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This study was carried out to evaluate the features of neurological dysfunction in experimentally-induced bovine spongiform encephalopathy (BSE)-infected cattle using brainstem auditory evoked potentials (BAEP). The progressive prolongation of peak latency of waves III and V was observed right-and-left bilaterally at the onset of neurological symptoms. The peak latency of wave V and the I-V interpeak latency (IPL) in BSE cattle 22 and 24 months after intracerebral inoculation were significantly (P

application/pdf, Theileria orientalis is one of the benign species of Theileria that is widely distributed in Japan and is sometimes responsible for serious economic losses in the livestock industry. In the present study, we surveyed the current status of T. orientalis infection in grazing cattle in the eastern areas of Hokkaido (Taiki, Otofuke, Shintoku, and Shin-Hidaka districts) using molecular methods, as well as traditional methods, of diagnosis. The genes encoding the major piroplasm surface protein (MPSP) and p23 of T. orientalis were identified using highly detectable polymerase chain reaction (PCR). Results of the MPSP-PCR assay indicated that grazing cattle in these districts, after about 1.5 months pasturage, showed high rates of infection, ranging from 10.0-64.8%. Although the main MPSP and p23 genotypes detected were the Ikeda-or Chitose-types, an MPSP gene closely relating to that found in Okinawa prefecture, and a p23 gene closely relating to the Australian (Warwick) Buffeli-type gene, were found in the cattle in Shintoku and Shin-Hidaka districts. The present survey indicated that there were at least five types of T. orientalis classified by their MPSP genes in Hokkaido, Japan, and that T. orientalis infection rates are still high in this region.

Loop-mediated isothermal amplification (LAMP) is a novel DNA amplification method that amplifies a target sequence specifically under isothermal conditions. The product of LAMP is detected by the turbidity of the reaction mixture without electrophoresis. The objective of this study was to develop a rapid sexing method for bovine preimplantation embryos using LAMP. The first experiment was conducted to optimize the DNA extraction method for LAMP-based embryo sexing. The DNA of single blastomeres was extracted using three methods: heat, NaOH, and proteinase K-Tween 20 (PK-TW) treatments. Sexing was performed with two LAMP reactions, male-specific and male-female common reaction, after DNA extraction. The rates of correct determination of sex were 88.9-94.4%, with no difference among methods. The sensitivity and accuracy of LAMP-based embryo sexing were evaluated in the next experiment. The proportion of samples in which the sex was correctly determined was 75-100% for one to five biopsied cells. Lastly, in vivo-derived embryos were examined to verify the usefulness of LAMP-based embryo sexing, and some of these fresh, sexed embryos were transferred into recipient animals. The time needed for sexing was