随着全球经济一体化进程的加速，国际贸易和国际交往日趋频繁，动物海绵状脑病在全球扩散的危险性大大增加，疯牛病（BSE）、羊痒病（Scrapie）等在世界范围内呈蔓延的趋势。现在除欧洲外，其它各洲也有报道，BSE、羊痒病等动物海绵状脑病在我国周边国家也呈流行趋势，严重威胁着我国的畜牧业生产。我国虽然至今尚未发现BSE，但因我国幅员辽阔，传入的可能性较高，因此，我们必须提高警惕，建立严密的BSE监测系统，采取主动检测和报告制度。我国政府高度重视对BSE、羊痒病等疫病的检测和监测工作，本实验室于2001年被认定为国家动物海绵状脑病检测实验室，负责检测、监测黑龙江省、内蒙古自治区、辽宁省、吉林省和北京市五省市的BSE检测工作，现将结果报告如下。

A Yunnan pony ear marginal tissue fibroblast cell line (NYPEM 2/2) was successfully established using the ex2 plant of the ear marginal tissue and then trypsinization the cells from the outgrowth. Observations on cell morphology and dynamic growth, analysis of karyotype and isoenzymes of lactate dehydrogenase and malate dehydrogenase were carried out. The expression of recombinant green fluorescence protein in the cells were also undertaken. The results showed that the population doubling time (PDT) of the cells was 24h; the frequency of cell chromosome number to be 2n=64 was 9219%; the banding patterns of the isozymes of the two enzymes had significant difference between the Yunnan pony ear marginal fibroblast cell line and the fibroblast cell lines of PEM 2/2, MSHEM 2/2 and BLCHE 2/2 derived from the Picdmont bovine ear, Mongolian ovine ear and Beijing local chicken embryo respectively. Tests for the contamination from bacteria, fungi or mycoplasma were negative; the transfection efficiency for the recombinant plasmid was 3213%. This newly established cell line make the Yunnan pony breed, a national important genetic resource preserved at cell level, as well as will provide an effective experimental material for genetic studies on the Yunnan pony

Prion diseases (transmissible spongiform encephalopathies, TSE), as a group of fatal neurodegenerative diseases, have affected humans and a variety of other mammals. Although no natural TSE have been documented in pigs, appropriate precautions need to be taken to prevent the iatrogenic spread of prion disease through pig-to-human xenotransplantation. Polymorphisms within the open reading frame (ORF) of the single-copy gene of prion protein (PRNP) are associated with susceptibility to scrapie in sheep and variant Creutzfeldt-Jacob disease in humans. We screened polymorphisms in the PRNP gene of 64 China Experimental Minipigs and Beijing Large White pigs. Our findings suggest that the porcine PRNP gene is highly homogenous. The amino acid sequences of the mature prion protein of all samples tested were identical. Four single nucleotide polymorphisms (G11A, G615C, G684A, T726G) in the ORF of the porcine PRNP gene were found, and the G fi C nucleotide substitution resulted in a serine to asparaginate amino acid substitution at codon 4. We conclude that pigs raised under specific pathogen-free conditions, with the exclusion of rendered mammalian material for at least two generations, will have little risk of being infected with a TSE, and even less possibility of transmitting prion disease to humans through xenotransplantation.

Determination of tissue-specific expression of cellular prion protein (prpc) is essential for understanding its poorly explained role in organisms. Herein we report on quantification of prp Mrna in golden hamsters,a popular experimental model for studying mechanisms of transmissible spongiform encephalopahies (TSE), by real-time RT-PCR.Total RNA was isolated from four different regions of the brain and six peripheral organs of eight golden hamsters Prp Mrna copy number were determined using absolute standard curve method with real-time quantitative PCR instrument.I was found that high Mrna levels were present in all four regions of the brain examined,ingunal lymph node showed high level of the expression similar to that in overall brain; spleen, heart, liver, and lung showed moder-ate levels of the expression; and kidney showed the lowest expression. Our result is consist-ent with the potential involveoment of different organs in prion diseases and offers essentialdata for further study of TSE mechanism in this animalmodel.