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Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of South China Fisheries Science is the property of South China Fisheries Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

By using cell culture and virus infection methods, a new reovirus had been isolated from channel catfish (Ictalurus punctatus) suffered with severe hemorrhage and had been identified as channel catfish reovirus (CCRV) after artificial infection in fish, electron microscopy observation, physical-chemical tests, genomic SDS-PAGE analysis and sequencing. In artificial infection test, the typical symptoms of channel catfish hemorrhage as naturally occurred could be reproduced. The isolated virus could cause typical cytopathic effect in CCO and CCK cell lines. Electron microscopy observation of ultra-thin section samples of CCRV infected CCO and CCK cells revealed that the virus replicated in cytoplasm, arrayed in crystalline, and had a non-enveloped double capsid with a diameter of 60-70 nm. Frozen-thawed, 56 degrees C 1 h, chloroform and ether had no significant effects on CCRV titer, 65 degrees C 1 h could significantly inactivated the viral infectivity. The CCRV genome SDS-PAGE analysis and nuclease sensitivity test showed that the virus genome was the same as that of viruses in Aquareovirudae and consisted of 11 segments of dsRNA assigned into three classes L1, L2, L3; M1, M2, M3 and S1, S2, S3, S4, S5 with a range of size from 0.9 to 4.4 kb. The Cloning and sequencing of the CCRV S4 segment indicated the nucleic acid number of CCRV S4 was 909 bp in length, which was exactly the same as that of GCRV S4 (AF403396) and GSRV S4 (AF403407) segments. The BLAST of CCRV S4 sequence in NCBI GenBank showed that it had a 99% and 90% similarity in sequence to the GCRV S4 and GSRV S4 segments, respectively.

Total RNA was isolated from pituitary gland of Clarias lazera, and the cDNA encoding growth hormone (GH) protein was amplified and cloned by reverse transcription polymerase chain reaction (RT-PCR). The open reading frame (ORF) of cDNA is of 603 nt which encodes GH precursor consisted of a signal peptide with 22 amino acid residues and a mature peptide with 178 amino acid residues. Sequence alignment indicated that the amino acid sequence homology approached to 95.8% between C. lazera and other 6 species of Siluriforms catfish. Secondary structure assessment showed that the GH protein contained different structural regions of alpha-helix, beta-sheet, beta-turn and random coil, among which alpha-helix has main proportion. Antigenicity analysis indicates that there exist 4 domains in amino acid sequence where B cell dominant epitopes could form. Summarily, the structure characteristics of C. lazera GH should provide a great benefit in its modification into recombinant vaccine or monoclonal antibody for future application.

The type and distribution of mucous cells stained with AB & PAS (pHAB=2.6) in the intestine tract of silurus asotus (body length 16.4-21.0cm, body weight 33.6-64.3g) have been studied. The development and secreting activity of mucous cells have been investigated using scanning and transmission electron microscopy. The results showed that the mucous cells were dark blue,weak blue and cambridge blue in colour after being stained with AB & PAS(pHAB=2.6); it mainly contained acid mucopolysaccharides; the mucous cells had 3 shapes i.e. capsule-shaped, pear-shaped and cup-shaped. The capsule-shaped mucous cells were distributed in the bottom of the epithelia of the intestine, and its diameter was about 4.40 microm. The pear-shaped mucous cells were distributed in the middle-layer of the epithelia of the intestine, and its vertical range and sidelong was about 6.00 microm and 3.40 microm respectively. The cup-shaped mucous cells were distributed in the top of the epithelia of the intestine, and its vertical range and sidelong was about 12.00 microm and 4.60 microm respectively. The density of mucous cells presented an increasing trend from the anterior(low) to posterior(high) and middle(higher) segment. After derived from bottom cells, the mucous cells evolved gradually from fundus film to exterior of mucous membrane. The mucous cells in developing were filled with plenty of big and small mucosity particulates, and the secreting method of mucous cells was peak serosity secretion.