Ribosomal and translatable messenger RNA of Eimeria tenella

RNA from oocysts of Eimeria tenella was purified into poly(A)--RNA and poly(A)+-RNA fractions with affinity chromatography on oligo(dT)-cellulose. Gel electrophoresis, under denaturing conditions of the poly(A)--RNA fraction revealed two major RNAs with molecular weights of 1.27 and 0.65 X 10(6). The values for these components not only represent the ribosomal RNAs of this species; but they also resemble the molecular sizes of the non-mRNAs of many other lower eukaryotes. In vitro translation assays with a cell-free wheat germ system showed that the level of translatable mRNA in the poly(A)--RNA fraction was negligible. Virtually all the translatable mRNA in E. tenella was polyadenylated, that is, it contained poly(A)-tracts with more than 15 adenylate residues. Consequently some of the key components of the protein translational machinery of this organism are eukaryotic in nature.