Sun Xiuqin

Studies on immunodiagnosis of hepatopancreatic parvo-like virus disease of the Chinese penaeid,Penaeus Chinensis I. Purification of the virus

The viral discase of penaeids is indistinet but highly dangerous because their symptoms are often masked by some secondary ones.In order to gain knowledge on how to prevent the occurrence and spread of this viral disease, diagnostic studies on the early phase of the hepatopancreatic parvo-like viral (HPV) disease of culturedPenaeus chinensis was conducted using ummuno-serological techniques. The purification of HPV was successfully done by density gradient ultracentrifugation of cane sugar.

Isozyme expression of Chinese and Japanese populations ofChlamys farreri and their reciprocal hybrids

Chinese and Japanese population ofChlamys farreri and their reciprocal hybrids were surveyed in isozyme variability at 13 loci by polyacrytamide gel electrophoresis (PAGE). Isozyme banding patterns indicated these hybrids were diploid. Loci that were observed as being monomorphic in inbred populations ofC. farreri were also found to be monomorphic in filial progeny; loci that observed to be polymorphic in parental type generations were also polymorphic in hybrid generations. Differences existed among allelic frequency of the four types of cross. Within the reciprocal hybrids the expression of malic enzyme (ME) isozyme was sufficient to distinguishing individual hybrids because of the band, Rf=0.38. However, there were no noticeable variations among all the samples to differentiate one from another. Inbreeding was likely to be the main problem in aquaculture. The introduction of new broodstock can improve the genetic diversity. Hybrid vigor has manifested to a certain extent in the present study.

Electron microscope evidence of virus infection in cultured marine fish

Electron microscope investigation on the red sea bream (Pagrosomus major), bastard halibut (Paralichthys olivaceus) and stone flounder (Kareius bicoloratus) in North China revealed virus infection in the bodies of the dead and diseased fish. These viruses included the lymphocystis disease virus (LDV), parvovirus, globular virus, and a kind of baculavirus which was not discovered and reported before and is now tentatively named baculavirus of stone flounder (Kareius bicoloratus).

A study on pathogens of Chinese prawn (Penaeus Chinensis) virus diseases

This pathogenic study shows that the viral diseases of Chinese prawns (Penaeus chinensis, Osbeck) is due to three kinds of viruses: epithelium envelope baculovirus ofPenaeus chinensis (EEBV-PC, detected by the authors in 1993), infections hypodermal and hematopoietic necrosis virus, and hepatopancreatic parvo-like virus, and that the first two viruses seem to be the main pathogens of the epidemic in the northern regions in 1993.

Studies on immunodiagnosis of hepatopancreatic parvo-like virus diseases ofPenaeus orientalis

This paper describes a rapid procedure for diagnosis of penaeid viral disease using the immune serological method. The SPA (Staphylococcal Protein A) coagglutination test in early diagnosis of penaeid viral disease has yielded satisfactory results.This is the first time SPA is used in China for diagnoses of viral diseases of marine invertebrates, especially penaeid shrimp.The SPA early diagnostic method is characterized by accuracy, rapidity, simplicity and convenience, low cost, high specificity, strong sensitivity and micro-detectability, and easy dissemination and adaptability in prawn farms.

The phylogeny of yeasts—A cladistic analysis

Cladistic analysis was used to clarify the phylogeny of 16 genera of yeasts whose great morphological differences and inclusion in different classification systems resulted in controversies over the taxonomy of seven genera such asCrypeococcus. etc. Some scholars suggest that they belong to Ascomycetes, but others think they belong to fungi imperfecti. After comprehensive cladistic analysis of many genetic characters, the authors consider that the above-mentioned seven genera of yeasts developed in parallel with Ascomycetes so that they should belong to one and the same developmental system.