The perichromatin region: a functional compartment in the nucleus that determines large-scale chromatin folding.

The perichromatin region has emerged as an important functional domain of the interphase nucleus. Major nuclear functions, such as DNA replication and transcription, as well as different RNA processing factors, occur within this domain. In this review, we summarize in situ observations regarding chromatin structure analysed by transmission electron microscopy and compare results to data obtained by other methods. In particular, we address the functional architecture of the perichromatin region and the way chromatin may be folded within this nucleoplasmic domain.