title: Regulatory structures of gene expression, DNA-replication and DNA-rearrangement in macronuclear genes of Stylonychia lemnae, a hypotrichous ciliate.
abstract: Seven transcriptionally active macronuclear DNA molecules of Stylonychia lemnae have been analyzed for potential regulatory sequences of gene expression, DNA replication and DNA rearrangement. Transcription initiation is mediated by a canonical TATA-box or by TATA-box-like sequences, and transcription efficiency may be regulated by gene-specific downstream promoter elements (DPE). Putative signals for RNA 3'-formation are represented by noncon-served palindromes located upstream of the mature RNA 3'-termini. Sequences indicating polyadenylation of the mRNA molecules are not detectable. A single palindrome of A- and T-residues is present within the 80 5'-terminal bases of each macronuclear DNA molecule and very likely functions as the replication origin. The 7 DNA molecules consist of several nonconserved inverted and direct repeats (IR, DR) suggested to play a role in DNA rearrangement during macronuclear development.
authors.affiliation: Institut für Biologie III, Abt Zellbiologie, Universität Tübingen, Tübingen, FRG.
authors.forename: E
authors.initials: E
authors.lastname: Helftenbein
authors.forename: K K
authors.initials: KK
authors.lastname: Conzelmann
authors.forename: K F
authors.initials: KF
authors.lastname: Becker
authors.forename: H
authors.initials: H
authors.lastname: Fritzenschaf