Circadian clocks are present in most eukaryotes and some prokaryotes and control
rhythms in behavior, physiology and gene expression. One well-characterized circadian
clock is that of Neurospora crassa. In addition to the well-described N. crassa
FRQ/WCC oscillator, several lines of evidence have implied the presence of other
oscillators which may have important functions in the N. crassa circadian clock system.
However, the molecular details are only known for the core FRQ/WCC oscillator. The
light mutant oscillator (LMO) was identified by two mutations (LM-1 and LM-2) and
shown to control developmental rhythms in constant light (LL), conditions in which the
FRQ/WCC oscillator is not functional. The objective of this project was to determine
whether the developmental rhythms driven by the LMO are circadian, whether the
components of the LMO communicate with components of the FRQ/WCC oscillator,
and to begin to define the molecular nature of the LMO.
First, the conditions for growth of the LM-1 mutant strain that reveals the best circadian
rhythm of development in LL were found. Second, the LMO was determined to display the three properties required of a circadian oscillator. Third, the LMO was shown to
function independently of the FRQ/WCC oscillator to control developmental rhythms in
LL. However, evidence suggests that the FRQ/WCC oscillator and the LMO
communicate with each other. Finally, using Cleaved Amplified Polymorphic Sequence
(CAPS) markers, the LM-1 mutation was genetically mapped to the right arm of linkage
group I within a 1069 kb region. Together, these results provide a start towards
understanding of the complexity of oscillators that form a circadian clock in organisms.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2885 |
| Date | 15 May 2009 |
| Creators | Huang, He |
| Contributors | Bell-Pedersen, Deborah |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | electronic, application/pdf, born digital |
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