Postdoctoral Reserch Fellowships in Microbial Biology

Ditty, Jayna L, College Station TX

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Microbial Biology for 2000. The research and training plan is in the area of Microbial Genetics and is entitled "Characterization of a Second Circadian Oscillator in Synechococcus sp. Strain PCC 7942". The single-celled cyanobacterium, Synechococcus sp. Strain PCC 7942 has a circadian pacemaker or "clock" consisting of at least three genes (kaiA, kaiB, and kaiC) that has an endogenous period of 25 hours. A second, mutant clock with a 27.5-hour period has been shown in the sigC mutant of Synechococcus. While experiments have shown kaiA in this mutant to oscillate with the 27.5 hour period, kaiB exhibits the wild-type 25 hour periodicity, leading to the hypothesis that there is an unforeseen oscillator (UFO) present that is overruled under wild-type (i.e. normal) conditions by the master Kai oscillator. This research physiologically characterizes the 27.5-hour oscillation of strain PCC 7942 by examining its temperature compensation and ability to phase reset. In addition, the molecular basis of the 27.5-hour UFO and its effects on synechococcal circadian gene expression is investigated.