Circadian surprise: Mechanism of temperature synchronization in drosophila

Oct 28, 2009

New research reveals a pathway that links peripheral sensory tissues with a "clock" in the brain to regulate molecular processes and behaviors in response to cyclical temperature changes. The research, published by Cell Press in the October 29th issue of the journal Neuron, reveals some surprising fundamental differences between how light-dark and temperature cycles synchronize the brain clock of the fruit fly, Drosophila.

A variety of organisms have evolved an endogenous timing system called a to regulate behavioral metabolic activities. "Circadian clocks regulate many biological processes to occur at beneficial times for the organism," explains senior study author, Dr. Ralf Stanewsky from Queen Mary College at the University of London. "Although we know quite a bit about how natural light-dark cycles synchronize the circadian clock of organisms ranging from flies to mammals, little is known about mechanisms of temperature synchronization."

Specifically, it is not known which cells or structures sense temperature changes or how temperature signals reach the brain clock. In an earlier study, Dr. Stanewsky and colleagues identified two in the that interfered with temperature synchronization. One of the genes, nocte, was defective in flies that exhibited normal light synchronization but abnormal molecular and behavioral synchronization to temperature.

In the current study, the researchers found that isolated fly brains were able to synchronize to light-dark cycles but were unable to synchronize to temperature cycles. This suggested that in contrast to light-dark synchronization, the brain circadian clock require information from peripheral tissues for temperature synchronization. Importantly, disruption of nocte in peripheral cells also interfered with temperature synchronization.

More specifically, loss of nocte changed the structure and function of major fly sensory organs called chordotonal organs, and had a dramatic influence on temperature synchronization of behavioral activity. Further, other mutants that interfered with the function of the chordotonal organs also disrupted temperature synchronization. This established the chordotonal organs as key circadian temperature receptors.

"Our work reveals surprising and important mechanistic differences between light- and temperature-synchronization and advances our understanding of how clock resetting is accomplished in nature," offers Dr. Stanewsky. "This study demonstrates once again the power of forward genetics in identifying novel factors and mechanisms. Just looking at the nocte DNA sequence, no one would have predicted a function for this gene or the chordotonal organs in temperature synchronization".

Source: Cell Press (news : web)

Explore further: The origin of the language of life

add to favorites email to friend print save as pdf

Related Stories

Recommended for you

The origin of the language of life

Dec 19, 2014

The genetic code is the universal language of life. It describes how information is encoded in the genetic material and is the same for all organisms from simple bacteria to animals to humans. However, the ...

Quest to unravel mysteries of our gene network

Dec 18, 2014

There are roughly 27,000 genes in the human body, all but a relative few of them connected through an intricate and complex network that plays a dominant role in shaping our physiological structure and functions.

EU court clears stem cell patenting

Dec 18, 2014

A human egg used to produce stem cells but unable to develop into a viable embryo can be patented, the European Court of Justice ruled on Thursday.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.