Relative to avian and mammalian model systems that have been
established to study retrovirus-induced oncogenesis, very little
is known about the retroviruses that induce neoplasia in fish.
We recently cloned the DNA genome of WDSV from unintegrated DNA
in tumor tissue . The size of the DNA, ca. 13 kB, placed WDSV
genome among the largest known, similar to the genomes of spumaviruses
. The unintegrated DNA in tumors was shown to have a region susceptible
to single-strand specific nucleases (sometimes referred to as
a "gap" structure) , a feature common to spumaviruses
and some lentiviruses . The presence of short transcripts in
tumor tissues suggested that WDSV encodes accessory proteins,
as do all the members of the three retrovirus genera typified
by human spumaretrovirus (HSRV, spumaviruses), human immunodeficiency
virus (HIV1, lentiviruses), and human T-cell leukemia virus (HTLV
and bovine leukemia viruses). As a first step to characterizing
the properties of WDSV that may contribute to induction and subsequent
regression of tumors, we have sequenced a full length DNA clone
of WDSV and analyzed the major virion proteins.
References:
Martineau, D., R. Renshaw, J.R. Williams, J.W. Casey, and
P.R. Bowser. 1991. A large unintegrated retrovirus DNA species
present in a dermal tumor of walleyes. Diseases of Aquat. Organisms.
10:153-158.
Martineau, D., R. Renshaw, P. R. Bowser, and J. W. Casey.
1991. Initial characterization of a retrovirus found in walleyes
(Stizostedion vitreum). Second International Symposium
of Virus of Lower Vertebrates. Oregon State University Printing
Department, Corvallis, OR pp. 157-163.
Martineau, D., P.R. Bowser, R.R. Renshaw and J.W. Casey.
1992. Molecular characterization of a unique retrovirus associated
with a fish tumor. J. Virology 66:596-599.
Holzschu, D.L., D. Martineau, S.K. Fodor, V.M. Vogt, P.R.
Bowser and J.W. Casey. 1995. Nucleotide sequence and protein
analysis of a complex piscine retrovirus, walleye dermal sarcoma
virus. Journal of Virology 69:5320-5331.
Quackenbush, S.L., D.L. Holzschu, P.R. Bowser, and J.W. Casey.
1997. Transcriptional analysis of walleye dermal sarcoma virus
(WDSV). Virology. 237:107-112.
