[Screening of stage-specific expression genes of Spirometra erinacei-europaei plerocercoid by mRNA differential display technique].
OBJECTIVE
To screen stage-specific expression genes of plerocercoid of Spirometra erinacei-europaei.


METHODS
RNA was extracted by the acid guanidinium thiocyanate-phenol-chloroform from plerocercoid and adult worm of Spirometra erinacei-europaei. Contaminated DNA in the RNA was digested by RNase-free DNase. cDNA was synthesized by using T12MA, T12MC, T12MG and T12MT primers, and PCR was then done using the same T12MN and one random primers. The PCR products were fractionated on 8% denatured polyacrylamide gel, differential bands of plerocercoid found in the gel were cut out, amplified by PCR and sequenced after the gel was dried out and autoradiographed. Northern hybridization was conducted to identify the stage-specific expression genes.


RESULTS
Eleven differential bands were selected from the gel and classified into 3 kinds of gene fragments by hybridization after they were amplified by PCR. The fragments 1 and 2 were confirmed to express specifically in plerocercoid by Northern hybridization, but the fragment 3 was expressed in both plerocercoid and adult worm. When the 3 gene fragments were homologically analyzed in GenBank, the sequence which was homologous with the fragments 1 and 2 was not found, but the fragment 3 had high homology with many kinds of 28S rRNA.


CONCLUSIONS
The gene expression of plerocercoid was different from that of adult worm probably because they live in different hosts. Two kinds of different gene fragments in plerocercoid were identified by mRNA differential display technique.
Liu
Dian-wu
DW
Department of Epidemiology, Hebei Medical University, Shijiazhuang 050017.
Zhu
Bing
B
Wang
Xiao-bo
XB
Yan
Hui-min
HM
Ding
Yue-xin
YX
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D020869:Gene Expression Profiling; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D016133:Polymerase Chain Reaction; D013146:Spirometra / Q000235:genetics*