ABSTRACT. To characterize amino acid polymorphisms in sheep prion protein (PrP), we analyzed the PrP genes from 271 sheep of 4 breeds (Khalkh, Yeroo, Orkhon and Khangai) raised in central Mongolia (Tuv, Uvurkhangai and Selenge prefectures). A total of 16 genoty pes and 8 allelic variants of the PrP gene at codons 112, 136, 154 and 171 were found. At codon 171, 1.8% of the sheep had arginine/arginine (R/R) (resistant to scrapie) and 66.8% had glutamine/glutamine (Q/Q) (susceptible to scrapie). Several Yeroo and Orkhon sheep raised in Selenge prefecture had valine at codon 136 (136V) (highly susceptible to scrapie). Several Yeroo, Orkhon and Khangai sheep raised in Selenge prefecture had histidine at codon 154 (154H). Novel polymorphisms of valine (V) and serine (S) at codon 127, lysine (K) at codon 171, and leucine (L) and arginine (R) at codon 189 were also found in Khalkh, Yeroo and Orkhon sheep. It is not known whether these novel polymorphisms affect scrapie susceptibility.

We analyzed lactic acid bacteria (LAB) and yeast populations in samples of airag, undaa, and hoormog, which are varieties of traditional fermented milk produced in Mongolia. To effectively detect lactobacilli, lactococci/streptococci/enterococci, and leuconostocs for complete analysis of the complex LAB population in airag, we developed two new primer sets and examined these primer sets in three different combinations using denaturing gradient gel electrophoresis (DGGE). DGGE analysis revealed the diversity of the LAB and yeast populations in these traditional fermented milk samples; six to 11 LAB and yeast species were detected. The species common to all samples include Lactobacillus helveticus, Leuconostoc mesenteroides, Lactococcus lactis, and Kluyveromyces marxianus. Lc. raffinolactis, Enterococcus faecium/ hirae/durans/villorum/ratti, Streptococcus thermophilus, L. kefiranofaciens, L. kefiri/buchneri, Leu. citreum, and Leu. lactis were detected in multiple samples, while lactose non-fermenting Saccharomyces cerevisiae was only detected in one sample of hoormog.Keywords: traditional fermented milk, denaturing gradient gel electrophoresis, lactic acid bacteria, yeast *To whom correspondence should be addressed. E-mail: mari-miya@snowbrand.co.jp IntroductionAirag is the most popular traditional fermented milk in Mongolia. It is made using horse milk and has a low alcohol content (normally less than 3%). Similar types of traditional fermented milk are also consumed in Inner Mongolia (chigee and tsege) and Russia (koumiss). Hoormog and undaa, respectively prepared using the milk of camel and cow, are less popular types of Mongolian fermented milk.Airag is generally fermented by adding fresh raw milk to a small quantity of previously prepared airag, and the mixture is then stirred several thousand times. At the end of the horse lactation period, Mongolian people prepare hurunge, naturally dried airag which is stored for use as a starter culture in the following summer.

ABSTRACT. The use of Transgenic (Tg) mice expressing chimeric sheep/mouse (Sh/Mo) prion protein (PrP) and chimeric bovine/mouse (Bo/Mo) PrP genes was evaluated as a sheep scrapie model. We also investigated the potential for the transmission of sheep scrapie to a human/mouse (Hu/Mo) PrP Tg mouse line.