An apical complex of organelles for which the phylum Apicomplexa is named. They function during the attachment and entry of the parasite into the host cell. The apicoplast is thought to have arisen from an algal chloroplast by symbiogenesis (q.v.). The Plasmodium apicoplast contains a cir cular DNA molecule made up of 35 kbp in which are found genes that encode ribosomal RNAs, a complete set of tRNAs, ribosomal proteins, RNA polymerase subunits, and various proteases. Certain apicomplexans have secondarily lost their apicoplasts. See Classification, Protoctista; Cryptosporidium.
Subjects: Genetics and Genomics.