A THERMAL-DENATURATION STUDY OF MACRONUCLEAR CHROMATIN IN BLEPHARISMA-JAPONICUM (PROTOZOA, CILIOPHORA, HETEROTRICHIDA)

The macronuclear chromatin of the ciliate Blepharisma japonicum, in tw o starvation states, was studied by thermal denaturation analysis. The behaviour of B. japonicum chromatin, native and reconstituted with Te trahymena pyriformis H1 histone, was analysed. The data obtained are c onsistent with the hypothesis that B. japonicum macronuclear chromatin contains a H1-like peptide associated with the linker DNA, although t his peptide is reduced in amount and/or chromatin stabilising ability when compared to Tetrahymena macronuclear H1.