Quasispecies groups in the core promoter region of hepatitis B virus.
OBJECTIVE
To investigate the mutation of the basic core promoter (BCP) of hepatitis B virus (HBV) and clarify the significance of HBV quasispecies groups in patients with chronic HBV infection.


METHODS
A set of specific primers was synthesized according to the HBV DNA sequence of a Chinese strain. The BCP was amplified by PCR method from the serum of 40 patients with chronic HBV infection, and the PCR products of 2 patients were subcloned into pGEM Teasy vectors. Polyacrylamide gel electrophoresis (PAGE) was employed to display the deletion mutations, and clones with differential length were selected to be sequenced. Sequence comparison was made to find the difference.


RESULTS
Two or three bands were displayed by PAGE in 60% patients. The results of sequence analysis showed that there are some kinds of mutations in the BCP region. The substitution always occurs in TATA-like boxes, especially from T to C on 140 site. The deletion mutations were detected in TA1, TA2 and TA3. The 8bp, 20bp deletion mutations frequently happened.


CONCLUSIONS
There is a hot deletion region in the BCP. The deletion and the substitution in the TATA-like box may influence the expression of preC/C protein. The sequencing results indicate that there are HBV quasispecies groups in patients with chronic HBV infection.
Deng
Hong
H
Department of Communicable Diseases, the Second Hospital of Xi'an Jiaotong University, Xi'an 710004, China. dhpd@pub.xaonline.com
Dong
Jing
J
Cheng
Jun
J
Huangfu
Kun-Jing
KJ
Shi
Shuang-Shuang
SS
Hong
Yuan
Y
Ren
Xi-Min
XM
Li
Li
L
D001483:Base Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D017353:Gene Deletion; D014644:Genetic Variation; D006512:Hepatitis B Core Antigens / Q000235:genetics*; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic
D006512:Hepatitis B Core Antigens