HISTONE SYNTHESIS IN TRYPANOSOMA-CRUZI

Trypanosoma cruzi is an ancient, parasitic eukaryote which does not un dergo chromatin condensation during cell division. This behavior may b e explained if one considers the strong amino acid sequence divergence of Trypanosoma histones compared to higher eukaryotes. In the latter organisms histone synthesis is coupled to DNA replication. Considering the nonconserved amino acid sequence of T. cruzi histones, as well as the absence of chromatin condensation in this organism, we have studi ed histone synthesis in relation to DNA replication in this parasite. We have found that core histones and a fraction of histone H1 are synt hesized concomitantly to DNA replication. However, another fraction of histone H1 is constitutively synthesized. (C) 1997 Academic Press.