Temperature Effects on the Resetting of the Phase of the Neurospora Circadian Rhythm

Gooch, Van D.; Wehseler, Richard A.; Gross, Cristin G.

doi:10.1177/074873049400900108

Cited by 35 publications

(32 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the phase-resetting experiments, a large number of data points were gathered to generate a high degree of confidence in measurements that would have been much more labor-intensive with conventional race tube assays. We see strong phase-resetting effects ("type 0") with 1-h pulses of temperatures higher than 31°C, and the transition from "type 1" to "type 0" resetting seems to occur at about 31°C, consistent with previous temperature data on Neurospora (23,25).…”

Section: Vol 7 2008supporting

confidence: 90%

Fully Codon-Optimized luciferase Uncovers Novel Temperature Characteristics of the Neurospora Clock

et al. 2008

Self Cite

View full text Add to dashboard Cite

We report the complete reconstruction of the firefly luciferase gene, fully codon optimized for expression in Neurospora crassa. This reporter enhances light output by approximately 4 log orders over that with previously available versions, now producing light that is visible to the naked eye and sufficient for monitoring the activities of many poorly expressed genes. Time lapse photography of strains growing in race tubes, in which the frq or eas/ccg-2 promoter is used to drive luciferase, shows the highest levels of luciferase activity near the growth front and newly formed conidial bands. Further, we have established a sorbose medium colony assay that will facilitate luciferase-based screens. The signals from sorbose-grown colonies of strains in which the frq promoter drives luciferase exhibit the properties of circadian rhythms and can be tracked for many days to weeks. This reporter now makes it possible to follow the clock in real time, even in strains or under conditions in which the circadian rhythm in conidial banding is not expressed. This property has been used to discover short, ca. 15-h period rhythms at high temperatures, at which banding becomes difficult to observe in race tubes, and to generate a high-resolution temperature phase-response curve.Circadian rhythmicity is an ancient form of biological regulation. The ability of an organism to determine the time of day in order to regulate metabolic events is close to ubiquitous within the eukaryotes and, additionally, is found in more than one cyanobacterial species (17). Although the ability to tell time from a molecularly based oscillator is thematically conserved across many phyla, the outputs that the circadian clock regulates are organismally dependent, and in many systems, reporters are used to monitor these rhythms. There is a rich history of using luminescence for this purpose in circadian biology. Studies using circadianly regulated endogenous luciferase in the marine dinoflagellate Gonyaulax polyedra to follow the clock (34) were precursors for a host of experiments using luminescent reporters in plants (35

show abstract

Section: Vol 7 2008supporting

confidence: 90%

Fully Codon-Optimized luciferase Uncovers Novel Temperature Characteristics of the Neurospora Clock

et al. 2008

Self Cite

View full text Add to dashboard Cite

show abstract

“…1B). Although the new phases were set to close to the high point of the FRQ oscillation, they were nonetheless somewhat dependent on the old phase, which was consistent with previous studies (9,10). Temperature step-downs are not just a mirror image of step-ups.…”

Section: How Temperature Changes Reset a Circadian Oscillatorsupporting

confidence: 78%

“…Circadian clocks can be extremely sensitive to temperature changes; in insects, lizards, and fungi, clocks can be entrained by temperature cycles that oscillate only 1°to 2°C (14 -16 ). Temperature effects on the Neurospora circadian system, in particular, are well described (9,10,16 ), as is the general pattern in which molecular components are assembled, forming a feedback loop that is central to the system (1,3,17,18). We have sought to understand how a day-phase oscillator that is characteristic of many eukaryotes could be reset by temperature steps.…”

Section: How Temperature Changes Reset a Circadian Oscillatormentioning

confidence: 99%

“…The same absolute amount of FRQ must correspond to different circadian times at different temperatures; therefore, when a cell is transferred from one temperature to another, the clock will be reset to the subjective time that corresponds to the actual amount of FRQ in the cell as viewed in the context of the new temperature. The size of temperature step-induced phase shifts is a function of the circadian time and the magnitude of the temperature treatments (9,10,16), and large temperature steps elicit strong resetting (16), moving the phase of the clock to a restricted part of the circadian day; temperature step-ups reset the clock to about circadian time (CT) 0 (subjective dawn), and temperature step-downs reset the phase to between CT9 and CT12 (subjective dusk) (Fig. 1, B and C) (9,10,16 ).…”

Section: How Temperature Changes Reset a Circadian Oscillatormentioning

confidence: 99%

See 1 more Smart Citation

How Temperature Changes Reset a Circadian Oscillator

Liu

Merrow

Loros

et al. 1998

Science

213

184

View full text Add to dashboard Cite

Circadian rhythms control many physiological activities. The environmental entrainment of rhythms involves the immediate responses of clock components. Levels of the clock protein FRQ were measured in Neurospora at various temperatures; at higher temperatures, the amount of FRQ oscillated around higher levels. Absolute FRQ amounts thus identified different times at different temperatures, so temperature shifts corresponded to shifts in clock time without immediate synthesis or turnover of components. Moderate temperature changes could dominate light-to-dark shifts in the influence of circadian timing. Temperature regulation of clock components could explain temperature resetting of rhythms and how single transitions can initiate rhythmicity from characteristic circadian phases.

show abstract

“…; the period of the rhythm is temperature compensated (Qlo N 1) between 18 and 30 OC (Nakashima & Feldman, 1980); and the rhythm can be entrained by various light-dark cycles (Sargent et al, 1966; Nakashima & Feldman, 1980 ;Dharmananda, 1980) and reset by temperature pulses (Francis & Sargent, 1979;Gooch et al, 1994;Rensing et al, 1995 To monitor the phenotypic expression of the Neurospora clock, conidia are inoculated at one end of a race tube. Race tubes are hollow glass tubes about 40cm long and 16mm in diameter that are bent upwards at both ends to hold an agar medium.…”

Section: )mentioning

confidence: 99%

Keeping pace with Neurospora circadian rhythms

Bell-Pedersen

1998

Microbiology

View full text Add to dashboard Cite

Daily (circadian) rhythms in biochemical, cellular and behavioural activities are observed in organisms as diverse as algae, fungi, fruit flies, mice and humans. A remarkable feature of these rhythms is that they are not simply a response to 24 h environmental cycles imposed by the Earth's rotation, but instead are generated internally by cell autonomous biological clocks. Circadian clocks allow organisms to predict and prepare for the changes that occur in the physical world and afford the ability to temporally coordinate and partition cellular activities to appropriate times of the day. Thus the circadian clock not only provides an interesting biological problem with which to study, but also grants a unique opportunity to investigate how a cellular phenomenon is adapted to the environment, ultimately resulting in specific behavioural patterns.

show abstract

Temperature Effects on the Resetting of the Phase of the Neurospora Circadian Rhythm

Cited by 35 publications

References 25 publications

Fully Codon-Optimized luciferase Uncovers Novel Temperature Characteristics of the Neurospora Clock

Fully Codon-Optimized luciferase Uncovers Novel Temperature Characteristics of the Neurospora Clock

How Temperature Changes Reset a Circadian Oscillator

Keeping pace with Neurospora circadian rhythms

Contact Info

Product

Resources

About