碩士 / 國立屏東科技大學 / 獸醫學系 / 92 / Cobia Rachycentron canadum (Linnaeus) culture offers great possibilities in aquaculture, because of its fast growth rate and its commercial interest. Recently farmers are facing problems in cobia culture due to disease outbreak and cause mass mortalities in cage cultured juvenile cobia, especially cobia photobacteriosis (junior synonym pseudotuberculosis or pasteurellosis). The photobacteriosis pathogen is Photobacterium damselae subsp. piscicida, have 50 to 60﹪mortalities in cobia. This study presents basic data on the growth of the lymphoid organs (include head kidney, spleen and thymus) in cobia, from 1 to 8 months. The growth and cellular composition of the kidney, spleen and thymus were detected in cobia. The age showed a higher imperfect correlation to body fork than body weight (γ=0.9961 and γ=0.9073). All lymphoid organ weight showed a higher imperfect correlation to body weight than they did to age and body fork (γ=0.9995, γ=0.9993 and γ=0.9968). In the other hand, all organs grew as the fish grew, but they attainted their maximum relative weights (expressed as a percentage of body weight) at 2-3 months of age. The total number of leucocytes in the lymphoid organ tissue, and per gram of tissue per gram of fish, decreased with age. The blood picture showed no obvious fluctuations with age. Lysozyme activity of all lymphoid organ and serum from 3-8 months of age, results showed no significant different (p＞0.05). Lipopolysaccharides (LPS, endotoxin) are associated with the cell walls of Gram-negative bacteria, often play a important virulence factor in bacterial pathogenicity. So, studies on molecular cloning of the LPS biosynthesis regulator protein gene of P. damselae subsp. piscicida by using E. coli expression system and pRSET vector, expect it could be potential used as a candidate antigen for development of subunit vaccine against P. damselae subsp. piscicida in the near future. The purified expressed recombinant fusion protein was abtained by using 6×His affinity column and was strongly reactive to rabbit-P. damselae subsp. piscicida ECP-antibody by using Western blotting assay in terms of antigenicity.
| Identifer | oai:union.ndltd.org:TW/092NPUST541013 |
| Date | January 2004 |
| Creators | Shu-Yun Cheng, 鄭淑云 |
| Contributors | Shih-Chu Chen, 陳石柱 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 96 |
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