[Molecular phylogeny of Giardia lamblia based on triose phosphate isomerase (tim) gene sequence].
OBJECTIVE
To investigate the intraspecies phylogeny and genetic diversity of G. lamblia.


METHODS
Total genomic DNA was extracted and partial fragments of tim gene were amplified by PCR. All the nucleotide sequences were analyzed by means of phylogenetic analysis, which were constructed with pasimony and N-J methods.


RESULTS
A total of 124 variable sites (23% of the total sequences detected) were defined, most of which were found at the silent sites of codons. Two similar phylogenetic trees were constructed, subdividing 16 isolates into two groups.


CONCLUSIONS
The genetic diversity of G. lamblia appear to be little affected by both the host and geography, while natural-selection might play an important role at the DNA molecular evolution level of tim gene. The tim gene may be considered to be a very useful genetic marker of the population genetic structure of G. lamblia.
Li
J H
JH
Key Laboratory of Cellular and Molecular Evolution, Chinese Academy of Sciences, Kunming 650233.
Lu
S Q
SQ
Zhang
Y P
YP
Wang
F Y
FY
Wen
J F
JF
D000818:Animals; D001483:Base Sequence; D016054:DNA, Protozoan / Q000235:genetics; D014644:Genetic Variation; D016829:Giardia lamblia / Q000201:enzymology / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014305:Triose-Phosphate Isomerase / Q000235:genetics*
D016054:DNA, Protozoan; D014305:Triose-Phosphate Isomerase