摘要:The results are presented of a special study to determine whether variola-like “whitepox” viruses could arise as white pock variants of monkeypox virus after one or a few mutations. DNA mapping by cross-hybridization of restriction endonuclease DNA fragments was carried out on 18 orthopoxviruses relevant to this study, including variola and monkeypox viruses and white (non-haemorrhagic) pock producers recovered from chorioallantoic membranes infected with red (haemorrhagic) pock-producing monkeypox viruses. The distinctiveness of the DNA maps of true variola and monkeypox viruses indicated that spontaneous production of “whitepox” from monkeypox virus was genetically impossible. These and other observations led to the conclusion that the “whitepox” viruses recovered from monkeypox virus stocks had an exogenous origin. Full text Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.2M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References . 695 696 697 698 699 700 701 702 703