Liu, Li; Johansson, Kurt; Graff, Caroline

doi: 10.1038/ng0793-218pmid: 8358427

McIntosh, Iain; Hamosh, Ada; Dietz, Harry C.

doi: 10.1038/ng0793-219pmid: 8358428

Orr, Harry T.; Chung, Ming-yi; Banfi, Sandro; Kwiatkowski, Thomas J.; Servadio, Antonio; Beaudet, Arthur L.; McCall, Alanna E.; Duvick, Lisa A.; Ranum, Laura P. W.; Zoghbi, Huda Y.

doi: 10.1038/ng0793-221pmid: 8358429

Godfrey, Paul; Rahal, Jason O.; Beamer, Wesley G.; Copeland, Neal G.; Jenkins, Nancy A.; Mayo, Kelly E.

doi: 10.1038/ng0793-227pmid: 8395283

The growth hormone–releasing hormone receptor (GHRHR) is a member of the family of G protein–coupled receptors that is expressed on pituitary somatotrope cells and mediates the actions of GHRH in stimulating growth hormone (GH) synthesis and secretion. We report that the Ghrhr gene is located in the middle of mouse chromosome 6 in the same region as the little mutation. Mice homozygous for this mutation have reduced GH secretion and a dwarf phenotype. A missense mutation was identified in the extracellular domain of the little GHRHR that disrupts receptor function, suggesting that the growth deficit in these mice results from a defect in the GHRHR. Similar alterations in GHRHR might explain some isolated GH deficiencies in humans.

Sabouri, Luc A.; Mahadevan, Mani S.; Narang, Monica; Lee, David S.C.; Surh, Linda C.; Korneluk, Robert G.

doi: 10.1038/ng0793-233pmid: 8358430

Myotonic dystrophy (DM) results from the amplification of an unstable CTG repeat in the 3′ untranslated region of a transcript encoding a putative serine/threonine kinase. We have analysed the amplification of the repeat and the steady state levels of the DM kinase (DMK) mRNA in tissues and cell lines from normal and congenital DM individuals. Southern blot analysis of DNA samples from a severely affected neonate shows somatic heterogeneity of the repeat in all tissues studied. RNA analyses on these tissues show a marked increase in DMK steady state mRNA levels. We demonstrate that the mutant DMK allele is expressed regardless of the number of CTG repeats and that the increase in DMK mRNA levels is due to elevated mutant mRNA levels. We postulate that elevated DMK levels explains the dominant inheritance pattern of DM.

Shinohara, Akira; Ogawa, Hideyuki; Matsuda, Yoichi; Ushio, Noriko; Ikeo, Kazuho; Ogawa, Tomoko

doi: 10.1038/ng0793-239pmid: 8358431

Rad51, of Saccharomyces cerevisiae, is a homologue of recA of Escherichia coli and plays crucial roles in both mitotic and meiotic recombination and in repair of double–strand breaks of DNA. We have cloned genes from human, mouse and fission yeast that are homologous to rad51. The 339 amino acid proteins predicted for the two mammalian genes are almost identical and are highly homologous (83%) with the yeast proteins. The mouse gene is transcribed at a high level in thymus, spleen, testis andpvary and at a lower level in brain and other tissues. The rad51 homologues fail to complement the DNA repair defect of rad51 mutants of S. cerevisiae. The mouse gene is located in the F1 region of chromosome 2 and the human gene maps to chromosome 15.