{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T16:33:30Z","timestamp":1781109210990,"version":"3.54.1"},"reference-count":0,"publisher":"National Academy of Sciences","issue":"3","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[1984,2]]},"abstract":"<jats:p>Bursal lymphomas induced in chickens by avian leukosis viruses (ALVs) harbor proviral insertions that augment expression of an adjacent cellular oncogene, c-myc. To analyze such insertionally mutagenized c-myc genes in greater detail, we isolated molecular clones from two independent tumors. Precise proviral integration has occurred within the transcribed region of the c-myc gene in both mutant alleles. The proviruses bear different internal deletions that preclude the expression of the gag, pol, and env genes. The c-myc gene from bursal lymphoma LL4 contains a single copy of an ALV long terminal repeat (LTR), presumably the product of homologous recombination between LTRs at the ends of a normal provirus; the \"solo\" LTR is positioned in the correct orientation to act as a promoter for the c-myc gene. Bursal lymphoma LL3 contains an ALV provirus positioned upstream in the opposite transcriptional orientation to the coding exons of c-myc and deleted from a site within the leader region into the gag gene. In addition, the nucleotide sequence of the c-myc gene from tumor LL3 differs from the published sequence of the normal c-myc coding region at 3 positions of 180 determined. One of these changes, a silent nucleotide transition, is documented as a somatic mutation by restriction endonuclease mapping. It is flanked by two other candidate tumor-specific point mutations, one of which predicts an amino acid replacement, Pro----Thr at position 63. Thus, additional lesions that may affect the expression of viral genes and the quantity and nature of the putative c-myc gene product occur in provirally mutated c-myc alleles and may contribute to tumor progression.<\/jats:p>","DOI":"10.1073\/pnas.81.3.843","type":"journal-article","created":{"date-parts":[[2006,5,31]],"date-time":"2006-05-31T05:36:28Z","timestamp":1149053788000},"page":"843-847","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":71,"title":["Proviral deletions and oncogene base-substitutions in insertionally mutagenized c-myc alleles may contribute to the progression of avian bursal tumors."],"prefix":"10.1073","volume":"81","author":[{"given":"D","family":"Westaway","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"G","family":"Payne","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"H E","family":"Varmus","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[1984,2]]},"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.81.3.843","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,4,13]],"date-time":"2022-04-13T11:44:32Z","timestamp":1649850272000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.81.3.843"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1984,2]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1984,2]]}},"alternative-id":["10.1073\/pnas.81.3.843"],"URL":"https:\/\/doi.org\/10.1073\/pnas.81.3.843","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[1984,2]]},"assertion":[{"value":"1984-02-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}