Phage display antibody library has been proven to be a powerful technique used in development of antibodies. Since it was established in 1990, the technology has made enormous improvement and played more and more important role in basic research of biology, immunology, oncology, protein engineering, ligand-receptor studies and proteomics among others in last two decades while there is no report about the application of it in aquaculture so far. It is a success implication of phage display technique in antibody engineering in which antibodies or antibody fragments are displayed on the surface of filamentous bacteriophage by genetic fusion to a coat protein of phage. Cooperating with the effective screening technique, affinity panning, these form the principle of phage display antibody library. The most characteristic of it is a direct physical link between phenotype and genotype. So, the technology makes it practicable to improve characteristic of selected antibodies by genetic manipulation. In the present work, the background, principle and advantages of the powerful tool over traditional hybridroma technolgy are summarized. In addition, several key problems possible to face in the course of application of the technology, including improving the diversity of library, augmentation of library size, generation of high affinity antibody and effective screening of specific antibody were dissertated. At last the possible implication prospect of phage display antibody technique in aquaculture was discussed, especially in elucidating the immune system of fish and producing large amount antibodies with important diagnostic and therapeutic value in fish diseases.
Two new species of myxosporeans (Myxosporea:Bivalvulida),Mitrapora yiduensis sp.nov.and Myxobolus tuenfengensis sp.nov.,parasitic in freshwater fishes collected from the Yangtze River of China are described in this paper.All body organs of the host fishes,Siniperca chuatsi Basilewsky and Saurogobio dabrui Bleeker were examined and twenty spores of each myxosporean were measured with an eyepiece micrometer.All the measurement are in micrometers (μm) and the type specimens were deposited to Department of Fish Disease,the Institute of Hydrobiology, Chinese Academy of sciences,Wuhan,China. 1. Mitrapora yiduensis sp.nov. (Fig.1) Host:Sinperca chuatsi (Basilewsky) Location:Kidney Locality:Town of Yidu,Hubei province.(30°31′N,111°E) Date:May 1982. Vegetative form:Trophozites are amoeba-shaped about 20.6(18.5-23.2)by 18.4(16.5-20.6)in size. Spore:Bell-shaped in both thecal and sutural view.Blunt circular at anterior end and a truncate posterior end.Sutural ridge is straight.There are six lines on surface extending from the anterior end to the posterior end of the spore.Two pyriform polar capsules are equal in size and sporoplasm have an indinopilous vacuole and two round germinal nuclei.Dimension of spores preserved in 4%Formalin:Length 8.1 (7.2-8.4),width 5.2 (4.8-5.5),thickness 5.9 (5.8-6.2);length of the polar capsules 3.0 (2.8-3.2),width 2.1 (2.0-2.2). This species is similar to Mitraspora coreosiniperca Xiao at feng,1997,but the latter have a larger spore than the former and the former is blunt at anterior end of the spore,while the latter is slightly sharp at anterior end. 2. Myxobolus tuenfengensis sp.nov. (Fig.2) Host:Saurogobio dabryi Bleeker Location:Gill Locality:Tuanfeng Town,Hubei province(30°20′N,111°5′E) Date:June 1984. Cyst:Round or elliptical shaped with 0.3-0.5mm in size. Spore:Ovoid or nearly ellipsoid in thecal view and spindle in sutural view.The anterior end is truncate and the posterior end is blunt.The sutural ridge is rough and straight with distinct intercapsular appendix.Two pyriform
