{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T15:28:50Z","timestamp":1781105330246,"version":"3.54.1"},"reference-count":0,"publisher":"National Academy of Sciences","issue":"10","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[1990,5]]},"abstract":"<jats:p>The chromosomal fragile-site mapping to Xq27.3 is associated with a frequent form of mental retardation and is prone to breakage after induced deoxyribonucleotide pool perturbation. The human hypoxanthine phosphoribosyltransferase (HPRT) and glucose-6-phosphate dehydrogenase (G6PD) genes flank the fragile X chromosome site and can be used to monitor integrity of the site in human-hamster somatic cell hybrids deficient in the rodent forms of these activities. After induction of the fragile X site, negative selection for HPRT and positive enrichment for G6PD resulted in 31 independent colonies of HPRT-,G6PD+ phenotype. Southern blot analysis demonstrated the loss of all tested markers proximal to the fragile X site with retention of all tested human Xq28 loci in a majority of the hybrids. In situ hybridization with a human-specific probe demonstrated the translocation of a small amount of human DNA to rodent chromosomes in these hybrids, suggesting chromosome breakage at the fragile X site and the subsequent translocation of Xq28. Southern blot hybridization of hybrid-cell DNA, resolved by pulsed-field gel electrophoresis, for human-specific repetitive sequences revealed abundant CpG-islands within Xq28, consistent with its known gene density. The electrophoretic banding patterns of human DNA among the hybrids were remarkably consistent, suggesting that fragile X site breakage is limited to a relatively small region in Xq27-28. These somatic cell hybrids, containing Xq27.3-qter as the sole human DNA, will aid the search for DNA associated with the fragile X site and will augment the high resolution genomic analysis of Xq28, including the identification of candidate genes for genetic-disease loci mapping to this region.<\/jats:p>","DOI":"10.1073\/pnas.87.10.3856","type":"journal-article","created":{"date-parts":[[2006,5,31]],"date-time":"2006-05-31T07:19:43Z","timestamp":1149059983000},"page":"3856-3860","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":34,"title":["Isolation of the human chromosomal band Xq28 within somatic cell hybrids by fragile X site breakage."],"prefix":"10.1073","volume":"87","author":[{"given":"S T","family":"Warren","sequence":"first","affiliation":[{"name":"Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S J","family":"Knight","sequence":"additional","affiliation":[{"name":"Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J F","family":"Peters","sequence":"additional","affiliation":[{"name":"Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"C L","family":"Stayton","sequence":"additional","affiliation":[{"name":"Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"G G","family":"Consalez","sequence":"additional","affiliation":[{"name":"Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"F P","family":"Zhang","sequence":"additional","affiliation":[{"name":"Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[1990,5]]},"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.87.10.3856","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,4,13]],"date-time":"2022-04-13T12:49:12Z","timestamp":1649854152000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.87.10.3856"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1990,5]]},"references-count":0,"journal-issue":{"issue":"10","published-print":{"date-parts":[[1990,5]]}},"alternative-id":["10.1073\/pnas.87.10.3856"],"URL":"https:\/\/doi.org\/10.1073\/pnas.87.10.3856","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[1990,5]]},"assertion":[{"value":"1990-05-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}