Acquisition of expressed sequence tags from Schistosoma japonicum cercariae (mainland China strain) and its homology analysis.
OBJECTIVE: To understand the general profiles of the genes included in Schistosoma japonicum (Sj) cercarriae cDNA library that we have constructed for the purpose of identifying novel genes. METHODS: The phages in Sj cercariae cDNA library were transformed into plasmids after they had invaded into E.coli BM25.8, and the E.coli clones containing the plasmids were cultured in LB medium supplemented with aminobenzylpenicillin. The isolated colonies were selected for plasmid extraction and the DNAs subsequently extracted from the plasmids underwent sequence analysis with a sequencing primer to obtain the expressed sequence tags (ESTs). After sequence editing of the resulted ESTs, comparison of these sequences with those listed in the GenBank database was performed for homology analysis. The new sequences generated from the analysis were submitted to GenBank and the accession numbers acquired. RESULTS and CONCLUSION :Altogether 58 ESTs were identified among which 3 possed highly homologous nucleotide sequences with the known genes of Sj, 2 showed the homology with Schistosoma mansori genes, 7 had the homologous protein sequences, but not the nucleotide sequences, with other species, and another 27 were poorly homologous in terms of both the nucleotide and protein sequences.
Peng
Hong-Juan
HJ
Department of Parasitology, First Military Medical University, Guangzhou 510515, China.
Chen
Xiao-Guang
XG
Wang
Xun-Zhang
XZ