Morphometrical analysis of chicken Crytosporidium baileyi in various stages of life cycle in the bursa of Fabricius wer carried out by electron microscope to establish a differential point for identification of C baileyi. By avidin-biotin complex method, protozoans of the bursa of Favricius were identified Cryptosporidium spp. The size and area on each developmental stages of C baileyi, as measured by Morphomat 10 attached to electron microscope were as follews. Trophozoites' size with range of 3.21+_0.70*2.49+_0.59 micro meter, area with range of 118. 82+_41.92 micro meter2; meronts' size with 3.99+_1.07*2.96+_0.52 micro meter, area 210.11+_57.11 micro meter2 ; merozoites' size 1.98+_0.43*0.60+_0.18 micro meter, area 24.10+_5.97 micro meter2; microgametes' size 1.36+_0.83*0.50+_0.23 micro meter, area 20.23+_6.73 micro meter2; macrogametes'size 4.57+_0.65*4.02+_0.55 micro meter, area 258.37+_51.83 micro meter2; oocytes' size 4.39+_0.56*3.44+_0.50 micro meter, area 187.21 +_62.68 micro meter2. In conclusion, the size and area on each developmental stages of Cryptosporidium baileyi is different from that of other Cryptosporidia spp. It suggests, with considering tissue tropism and life cycle, morphometrical analysis can be quite a good way to identify C baileyi.

Ixodes persulcatus Schulze (I. persulcatus) is distributed in Russia and Far East Asia including Japan, and has been implicated as the vector of several human pathogens. In particular, I. persulcatus acts as the only tick vector for human lyme borreliosis in Japan. In order to elucidate the mechanism of transmission of I. persulcatus-borne pathogens, we developed a laboratory colony of I. persulcatus. Ticks were fed on Syrian hamster and engorged ticks that had dropped off the animals were collected and maintained to allow them to molt. Tick rearing was performed in incubator at 20degC with 95% relative humidity and 12-hour light/dark photo-period regimen. We found out that adult females fed for 8+-2 days and had a pre-oviposition period lasting for 7+-2 days. The minimum egg incubation period was 1 month with the hatched larvae feeding for 3+-1 days and molting to nymphs 3-4 months thereafter. Meanwhile, the nymphs fed for 4+-1 days and molted to adult 2-3 months thereafter. For future analysis of gene expression profiles in I. persulcatus, we cloned and sequenced the actin gene (a housekeeping gene), and found that it is 92.7% to 98.6% homologous to the published sequences of related ixodid ticks. This laboratory colony of I. persulcatus will facilitate investigations on the role of tick-derived molecules on the transmission of I. persulcatus-borne pathogens and will be important for identification of potential anti-tick vaccine and acaricide target molecules.