Giardia lamblia is a widely concerned archezoan. In order to study the phylogeny of G.lamblia, ITS(1 and 2) of ribosome gene(rDNA) and 5.8 SrDNA from various Giardia strains were amplified,cloned and sequenced. A molecular phylogenetic tree was constructed with NJ method. After analyzed by DNAMAN software, 12 bases in 2 of the 10 squences were found to be substituted and 1 of the 2 had one base deletion, while the other 8 squences were quite homologous. The constructed phylogenetic tree was consistent with the phylogenic relationship reported previously. All the results show that ITS(1 and 2) and 5.8 SrRNA genes are effective genetic markers for studies of the evolution of Giardia.
To clarify the phylogenetic relationships and species status of Pneumocystis, the 5.8S rRNA gene and the internal transcribed spacers (ITS, 1 and 2) of Pneumocystis rRNA derived from rat, gerbil and human were amplified, cloned and sequenced. The genetic distance matrix of six Pneumocystis species compared with other fungi like Taphrina and Saccharomyces indicated that the Pneumocystis genus contained multiple species including Pneumocystis from gerbil. The phylogenetic tree also showed that Pneumocystis from human and monkey formed one group and four rodent Pneumocystis formed another group. Among the four members, Pneumocystis wakefieldiae was most closely related to Pneumocystis murina and Pneumocystis carinii, and was least related to gerbil Pneumocystis.
LI ZiHui1,2, FENG XianMin1, LU SiQi1, ZHANG Fan1, WANG FengYun1 & HUANG Song1 1 Department of Pathogenic Biology, Capital Medical University, Beijing 100069, China
