Differential transcription of histone genes in asexual and sexual stages of Plasmodium falciparum

Molecular mechanisms of cell-cycle control in Plasmodium falciparum remain poorly understood. We have traced transcription of histones H2A, H2B and H3 as the parasite progresses through different developmental stages-rings, trophozoites, schizonts and gametocyles. Our results show that the ring stage parasites do not appear to synthesise any of the three histones. We also found a markedly elevated level of H3 transcript in the schizont stage parasite, while H2A and H2B were made in approximately equivalent amounts (in trophozoites, schizonts and garnetocytes). Further study might lead to a better understanding of the control elements involved in the regulation of histone levels in Plasmodium as it develops in the erythrocyte. (C) 1999 Australian Society for Parasitology Inc. Published by Elsevier Science Ltd. All rights reserved.