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Laboratory of Fish Immunology and Genetics

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Ramy R. Avtalion

Fish Immunology and Genetics








Research Interests and Achievements



Theoretical Research

          Effect of environmental temperature on the immune system of fish, with emphasis on regulatory effects of helper and suppressor functions. This model is currently used to study the mechanism of action of these functions, their kinetics, antagonism, cells subsets and production of specific and non-specific factor.

         Epitopic profile of cell surface antigens (lymphocytes and erythrocytes) of tilapia and goldfish with emphasis on cell subsets and MHC antigens, and development of appropriate monoclonal antibodies.

          Influence of stress on the immune system. By using fish (tilapia and striped bass) as animal model where stress can be easily induced and defined, the influence of stress on different functions of the immune system (e.g. antibody, phagocytosis, lymphocyte proliferation, natural killer cells) and on resistance to diseases are currently investigated.

          Transfer of specific immunity from mother to embryo in tilapias and goldfish: kinetics of maternally originated immunoglobulins and specific antibody activity in larvae; involvement in a viral tilapia encephalitis disease.

          Sex determination mechanism in tilapias and the crucial role of lethal genes in its regulation. This study is carried out with the BIU-O. aureus gynogenetic line using selected UNH-microsatelite markers.



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Applied Research

          Induced immunity and vaccination against agents of 2 important fish diseases: 1) goldfish ulcerative disease (GUD). An efficient vaccine is under development and will be available in the near future; 2) viral encephalitis of tilapia larvae.

          Chromosome set manipulations in tilapias for the creation of meiotic and mitotic clone. During last decade, our laboratory has investigated these subjects and different gynogenetic lines and clones were developed. Growth performance and sex ratios obtained in progenies of interspecific crosses (O. niloticus female X 0. aureus male) showed 100% of all male progenies with growth performances highest by 12% in comparison to normal strains. This genetic potential is the result of massive removal of defective genes and improvement of the genetic potential of the lines by full-sib matting along 5 gynogenetic generations.

          Creation of transgenic tilapias: The main objective of this study is to provide rapid genetic improvement of different traits such as growth rate and size, and low temperature resistance by using a technique of transfer of different genes (e.g. growth hormone gene, antifreeze gene, etc.).



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Last modified March 25, 2003



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