Negative control of periodic tubulin gene expression in the mitotic cycle of Physarum polycephalum.
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.
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*
D012333:RNA, Messenger; D014404:Tubulin