Biological Parameters of Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) Fed on Rabbits, Sheep, and Cattle

In order to determine the effect of various hosts on feeding performance of Rhipicephalus (Boophilus) microplus, we used 3 mammalian species as hosts, cattle (Qinchuan), sheep (T an), and rabbits (Japanese white rabbit) for infest-ing ticks. Five hundreds of R. microplus larvae were exposed to each animal (3 animals/host species). Tick recoveries were 11.0%, 0.47%, and 5.5% from cattle, sheep, and rabbits, respectively. The averages of tick feeding periods were not significantly different on cattle, sheep, and rabbits, 28.8, 25.3, and 26.7 days, respectively. The average weights of individual engorged female from cattle, sheep, and rabbits were 312.5, 219.1, and 130.2 mg, respectively and those of egg mass weights each to 85.0, 96.6, and 17.8 mg. The highest egg hatching rate was in the ticks from cattle (96.0%), fol-lowed by those from rabbits (83.0%) and sheep (19.2%). These data suggest that rabbits could be as an alternative host to cultivate R. microplus for evaluating vaccines and chemical and biological medicines against the tick in the laboratory, although the biological parameters of ticks were less than those from cattle.

Phylogenetic Analysis of Ruminant Theileria spp. from China Based on 28S Ribosomal RNA Gene

Species identification using DNA sequences is the basis for DNA taxonomy. In this study, we sequenced the ribosomal large-subunit RNA gene sequences (3,037-3,061 bp) in length of 13 Chinese Theileria stocks that were infective to cattle and sheep. The complete 28S rRNA gene is relatively difficult to amplify and its conserved region is not important for phylogenetic study. Therefore, we selected the D2-D3 region from the complete 28S rRNA sequences for phylogenetic analysis. Our analyses of 28S rRNA gene sequences showed that the 28S rRNA was useful as a phylogenetic marker for analyzing the relationships among Theileria spp. in ruminants. In addition, the D2-D3 region was a short segment that could be used instead of the whole 28S rRNA sequence during the phylogenetic analysis of Theileria, and it may be an ideal DNA barcode.

Prokaryotic Expression of Bm86 Gene of Boophilus microplus and Optimization of the Expression Condition / 中国寄生虫学与寄生虫病杂志

A pair of specific primers was designed based on the reported Bm86 gene of Boophilus microplus,the Bm86 gene was cloned by PCR using the plasmid pMD18-T-Bm86 as templates,and subcloned into the prokaryotic plasmid pGEX-4T-1.The recombined plasmid was transformed into E.coli BL21(DE3) and followed by expression of the protein induced by different concentration of IPTG for different time.SDS-PAGE showed that the recombinant plasmid pGEX-4T-1/Bm86 expressed a fusion protein Bm86-GST(Mr 94 000) after being induced with IPTG.High level expre-ssion of Bm86-GST was found at 1 mmol/L IPTG condition after incubation for 8 h at 37 ℃,and the expression level of the recom-binant Bm86-GST reached up to 29% of total E.coli proteins.Western-blotting analysis showed that the recombinant Bm86-GST was recognized by the rabbit anti-B.microplus positive serum.