scholarly journals Developmental Stage-Specific Regulation of the Circadian Clock by Temperature in Zebrafish

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Kajori Lahiri ◽  
Nadine Froehlich ◽  
Andreas Heyd ◽  
Nicholas S. Foulkes ◽  
Daniela Vallone

The circadian clock enables animals to adapt their physiology and behaviour in anticipation of the day-night cycle. Light and temperature represent two key environmental timing cues (zeitgebers) able to reset this mechanism and so maintain its synchronization with the environmental cycle. One key challenge is to unravel how the regulation of the clock by zeitgebers matures during early development. The zebrafish is an ideal model for studying circadian clock ontogeny since the process of development occursex uteroin an optically transparent chorion and many tools are available for genetic analysis. However, the role played by temperature in regulating the clock during zebrafish development is poorly understood. Here, we have established a clock-regulated luciferase reporter transgenic zebrafish line (Tg (−3.1)per1b::luc) to study the effects of temperature on clock entrainment. We reveal that under complete darkness, from an early developmental stage onwards (48 to 72 hpf), exposure to temperature cycles is a prerequisite for the establishment of self-sustaining rhythms ofzfper1b,zfaanat2, andzfirbpexpression and also for circadian cell cycle rhythms. Furthermore, we show that following the 5–9 somite stage, the expression ofzfper1bis regulated by acute temperature shifts.

2009 ◽  
Vol 7 (1) ◽  
pp. 138-150 ◽  
Author(s):  
Zhong Qin ◽  
Xin Deng

This paper explores the impact of ownership structure on performance of family businesses at its early developmental stage in a context of under-developed market environment. Using a survey data of 296 private family firms in Ningbo, China, we find both management and single largest shareholder’s ownership is positively related to firm’s performance. However, family’s shareholding does not have significant impact on performance. Further inquiry on firm’s willingness to give shares to managers who are not family members indicates that while nearly half of the firms are willing to provide shares to professional managers, weak corporate governance mechanism and under-developed market may discourage such practice.


2016 ◽  
Vol 419 (2) ◽  
pp. 217-228 ◽  
Author(s):  
Hiroko Torii ◽  
Atsuhiro Yoshida ◽  
Tatsuya Katsuno ◽  
Takayuki Nakagawa ◽  
Juichi Ito ◽  
...  

2006 ◽  
Vol 128 (3) ◽  
pp. 391-404 ◽  
Author(s):  
Alessandro Jaquiel Waclawovsky ◽  
Marcelo Ehlers Loureiro ◽  
Rejane do Livramento Freitas ◽  
Carolina da Silva Rocha ◽  
Marco Antonio Oliva Cano ◽  
...  

2007 ◽  
Vol 4 (1) ◽  
pp. 123-126 ◽  
Author(s):  
James F Gillooly ◽  
Gustavo A Londoño ◽  
Andrew P Allen

Biologists have long sought a means by which to quantify similarities and differences in embryonic development across species. Here we present a quantitative approach for predicting the timing of developmental events based on principles of allometry and biochemical kinetics. Data from diverse oviparous species support model predictions that most variation in the time required to reach one early developmental stage—the time to first heartbeat—is explained by the body size and temperature dependence of metabolic rate. Furthermore, comparisons of this stage with later developmental stages suggest that, after correcting for size and temperature, the relationship of metabolic rate to the rate of embryogenesis is approximately invariant across taxonomic groups and stages of ontogeny.


2016 ◽  
Vol 92 (1-2) ◽  
pp. 71-88 ◽  
Author(s):  
Tien Dung Nguyen ◽  
Sunok Moon ◽  
Van Ngoc Tuyet Nguyen ◽  
Yunsil Gho ◽  
Anil Kumar Nalini Chandran ◽  
...  

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