An unusual histone H3 specific for early macronuclear development in Euplotes crassus.

ABSTRACT: Characterization of the histone H3 genes of the ciliated protozoan Euplotes crassus indicates that one gene functions only during the sexual phase of the life cycle. Maximum expression of this gene, as judged by transcript accumulation, correlates with DNA replications leading to polytenization of the micronuclear chromosomes before massive DNA elimination, which produces a transcriptionally active macronucleus. Transcripts of the other gene accumulate primarily during vegetative growth and in the sexual phase of the life cycle during replication phases not related to polytenization. Although both histone H3 genes encode proteins that are fairly divergent in sequence at the amino terminus, the meiotic/polytene-specific histone H3 contains two insertions in the amino terminus that increase

SUBMITTER: Jahn CL 

PROVIDER: S-EPMC19791 | biostudies-literature | 1997 Feb

REPOSITORIES: biostudies-literature