Tandemly arranged gene clusters of malarial parasites that are highly conserved and transcribed

A molecular clone containing a 5.8 kb Eco RI fragment was isolated from a genomic library of the rodent malarial parasite Plasmodium yoelii. The P. yoelii genome contains about 150 copies of this sequence, making up almost 3% of the DNA. These sequences are tandemly arrayed in head-to-tail configurations with the unit length of the repeat being 5.8 kb. Several poly(A +) RNAs of P. yoelii ranging from 1.6 to 0.3 kb are recognized by the 5.8 kb clone. Five additional species of malarial parasites ( P. chabaudi, P. berghei, P. falciparum, P. knowlesi, and P. cynomolgi) contain tandemly repeated arrays of sequences having the same unit length of 5.8 kb, which readily hybridize to the sequence cloned from P. yoelii.