The molecular genetic characterization of Aujeszky's disease virus (ADV) Yangsan strain (ADV-YS), a Korean isolate, was investigated by analyzing the electrophoresis patterns and the physical maps of the viral DNA digested with various endonucleases. To establish DNA library for ADV-YS, twelve major BamHI restricted segments were cloned. Each location of the segments in the ADV genome was determined by sequence comparison with the sequences reported in Genbank and those sequences of the both termini of the segments. Physical maps were constructed based on the electrophoresis patterns of the digested viral DNA by restriction endonuclease and the results of Southern blot analyses with various DIG labeled probes originated from those of enzyme restricted segments of virulent (Shope) and avirulent (Bartha) strain. Comparing ADV-YS with a standard strainof Kaplan in the maps of restriction enzymes, following major respects were identified: (ⅰ) disappearance of BamHI restriction site between the first and second BamHI segments, (ⅱ) creation of the BamHI restriction site in the fifth segment, and (ⅲ) generation of the BglⅡ site in the unique short (Us) regions. The genome of ADV-YS also contains a type 2 herpesvirus DNA molecule (in which the Us region only inverts itself relative to the unique longregion) like all other ADV strains except Norden strain(type3), analyzed up to date. The size of the ADV genome estimated from the sizes of the restriction enzyme fragments, was approximately 145.3kb (BamHI) or 145.3kb (BglⅡ) 145.4kb (BglⅡ). BamHI enzyme cleavage pattern were compared among the five Korean ADV isolates: Yangsan, Yongin, Dangjin, Jincheon and Iksan strains. Difference either in the number or in the size of the DNA fragments, suspected regions of termini of IR and TR, could be detected among all five strains.

For detecting Borna disease virus (BDV) genomic stranded RNA, single-tube reverse transcription-polymerase chain reaction (St RT-PCR) was developed to equal the sensitivity of RT-nested PCR but with reduced risk of contamination. BDV-genomic stranded RNA was synthesized in vitro using plasmid cDNA of BDV p24 region as a template and RNA was also extracted from BDV-persistently infected MDCK (MDCK/BDV) cells. Both RNAs were amplified by St RT-PCR in which a single round of RT and a single round of PCR were performed in the same tube. Ten copies of synthesized RNA could be amplified by St RT-PCR, indicating that St RT-PCR method is as sensitive as the ordinary RT-nested PCR method. Furthermore, this method was applied to quantify the exact copy number of genomic RNA in MDCK/BDV cells. Signals were obtained from the samples containing more than 1 pg total cellular RNA. From the results, approximately 100 copies of BDV genomic RNA exist in one MDCK/BDV cell. BDV genomic RNA from the in vivo RNA samples using St RT-PCR, indicating this method is applicable for the epidemiological study of BDV without contamination

Analysis of influence of boar genotype by MUC4 gene on viability of progeny was realized in the conditions in the Republic of Belarus, as well as the evaluation of possibilities of association of polymorphic variants of gene with fattening and meaty qualities of obtained from the boars progeny were conducted. In course of studies there was analyzed the polymorphism of MUC4 gene at producer boars of studied breeds. There was revealed high occurring frequency of desirable allele MUC4**c and MUC4**cc genotype in all studied populations. Boars of Belarusian Meaty breed with genotypes MUC4**cc by MUC4 gene authentically (P less than 0,01) exceeded boars with genotype MUC4**cg according to piglet viability indexes at weaning period on 5,6%. For the further evaluation of the potential role of MUC4gene in marker selection there was realized determination of relations between genotypes of studied marker and other economic traits of swine (fattening and meaty traits of boar progeny). There was stated the authentic increasing of fattening and meaty traits of stores obtained from boars with homozygous genotype MUC4**cc in comparison with progeny fathers of which in their genotype had mutant allel MUC4**g. For the forecasting and modeling of genotypes resistant to colibacillosis there was presented a scheme of selection boars and sows of different genotypes by MUC4 gene for the increasing of progeny viability. According to the scheme the preferred selection was MUC4**cc x MUC4**cc. This selection was recommended for the self-replacement and creation of nuclear stock