Walleye retroviruses associated with skin tumors and hyperplasias encode cyclin D homologs.
Walleye dermal sarcoma (WDS) and walleye epidermal hyperplasia (WEH) are skin diseases of walleye fish that appear and regress on a seasonal basis. We report here that the complex retroviruses etiologically associated with WDS (WDS virus [WDSV]) and WEH (WEH viruses 1 and 2 [WEHV1 and WEHV2, respectively]) encode D-type cyclin homologs. The retroviral cyclins (rv-cyclins) are distantly related to one another and to known cyclins and are not closely related to any walleye cellular gene based on low-stringency Southern blotting. Since aberrant expression of D-type cyclins occurs in many human tumors, we suggest that expression of the rv-cyclins may contribute to the development of WDS or WEH. In support of this hypothesis, we show that rv-cyclin transcripts are made in developing WDS and WEH and that the rv-cyclin of WDSV induces cell cycle progression in yeast (Saccharomyces cerevisiae). WEHV1, WEHV2, and WDSV are the first examples of retroviruses that encode cyclin homologs. WEH and WDS and their associated retroviruses represent a novel paradigm of retroviral tumor induction and, importantly, tumor regression.
Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA.
L A
LA
LaPierre
J W
JW
Casey
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DL
Holzschu
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D056741:Cyclin D; D016213:Cyclins / Q000235:genetics*; D017931:DNA Primers / Q000235:genetics; D005393:Fish Diseases / Q000821:virology*; D005399:Fishes; D005814:Genes, Viral; D005816:Genetic Complementation Test; D006801:Humans; D006965:Hyperplasia; D008969:Molecular Sequence Data; D009365:Neoplasm Regression, Spontaneous; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D012190:Retroviridae / Q000235:genetics* / Q000472:pathogenicity*; D012192:Retroviridae Infections / Q000662:veterinary* / Q000821:virology; D012441:Saccharomyces cerevisiae / Q000235:genetics; D012509:Sarcoma / Q000662:veterinary / Q000821:virology; D017386:Sequence Homology, Amino Acid; D012867:Skin / Q000473:pathology; D012871:Skin Diseases / Q000662:veterinary* / Q000821:virology; D014412:Tumor Virus Infections / Q000662:veterinary* / Q000821:virology
D056741:Cyclin D; D016213:Cyclins; D017931:DNA Primers; D012333:RNA, Messenger; D012367:RNA, Viral