关键词: 疟疾, 三日疟原虫, 表面抗原基因

Abstract: The genomic Hind Ⅲ λgt1149 library from Plasmodium malariae was screened with two types of oligonucleotides, both of which were from the P190 gene of P. falciparum. One, MAD20 type, was made from spanning nwcleotides 4488-4562 in the P100 gene of MAD20 strain and another, K1 type, was made from spanning nucleotides 3652-3692 in the P190 of K1 strain. Both were end-labelled with 32P-ATP as probes before hybridization. Two clones were selected. One clone, designated XMSA-1, was specifically recognized by the MAD20 type oligo probe; the other,designated XMSA-2,by the K1 type oligo probe. XMSA-1 and AMSA-2 inserts were obtained by Hind Ⅲ digestion of the two-clone phage DNA. The analysis of the two inserts showed that the size of X.MSA-1 is 5.5 kb whilst that of XMSA-2 is 3.5kb. The MSA-1 and MSA-2 inserts recloned into PUC8 were digested with the restriction enzymes Bg1 Ⅱ, EcoR Ⅰ , Xba Ⅰ , Hind Ⅱ and Pst Ⅰ. The results showed that the MSA-1 DNA had one Bgl Ⅱ site, one EcoR Ⅰsite, two Xba Ⅰ sites, one Hind Ⅱ site and one Pst Ⅰ site. The MSA-2 DNA had only one Hindn site.The surface antigen gene of P. malariae was little known. This result also showed that there was probably an analogue of P190 on the surface of P. malariae, and they might fall into two types. This study is informative for further investigation on malariae parasites (Figs. 1-8).