Plastid in human parasites

摘要

SIR — The discovery in malarial and toxoplasmodial parasites of genes normally occurring in the photosynthetic organelle of plants and algae has prompted speculation that these protozoans might harbour a vestigial plastid. The plastid-like parasite genes occur on an extrachromosomal, maternally inherited, 35-kilobase DNA circle with an architecture reminiscent of that of plastid genomes. Although the 35-kb genome is distinct from the 6-7-kb linear mitochondrial genome, it is, not known where in theparasite cells the plastid-like genome resides.