title: Negative control of periodic tubulin gene expression in the mitotic cycle of Physarum polycephalum.
abstract: Naturally synchronous syncytial plasmodia of Physarum polycephalum provide an ideal model for studying the eukaryotic cell cycle. The tubulin genes of Physarum provide a striking example of cell cycle-regulated gene expression: synthesis of both tubulin mRNA and the tubulin proteins is limited to the last three hours of G2 phase. Fusion of late G2-phase plasmodia, in which the tubulin genes are actively expressed, and mid-S phase plasmodia, in which the tubulin genes are not expressed, is used to demonstrate the presence of a diffusible negative regulator of tubulin gene expression in S-phase plasmodia. It is inferred that this factor is responsible for the turning-off of tubulin gene transcription that follows mitosis.
mesh_terms: D004261:DNA Replication; D005786:Gene Expression Regulation; D005796:Genes; D005800:Genes, Fungal; D007399:Interphase; D008938:Mitosis; D010804:Physarum / Q000235:genetics* / Q000254:growth & development; D012333:RNA, Messenger / Q000235:genetics; D014158:Transcription, Genetic; D014404:Tubulin / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D014404:Tubulin