Ref ID : 508
C.M.S. Dass, G.R. Sapra, and Rajesh Kumar; Fine structure and nucleic acid synthesis during macronuclear development in Blepharisma musculus var. seshachari. Arch.Protistenk 126:293-308, 1982
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During the course of macronuclear development in Blepharisma musculus, there is an uninterrupted synthesis and accumulation of DNA until the end of development. Ultrastructurally, these changes are manifested as progressive increase in the packing, density and condensation of the chromatin fibres. Chromatin condensation starts at several small "condensation centers" which gradually enlarge and ultimately fuse with each other so as to form a dense reticulum. At no stage during development, there is any detectable depletion of DNA from the macronuclear anlage. A conspicuous but short-lived phenomenon is the formation of pre-nucleolar bodies, which appear in the macronuclear anlagen soon after differentiation. Shortly afterwards, several typical but small-sized nucleoli are formed. This event closely coincides with the onset of RNA synthesis by the new macronucleus. Old macronuclear fragments also remain transcriptionally active until they are totally resorbed.