Navigation Links
Observing live gene expression in the body

Most of our physiological functions fluctuate throughout the day. They are coordinated by a central clock in the brain and by local oscillators, present in virtually every cell. Many molecular gearwheels of this internal clock have been described by Ueli Schibler, professor at the Faculty of Science of the University of Geneva (UNIGE), Switzerland. To study how the central clock synchronizes subordinate oscillators, the researcher's group used a variety of genetic and technological tools developed in collaboration with a team of UNIGE physicians. In this way, the scientists were able to directly observe the bioluminescence emitted by 'clock genes' in mice for several months. This biotechnology is applicable to numerous sectors of biomedical research, which attracted the attention of the editors from the journal "Genes & Development".

In mammals, there are many behaviors and biological functions that are regulated by internal clocks. Most of our cells have one, made from a family of 'clock genes', whose cyclic activity reaches a specific peak in 24 hours. These local oscillators are synchronized by a central 'pacemaker' in the brain which adjusts to light.

The firefly lights the way

The use of genetic engineering techniques enabled the study of molecular mechanisms that activate clock genes directly in cultured mammalian cells: 'We have coupled several of these genes to that of luciferase, the enzyme used by the female firefly for producing green light to attract males,' explained Ueli Schibler, member of the National Research Center Frontiers in Genetics. When a specific clock gene is activated in a cell that was transformed in this way, the light signal emitted can be measured using a highly sensitive bioluminescence detector. However, this device, which is capable of detecting signals on the order of a few photons, cannot be used for studying whole organisms. The contribution of Andr Liani's mechanical workshop, along with Jean-Pierre Wolf's and Luigi Bonacina's teams from UNIGE's Group of Applied Physics, was thus essential. These scientists developed a customized device that can accommodate mice for several months: 'We equipped it with reflective walls to deflect photons toward a highly sensitive photomultiplier tube to capture bioluminescence,' says Andr Liani.

Follow the daily expression of clock genes live

In collaboration with the University of Ulm and the Center for Integrative Genomics (CIG) of Lausanne, the biologists studied how the central clock synchronizes subordinate oscillators in mice. Various clock genes, coupled with the luciferase gene for light emission, were inserted into liver cells using a molecular vector. The time these rodents spent in the bioluminescent device allowed to demonstrate that the central clock generates signals, some of which act directly on the liver oscillators, and others which synchronize them indirectly by controlling the cycles of food intake.

or the effect of a medication in mice

'This technology enables a drastic reduction in the number of mice needed for this type of experiment, and furthermore, it is applicable to many areas of biomedical research,' says Camille Saini, researcher in the Department of Molecular Biology at UNIGE and first author of this article. These complementary genetic and engineering technology tools could be used to directly follow certain biochemical effects of metabolites like cholesterol or glucose, as well as the response to potential treatments of diseases such as hypercholesterolemia or diabetes. Monitoring the response to various hormones, neurotransmitters and other biochemical messengers is also part of this application range.


Contact: Ueli Schibler
Universit de Genve

Related biology news :

1. IU biologists offer clearer picture of how protein machine systems tweak gene expression
2. A new application allows online statistical analysis of gene-expression data
3. Measuring progesterone receptor expression to improve hormone-receptor-positive cancer management
4. Fish show autism-like gene expression in water with psychoactive pharmaceuticals
5. Controlling gene expression with hydrogen peroxide switches
6. Molecular economics: New computer models calculate systems-wide costs of gene expression
7. Controlling gene expression: How chromatin remodelers block a histone pass
8. Study finds how BPA affects gene expression, anxiety; Soy mitigates effects
9. Nutrient in eggs and meat may influence gene expression from infancy to adulthood
10. Whitehead scientists identify major flaw in standard approach to global gene expression analysis
11. Oxidative stress and altered gene expression occurs in a metabolic liver disease model
Post Your Comments:
(Date:10/6/2015)... , Oct. 6, 2015  Maverix Biomics, Inc., ... enhancements to its software portfolio with the debut ... for differential expression in eukaryotes. The software is ... a cloud-based genomic analysis solution that leverages proven ... from next-generation sequencing efforts. Garry Nolan,s ...
(Date:9/30/2015)... , Sept. 30, 2015  With nearly 300,000 Americans ... of new SCIs estimated to reach 12,500 annually, the ... California Resource Services for Independent Living (SCRS-IL) is ... California opening doors to independence ... programs and services, notably assistive technology services and education. ...
(Date:9/29/2015)... 2015  iDAvatars is excited to be named one of ... market. The official announcement was recently made at an invite-only ... San Francisco , where iDAvatars presented a ... Watson. "It is both an honor and a ... bring to market the cognitive power of IBM Watson in ...
Breaking Biology News(10 mins):
(Date:10/13/2015)... 2015  Cepheid (Nasdaq: CPHD ) today announced ... --> --> Based ... third quarter of 2015 is expected to be approximately ... to be approximately $(0.32) for the third quarter.  Based ... share for the third quarter of 2015 is expected ...
(Date:10/13/2015)... Applied BioMath ( ), a computational ... the drug invention process, announced that it will sponsor ... 20-22, 2015 in Boston , MA.  ... CEO of Applied BioMath, will present "QSP approaches enabling quantitative ... trials" on Wednesday October 21st 2015 at 12:30PM.  ...
(Date:10/13/2015)... YORK , October 13, 2015 ... acceleration and development company, has entered into a strategic ... York and Paris, France ... --> --> This collaborative arrangement ... highly respected scientific advisory team as well as long ...
(Date:10/13/2015)... ... ... Clinovo recently appointed Jeff Parr and Ed Donaldson to its Business Development ... , Jeff Parr has spent the past decade providing quality management software and consulting ... Ab Sciex to name a few. He is based in Salt Lake City, ...
Breaking Biology Technology: