Department of Microbiology and Immunology


Walleye Dermal Sarcoma Project

Overview
The Aquatic Animal Health Program has actively investigated tumors of aquatic animals with retroviral etiologies or suspect retroviral etiologies since 1985. This Web Site provides an overview of the Walleye Dermal Saracoma Project. The walleye dermal sarcoma system is of particular interest because it is a tumor system where the lesion develops and regresses on a seasonal basis. Or overall objective is to determine the mechansism(s) of this seasonality.


History
Personnel
Seasonal Prevalence
Experimental Transmission
Experimental Transmission and Water Temperature
Molecular Cloning of the Virus
Regression of the Tumors
Experimental Transmission and Age of Fish and Route of Challenge
Epizootiology in Feral Fish in Oneida Lake
References

 

History
For a number of years, staff of the New York State Department of Environmental Conservation Oneida Fish Hatchery, Oneida Lake, Constantia, New York have observed a number of skin lesions on walleyes during the spring spawning activities at the hatchery. The sport fishing public also observed skin tumors on walleyes during the winter, during ice fishing, an during the early spring. Few, if any, skin tumors were observed on Oneida Lake walleyes during the late spring, summer or early fall. The first descriptions of these skin tumors were made by Dr. Roland Walker of Rensselaear Polytechnic Institute, Troy, New York. Similar skin lesions on walleyes were also reported in populations found in the prairie provinces of Canada. In both Oneida Lake and Canada, descriptions of retrovirus-like particles were presented.

Our laboratory group became interested in these tumors because they appeared to be viral caused neoplasitic diseases that developed and regressed on a seasonal basis. Our initial effort was to confirm the seasonal nature of the lesions through the conduct of a seasonal prevalence study on Oneida Lake. Our next effort was to develop a laboratory-based transmission model. Such a model would allow us to study the pathogenesis of these diseases under controlled conditions. Finally, we have used our transmission model to investigate the basic mechanisms that result in the seasonal development and regression of the lesions. Our long-term objective is to utilize these diseases as models for understanding pathogenesis of neoplasms and retroviral diseases. An understanding of how these diseases behave in fish may shed light on how they may be controlled in other host species, including man.

Reference:

Bowser, P.R., M.J. Wolfe, J.L. Forney, and G.A. Wooster. 1988. Seasonal prevalence of skin tumors from walleye (Stizostedion vitreum) from Oneida Lake, New York. J. Wildl. Dis. 24:292-298.

 

Personnel
Dr. Paul R. Bowser
Professor of Aquatic Animal Medicine
Experetise: Fish Diseases, Fish Pathology, Health Management of Intensively Cultured Aquatic Animals

Dr. James W. Casey
Associate Professor of Virology
Expertise: Virology, Oncology

Dr. Volker M. Vogt
Professor of Virology
Expertise: Virology, Protein Chemistry

Gregory A. Wooster
Research Support Specialist
Expertise: Fish Health Management

Rodman G. Getchell
Research Support Specialist
Expertise: Fish Health Management

Rufina Casey
Research Technician
Expertise: Biochemistry, Molecular Biology


Seasonal Prevalence
A seasonal prevalence study of proliferative skin lesions was conducted on walleyes found in Oneida Lake in 1986. Fish were examined during the spring spawning activities at the New York State Department of Environmental Conservation Oneida Fish Hatchery, Oneida Lake, Constantia, New York in April. Through the remainder of the season, samples were collected with the assistance of the staff of the Cornell University Biological Field Station, Oneida Lake, Bridgeport, New York. Oneida Lake walleyes were examined during the ice-free period of the year. Prevalence data for four different skin lesions were collected. Two of these lesions has proposed retroviral etiologies at the time: walleye dermal sarcoma and discrete epidermal hyperplasia. One lesion, diffuse epidermal hyperplasia, had a proposed herpesvirus etiology. Lymphocystis (a cell hypertrophy), the fourth lesions has an iridovirus etiology.

Prevalence of all lesions was found to be high in the spring, low in the summer and high in the fall. In addition, the tumors appeared to be rare on the youngest fish, based on size of fish on which lesions were found. Walleyes do not join the spawning run until they are approximately 3+ years-old. No lesions were observed on fish less than 300 mm total length. The relationship of age of fish to presence of lesions was further investigated in later years when prevalence of lesions by year class was investigated.

Reference:

Bowser, P.R., M.J. Wolfe, J.L. Forney, and G.A. Wooster. 1988. Seasonal prevalence of skin tumors from walleye (Stizostedion vitreum) from Oneida Lake, New York. J. Wildl. Dis. 24:292-298.

 

Experimental Transmission
Cell-free filtrates from tumors collected from adult walleyes during the spring spawning run were used in the initial attempt at experimental transmission of walleye dermal sarcoma to young-of-the-year (age 0+) walleyes. The fish were maintained in the laboratory in water at 10C. Fish received an intramusacular injection of cell-free tumor filtrate into he hypaxial muscle. Tumors were not observed grossly, but were observed in fish following histological evaluation of skin biopsies.

Reference:

Martineau, D., P.R. Bowser, G.A. Wooster and L.D. Armstrong. 1990. Experimental transmission of a dermal sarcoma in fingerling walleyes (Stizostedion vitreum vitreum). Vet. Pathol. 27:230-234.

 

Experimental Transmission and Water Temperature
A transmission trial was conducted to determine if there was a temperature effect on transmission of walleye dermal sarcoma in young-of-the-year walleyes. Cell-free filtrates were prepared from tumors collected from adult fish in the spring. The laboratory-based transmission model was conducted at 10, 15, and 20C. Fish received an intramuscular injection in the right epaxial muscle. Grossly visible dermal sarcomas were observed as early as 8 weeks post-challenge in fish held at 15C and 20C. Tumors were observed in fish maintained at 10C only with the aid of histological examination. Prevalence of walleye dermal sarcoma was greatest in fish challenged at 15C, followed by that at 20C and 10C.

Reference:

Bowser, P.R., D. Martineau, and G.A. Wooster. 1990. Effects of water temperature on experimental transmission of dermal sarcoma in fingerling walleyes (Stizostedion vitreum). J. Aquat. Animal Health 2:157-161.

 

Molecular Cloning of the Virus
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.

 

Regression of the Tumors
Observations of dermal sarcoma prevalence in wild populations suggested that tumor-positive fish lost their tumors during the period of spring to summer. This hypothesis was reached based on the fact that large numbers of adult walleyes (20-30%) were tumor-positive during the spring spawning run each April and very few tumor-positive fish could be found in the summer months. Populations dynamics studies of walleye populations on Oneida Lake conducted by the Cornell University Biological Field Station did not indicate that massive die-offs occurred during this period. In addition, during the spring spawning run, many walleye dermal sarcomas appeared grossly necrotic and could be easily dislodged from the fish. To better document this apparent regression, tumor-positive walleyes collected from Oneida Lake were identified with individually numbered jaw tags. These fish were transported to experimental ponds near the Cornell University campus in Ithaca, NY, in April. When the fish were inventoried in July of the same year, many of the previously tumor-positive fish had no tumors. This provided difinitive evidence that the tumors actually regressed during the period of spring to summer.

Reference:

Bowser, P.R. and G.A. Wooster. 1991. Regression of dermal sarcoma in adult walleyes (Stizostedion vitreum). J. Aquat. Animal Health. 3:147-150.

 


Experimental Transmission and Age of Fish and Route of Challenge
The laboratory-based transmission model was used to investigate the effect of age experimental transmission of walleye dermal sarcoma. All previous transmission trials had been performed with 12-week old fish. The experimental design encorporated the use of 6-, 8-, 12-week-old, and 1 year-old fish. Walleye dermal sarcoma became invasive in fish challenged at 6- and 8-weeks of age. This was the first known malignant behavior of walleye dermal sarcoma. In all previous investigations with feral fish and in laboratory experiments, walleye dermal sarcoma remained superficial in nature and was considered to be a benign neoplasm.

It is likely that transmission in feral populations occurs by a topical route of exposure. During the spring spawning run, large numbers of walleyes, with as many a 20-30% being tumor-positive, congregate on shoals or in streams. Such crowding facilitates exposure of walleyes to walleye dermal sarcoma virus that may be free in the water. Initial efforts to investigate such a route of exposure consisted of preparing cell-free tumor filtrates and exposing fish via the topical route, oral route and intramuscular route. In all three cases, transmission was successful.

References:

Earnest-Koons, K., G.A. Wooster and P.R. Bowser. 1996. Invasive walleye dermal sarcoma in laboratory-maintained walleyes (Stizostedion vitreum). Diseases of Aquatic Organisms 24:227- 232.

Bowser, P.R., G.A. Wooster, and K. Earnest-Koons. 1997. Effects of fish age and challenge route in experimental transmission of walleye dermal sarcoma in walleyes by cell-free tumor filtrates. Journal of Aquatic Animal Health 9:274-278.

 


Epizootiology in Feral Fish in Oneida Lake
One of the questions arising from studies of seasonal incidence of walleye dermal sarcoma was whether a fish that was tumor-positive in a given year would again be tumor-positive in the following year. An investigation is underway to answer this question but the nature of the environment has required an indirect approach. The reason for this approach are as follows:

In any given spring, one can expect that approximately 20% of the adult walleyes brought to the Oneida Fish Hathery will be tumor-positive for WDS. In terms of numbers, this means that (approximately) 8,000 of the (approximately) 40,000 adult fish will be tumor positive. This is out of population of approximately 300,000 adult walleyes in Oneida Lake. If all 8,000 tumor-positive walleyes are tagged during the spring spawning run and are released into the lake, the chances of recapture of a tagged fish is 2.67% (8,000/300,000). The conclusion was that the direct approach of a mark and recapture study was not likely to be a productive effort.

The indirect approach consisted of a cooperative effort with the staff of the Cornell University Biological Field Station (CUBFS) on Oneida Lake. For several years, beginning in 1995, tumor prevalence data was collected as part of the walleye growth and life history studies of CUBFS. During the spawing run approximately 500 male and 500 female walleye were examined. Data collected included: sex, total length, age (scored from scales) and presence of walleye dermal sarcoma. The approach is to follow the various year classes of walleyes as they increase in age from each year to the next. If a walleye is tumor-positive in a given year and is again tumor-positive in the following year(s), one would expect tumor prevalence to be higher in older age classes. A preliminary examination of the data would suggest that this is not the case. An in-depth analysis of the data will be performed following collection of the 1999 data.

References:

Bowser, P.R., M.J. Wolfe, J.L. Forney, and G.A. Wooster. 1988. Seasonal prevalence of skin tumors from walleye (Stizostedion vitreum) from Oneida Lake, New York. J. Wildl. Dis. 24:292-298.

Getchell, R.G., J.W. Casey and P.R. Bowser. 1998. The seasonal occurrence of virally-induced skin tumors in wild fish. Journal of Aquatic Animal Health 10:191-201.

 


References

Walleye Dermal Sarcoma and Related References:

Bowser, P.R., M.J. Wolfe, J.L. Forney, and G.A. Wooster. 1988. Seasonal prevalence of skin tumors from walleye (Stizostedion vitreum) from Oneida Lake, New York. J. Wildl. Dis. 24:292-298.

Martineau, D., P.R. Bowser, G.A. Wooster and L.D. Armstrong. 1990. Experimental transmission of a dermal sarcoma in fingerling walleyes (Stizostedion vitreum vitreum). Vet. Pathol. 27:230-234.

Martineau, D., P.R. Bowser, G.A. Wooster, and J.L. Forney. 1990. Histologic and ultrastructural studies of dermal sarcoma of walleye (Pisces: Stizostedion vitreum). Vet. Pathol. 27:340- 346.

Bowser, P.R., D. Martineau, and G.A. Wooster. 1990. Effects of water temperature on experimental transmission of dermal sarcoma in fingerling walleyes (Stizostedion vitreum). J. Aquat. Animal Health 2:157-161.

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.

Bowser, P.R. and G.A. Wooster. 1991. Regression of dermal sarcoma in adult walleyes (Stizostedion vitreum). J. Aquat. Animal Health. 3:147-150.

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.

Bowser, P.R. and J.W. Casey. 1993. Retroviruses of fish. Ann. Rev. Fish Dis. 209-224.

Bowser, P. R. and G. A. Wooster. 1994. Ether sensitivity of the walleye dermal sarcoma virus. Journal of Aquatic Animal Health. 6:178-179.

Poulet, F.M., P.R. Bowser, and J.W. Casey. 1994. Retroviruses of fish, reptiles and molluscs. in: The Retroviruses, Volume 3. edited by J.A. Levy. Plenum Press, New York. pp. 1-37.

Poulet, F.M., V.M. Vogt, P.R. Bowser, and J.W. Casey. 1995. Insitu hybridization and immunohistochemical study of walleye dermal sarcoma (WDSV) nucleic acids and proteins in spontaneous sarcomas of adult walleye (Stizostedion vitreum). Veterinary Pathology. 32:162-172.

Poulet, F.M., P.R. Bowser, J.W. Casey. 1996. PCR and RT-PCR analysis of infection and trascriptional activity of walleye dermal sarcoma virus (WDSV) in organs of adult walleyes (Stizostedion vitreum). Veterinary Pathology. 33:66-73.

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.

Earnest-Koons, K., G.A. Wooster and P.R. Bowser. 1996. Invasive walleye dermal sarcoma in laboratory-maintained walleyes (Stizostedion vitreum). Diseases of Aquatic Organisms 24:227- 232.

Bowser, P.R., G.A. Wooster, S.L. Quackenbush, R.N. Casey and J.W. Casey. 1996. Comparison of fall and spring tumors as inocula for experimental transmission of walleye dermal sarcoma. Journal of Aquatic Animal Health. 7:78-81.

