A5012555968- Seismic Waves and Analysis
- Methane Hydrates and Related Phenomena
- Earthquake Detection and Analysis
- Ionosphere and magnetosphere dynamics
- Circadian rhythm and melatonin
- Light effects on plants
- Photoreceptor and optogenetics research
- Photosynthetic Processes and Mechanisms
- Plant Molecular Biology Research
- Plant and Biological Electrophysiology Studies
- Fungal and yeast genetics research
- Genetics, Aging, and Longevity in Model Organisms
- Algal biology and biofuel production
- bioluminescence and chemiluminescence research
- Geophysics and Gravity Measurements
- Protist diversity and phylogeny
- Astrophysics and Cosmic Phenomena
- Seismology and Earthquake Studies
- Spaceflight effects on biology
- Microbial Metabolic Engineering and Bioproduction
- Plant-Microbe Interactions and Immunity
- Plant Reproductive Biology
- Mycorrhizal Fungi and Plant Interactions
- Fungal Biology and Applications
- Gene Regulatory Network Analysis
Dartmouth Hospital
1990-2024
Dartmouth College
2015-2024
Cornell University
2007-2024
SUNY Upstate Medical University
2023-2024
ScienceSouth
2021-2022
EarthTech International (United States)
2013
Texas A&M University
2013
Dartmouth–Hitchcock Medical Center
2011
Laboratoire de Biologie Moléculaire des Eucaryotes
2009
University of Stavanger
2005
Neurospora crassa is a central organism in the history of twentieth-century genetics, biochemistry and molecular biology. Here, we report high-quality draft sequence N. genome. The approximately 40-megabase genome encodes about 10,000 protein-coding genes--more than twice as many fission yeast Schizosaccharomyces pombe only 25% fewer fruitfly Drosophila melanogaster. Analysis gene set yields insights into unexpected aspects biology including identification genes potentially associated with...
The low rate of homologous recombination exhibited by wild-type strains filamentous fungi has hindered development high-throughput gene knockout procedures for this group organisms. In study, we describe a method rapidly creating mutants in which make use yeast recombinational cloning, Neurospora mutant deficient nonhomologous end-joining DNA repair, custom-written software tools, and robotics. To illustrate our approach, have created bearing deletions 103 genes encoding transcription...
To understand how light might entrain a mammalian circadian clock, we examined the effects of on mPer1, sequence homolog Drosophila per, that exhibits robust rhythmic expression in SCN. mPer1 is rapidly induced by short duration exposure to at levels sufficient reset and dose–response curves reveal induction shows both reciprocity strong correlation with phase shifting overt rhythm. Thus, phasing dark response most similar Neurospora clock gene frq. Within SCN there appears be localization...
1. Overview of Biological Timing from Unicells to Humans 2. The Behavioral Ecology and Evolution Systems 3. Fundamental Properties Circadian Rhythms 4. Circannual Photoperiodism 5. Functional Organization in Multicellular Animals 6. Cell Physiology In Metazoan 7. Molecular Biology Pacemaker 8. Adapting Life on a Rotating World at the Gene Expression Level 9. Human 10. Relevance for Welfare 11. Looking Forward Glossary Species List
The frequency ( frq ) locus of Neurospora crassa was originally identified in searches for loci encoding components the circadian clock. gene is now shown to encode a central component molecular feedback loop which product negatively regulated its own transcript, resulted daily oscillation amount transcript. Rhythmic messenger RNA expression essential overt rhythmicity organism and no constitutive rescued normal loss-of-function mutants. Step reductions FRQ-encoding transcript set clock...
In the fungus Neurospora crassa , blue light photoreceptor(s) and signaling pathway(s) have not been identified. We examined by exploiting sensitivity of biological clock, specifically rapid induction clock component frequency ( frq ). Light is transcriptionally controlled requires two cis-acting elements (LREs) in promoter. Both LREs are bound a White Collar–1 (WC-1)/White Collar–2 (WC-2)–containing complex (WCC), causes decreased mobility WCC to LREs. The use vitro–translated WC-1 WC-2...
Circadian rhythmicity is universally associated with the ability to perceive light, and oscillators (“clocks”) giving rise these rhythms, which are feedback loops based on transcription translation, reset by light. Although such must contain elements of positive negative regulation, clock genes analyzed date— frq in Neurospora per tim Drosophila —are only their biochemical functions largely inferred. The white collar–1 collar–2 genes, both global regulators photoresponses , encode DNA...
