Genetic mapping of novel mutation, UV90, and its effects on the Neurospora crassa circadian system

Neurospora crassa is a model organism for circadian rhythm research. The FRQ-WCC feedback loop is the main mechanism driving rhythms in Neurospora. Recent evidence revealed a second oscillator in the absence of the FRQ-WCC loop, the FRQ-less oscillator (FLO). The purpose of this study was to identify the components and mechanism of the FLO. One mutation, UV90, disrupts the rhythmic conidiation of the FLO, and locating this gene will lead to better understanding of the FLO mechanism.

Mapping of the UV90 gene location was performed using Cleaved Amplified Polymorphic Sequence (CAPS) markers and gene knockout screens. DNA sequencing and complementation tests were performed to characterize the nature of the mutation and confirm the restoration of the UV90 phenotype.

Sequencing and complementation tests failed to reveal the exact nature of the mutation; however mapping and gene knockout studies confirmed the UV90 gene is represented by locus NCU05950 on Linkage Group VI.