Bowser, P.R., G.A. Wooster, and K. Earnest-Koons. 1997. Effects of fish age and challenge route in experimental transmission of walleye dermal sarcoma in walleyes by cell-free tumor filtrates. Journal of Aquatic Animal Health 9:274-278.

Casey, R.N., S.L. Quackenbush, T.M. Work, G.H. Balazs, P.R. Bowser, and J.W. Casey. 1997. Evidence for retroviru infection in green sea turtles Chelonia mydas from the Hawaiian islands. Diseases of Aquatic Organisms. 31:1-7.

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.

Bowser, P.R., G.A. Wooster, K. Earnest-Koons, L.A. LaPierre, D.L. Holzschu and J.W. Casey. 1998. Experimental transmission of discrete epidermal hyperplasia in walleyes. Journal of Aquatic Animal Health. 10:282-286.

Holzschu, D.L., G.A. Wooster and P.R. Bowser. 1997. Experimental transmission of dermal sarcoma to the saugers Stizostedion canadense. Diseases of Aquatic Organisms. 32:9-14.

LaPierre, L.A., D.L. Holzschu, G.A. Wooster, P.R. Bowser, and J.W. Casey. 1998. Two closely related but distinct retroviruses are associated with walleye discrete epidermal hyperplasia. Journal of Virology. 72:3484-3490.

Getchell, R.G., J.W. Casey and P.R. Bowser. 1998. The seasonal occurrence of virally-induced skin tumors in wild fish. Journal of Aquatic Animal Health 10:191-201.

Quackenbush, S.L., T.M. Work, G.H. Balazs, R.N. Casey, J. Rovnak, A. Chavez, L. duToit, J.D. Baines, C.R. Parish, P.R. Bowser, and J.W. Casey. 1998. Three closely related herpesviruses are associated with fibropapillomatosis marine turtles. Virology 246:392-399.

Bowser, P.R., G.A. Wooster, and R.G. Getchell. 1998. Transmission of walleye dermal sarcoma and lymphocystis via water-borne exposure. Journal of Aquatic Animal Health. In press.

LaPierre, L.A., D.L. Holzschu, P.R. Bowser, and J.W. Casey. 1999. Sequence and transcriptional analyses of the fish retroviruses walleye epidermal hyperplasia virus types 1 and 2: evidence for gene duplication. Journal of Virology 73:9393-9403.

Bowser, P.R. and J.W. Casey. 2001. Genus Epsilonretrovirus (Retroviridae). pages 1020-1024 in The Springer Index of Viruses. C.A. Tidona and G. Darai (eds). Springer-Verlag. New York.

Getchell, R.G., G.A. Wooster, L.G. Rudstam, A.J. Van De Valk, T.E. Brooking, and P.R.Bowser. 2000. Prevalence of walleye dermal sarcoma by age class in walleyes (Stizostedion vitreum) from Oneida Lake, New York. Journal of Aquatic Animal Health. 12:220-223.

Getchell, R.G., G.A. Wooster, and P.R.Bowser. 2000. Temperature-associated regression of walleye dermal sarcoma tumors. Journal of Aquatic Animal Health. 12:189-195.

Quackenbush, S.L., J. Rovnak, R.N. Casey, T.A. Paul, P.R. Bowser, C. Sutton and J.W. Casey. 2001. Genetic relationship of tumor-associated piscine retroviruses. Marine Biotechnology 3:S88-S99.

Paul, T.A., J.C. Burns, H. Shike, R. Getchell, P.R. Bowser, K.E. Whitlock and J.W. Casey. 2001. Reporter gene expression in fish follows cutaneous infection with pantropic retroviral vectors. Marine Biotechnology 3:S81-S87.

Getchell, R.G., G.A. Wooster, and P.R.Bowser. 2001. Resistance to walleye dermal saracoma tumor redevelopment. Journal of Aquatic Animal Health. 13:228-233.

Bowser, P.R., G.A. Wooster, R.G. Getchell, T.A. Paul, R.N. Casey, and J.W. Casey. 2001. Experimental transmission of walleye dermal sarcoma in yellow perch, Perca flavescens. Journal of Aquatic Animal Health. 13:214-219.

Getchell, R.G., G.A. Wooster, C.A. Sutton, J.W. Casey, and P.R. Bowser. 2002. Dose titration of walleye dermal sarcoma tumor homogenate. Journal of Aquatic Animal Health. 14:247-253.

Bowser, P.R., G.A. Wooster, R.G. Getchell, C.-Y. Chen, C.A. Sutton, and J.W. Casey. 2002. Naturally occurring invasive walleye dermal sarcoma and attempted experimental transmission of the tumor. Journal of Aquatic Animal Health. 14:288-293.