The Neurospora crassa photoreceptor Vivid tunes blue-light responses and modulates gating of the circadian clock. Crystal structures dark-state light-state reveal a light, oxygen, or voltage Per-Arnt-Sim domain with an unusual N-terminal cap region loop insertion that accommodates flavin cofactor. Photoinduced formation cystein-flavin adduct drives protonation to induce conformational change. A cysteine-to-serine substitution remote from adenine dinucleotide binding site decouples switching...
Genome biology approaches have made enormous contributions to our understanding of biological rhythms, particularly in identifying outputs the clock, including RNAs, proteins, and metabolites, whose abundance oscillates throughout day. These methods hold significant promise for future discovery, when combined with computational modeling. However, genome-scale experiments are costly laborious, yielding “big data” that conceptually statistically difficult analyze. There is no obvious consensus...
Low rates of homologous recombination have broadly encumbered genetic studies in the fungal pathogen Aspergillus fumigatus. The CRISPR/Cas9 system bacteria has recently been developed for targeted mutagenesis eukaryotic genomes with high efficiency and, importantly, through a mechanism independent repair machinery. As this new technology not use A. fumigatus, we sought to test its feasibility gene disruption organism. proof principle, first demonstrated that can indeed be used...
In Neurospora crassa , white collar 1 (WC-1), a transcriptional activator and positive clock element, is rhythmically expressed from nonrhythmic steady-state pool of wc-1 transcript, consistent with posttranscriptional regulation rhythmicity. Mutations in frq influence both the level periodicity WC-1 expression, driven FRQ expression not only depresses its own endogenous levels, but positively regulates synthesis lag about 8 hours, delay similar to that seen wild-type clock. thus plays dual...
To understand how light entrains circadian clocks, we examined the effects of on a gene known to encode state variable oscillator, frequency (frq) gene. frq is rapidly induced by short pulses visible light; clock resetting correlated with induction and blocked drugs that block synthesis protein or translatable RNA. The speed magnitude suggest this may be initial clock-specific event in resetting. Light overcomes negative autoregulation so expression can remain high constant light. These data...
The frequency(frq) gene encodes central components of the transcription/translation-based negative-feedback loop comprising core Neurospora circadian oscillator; posttranscriptional regulation associated with FRQ is surprisingly complex. Alternative use translation initiation sites gives rise to two forms whose levels peak 4–6 hr following frq transcript. Each form progressively phosphorylated over course day, thus providing a number temporally distinct products. kinetics these regulatory...
Two forms of FRQ, a central component the Neurospora circadian clock, arise through alternative in-frame initiation translation. Either form alone suffices for functional clock at some temperatures, but both are always necessary robust rhythmicity. Temperature regulates ratio FRQ by favoring different codons temperatures; when either codon is eliminated, temperature range permissive rhythmicity demon- strably reduced. This temperature-influenced choice translation-initiation site represents...
White collar-1 (WC-1) and white collar-2 (WC-2) are essential for light-mediated responses in Neurospora crassa, but the molecular mechanisms underlying gene induction roles of other real putative photoreceptors remain poorly characterized. Unsupervised hierarchical clustering genome-wide microarrays reveals 5.6% detectable transcripts, including several novel mediators, that either early or late light responsive. Evidence is shown photoreception absence dominant, here confirmed, collar...
To investigate the regulation of messenger RNA abundance by circadian clocks, genomic and complementary DNA libraries were screened with probes enriched, means sequential rounds subtractive hybridization, for sequences to transcripts specific either early morning or evening cultures Neurospora . Only two morning-specific genes identified through this protocol. blot analysis verified that arising from these oscillates a period 21.5 hours in clock wild-type strain 29 long-period mutant frq 7...
Circadian rhythms control many physiological activities. The environmental entrainment of involves the immediate responses clock components. Levels protein FRQ were measured in Neurospora at various temperatures; higher temperatures, amount oscillated around levels. Absolute amounts thus identified different times so temperature shifts corresponded to time without synthesis or turnover Moderate changes could dominate light-to-dark influence circadian timing. Temperature regulation components...
D Bell-Pedersen, J C Dunlap, and Loros Department of Biochemistry, Dartmouth Medical School, Hanover, New Hampshire 03755.