{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,20]],"date-time":"2025-12-20T21:53:57Z","timestamp":1766267637510},"reference-count":0,"publisher":"Oxford University Press (OUP)","issue":"2","license":[{"start":{"date-parts":[[1979,2,1]],"date-time":"1979-02-01T00:00:00Z","timestamp":286675200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/journals\/pages\/open_access\/funder_policies\/chorus\/standard_publication_model"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[1979,2,1]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n               <jats:p>Neural ganglia of wild type third-instar larvae of Drosophila melanogasier were incubated for 13 hours at various concentrations of BUdR (1, 3, 9, 27 \u03bcg\/ml) . Metaphases were collected with colchicine, stained with Hoechst 33258, and scored under a fluorescence microscope. Metaphases in which the sister chromatids were clearly differentiated were scored for the presence of sister-chromatid exchanges (SCEs) . At the lowest concentration of BUdR (1 \u03bcg\/ml), no SCEs were observed in either male or female neuroblasts. The SCEs were found at the higher concentrations of BUdR (3, 9 and 27 \u03bcg\/ml) and with a greater frequency in females than in males. Therefore SCEs are not a spontaneous phenomenon in D. melanogasier, but are induced by BUdR incorporated in the DNA. A striking nonrandomness was found in the distribution of SCEs along the chromosomes. More than a third of the SCEs were clustered in the junctions between euchromatin and heterochromatin. The remaining SCEs were preferentially localized within the heterochromatic regions of the X chromosome and the autosomes and primarily on the entirely heterochromatic Y chromosome.\u2014In order to find an alternative way of measuring the frequency of SCEs in Drosophila neuroblasts, the occurrence of double dicentric rings was studied in two stocks carrying monocentric ring-X chromosomes. One ring chromosome, C(I)TR94-2, shows a rate of dicentric ring formation corresponding to the frequency of SCEs observed in the BUdR-labelled rod chromosomes. The other ring studied, R(1)2, exhibits a frequency of SCEs higher than that observed with both C(I)TR94-2 and rod chromosomes.<\/jats:p>","DOI":"10.1093\/genetics\/91.2.255","type":"journal-article","created":{"date-parts":[[2021,4,22]],"date-time":"2021-04-22T10:09:04Z","timestamp":1619086144000},"page":"255-274","source":"Crossref","is-referenced-by-count":38,"title":["LACK OF SPONTANEOUS SISTER CHROMATID EXCHANGES IN SOMATIC CELLS OF <i>DROSOPHILA MELANOGASTER<\/i>"],"prefix":"10.1093","volume":"91","author":[{"given":"M","family":"Gatti","sequence":"first","affiliation":[{"name":"Centro di Genetica Evoluzionisfica del C.N.R., Istituto di Genetica, Universit\u00e0 di Roma, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"G","family":"Santini","sequence":"additional","affiliation":[{"name":"Centro di Genetica Evoluzionisfica del C.N.R., Istituto di Genetica, Universit\u00e0 di Roma, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"S","family":"Pimpinelli","sequence":"additional","affiliation":[{"name":"Centro di Genetica Evoluzionisfica del C.N.R., Istituto di Genetica, Universit\u00e0 di Roma, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"G","family":"Olivieri","sequence":"additional","affiliation":[{"name":"Centro di Genetica Evoluzionisfica del C.N.R., Istituto di Genetica, Universit\u00e0 di Roma, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"286","published-online":{"date-parts":[[1979,2,1]]},"container-title":["Genetics"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/academic.oup.com\/genetics\/article-pdf\/91\/2\/255\/34424467\/genetics0255.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"http:\/\/academic.oup.com\/genetics\/article-pdf\/91\/2\/255\/34424467\/genetics0255.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,4,22]],"date-time":"2021-04-22T10:09:05Z","timestamp":1619086145000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/genetics\/article\/91\/2\/255\/5993338"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1979,2,1]]},"references-count":0,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1979,2,1]]}},"URL":"https:\/\/doi.org\/10.1093\/genetics\/91.2.255","relation":{},"ISSN":["1943-2631"],"issn-type":[{"value":"1943-2631","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[1979,2,1]]},"published":{"date-parts":[[1979,2,1]]}}}