Navigation Links
New models question old assumptions about how many molecules it takes to control cell division
Date:2/24/2009

ons in the number of molecules being created or destroyed at any given moment."

Nonetheless, the ebb and flow of molecules in a cell must reliably convey instructions for such essential processes as DNA replication and cell division.

How big are the molecular fluctuations expected in a single yeast cell? Physicists estimate molecular fluctuation using a rule-of-thumb that the size of typical fluctuations is the square root of the average number of molecules. "If there are on average 900 molecules of a particular protein in a cell, then we can expect fluctuations of plus or minus 30 molecules, or 3.3 percent," said Tyson. "That is not too bad."

For DNA there might be a severe problem, Tyson noted, "because there is only one copy of every gene in a yeast cell. But cells are equipped with an elaborate and expensive mechanism to replicate DNA molecules and not allow the random fluctuations predicted by statistical physics."

The weak link in the is mRNA: the molecule that carries information from the gene to the cell's ribosomes, where proteins are made.

The literature reports that there is on average only 1 mRNA molecule per gene per cell, in yeast, and that each mRNA molecule lives, on average, for 15 to 20 minutes before it is degraded. "This is intriguing," said Tyson, "because the physicist's rule-of-thumb would predict very large fluctuations in mRNA abundance sometimes 1, sometimes 0, sometimes 2 or 3 or 4 -- which means the noise among mRNA molecules is huge, and it propagates to the level of the encoded protein."

The noisy fluctuations in protein level may be 50 percent instead of 3 percent. "There is no way the control system can work in the face of such large fluctuations," Tyson said. "It would be completely unreliable."

Progression through the cell cycle is indeed a noisy process, with typical flucutations of 15 to 20 percent for the time taken to complete the process. To achieve this level
'/>"/>

Contact: Susan Trulove
STrulove@vt.edu
540-231-5646
Virginia Tech
Source:Eurekalert

Page: 1 2 3

Related biology news :

1. Bacteria are models of efficiency
2. David Rose to present Howe School lecture on new technologies and business models, Jan. 29
3. Models simulate nitrate dynamics in Garonne, Southwest France
4. New movement models tested at the Smithsonian in Panama
5. Swamping bad cells with good in ALS animal models helps sustain breathing
6. Models of eel cells suggest electrifying possibilities
7. In computer models and observations, researchers see potential for significant red tide season
8. Arctic climate models playing key role in polar bear decision
9. Smithsonian researchers develop models to assess wetland health
10. Similar survival rates for Pacific salmon in Fraser, Columbia Rivers raises new questions
11. Study of polar dinosaur migration questions whether dinosaurs were truly the first great migrators
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/17/2014)... in the Cell Press journal Current Biology ... rather novel sex lives. The Brazilian insects, which represent ... Neotrogla , are the first example of an animal ... been identified in several different animals, Neotrogla ... is also reversed," says Kazunori Yoshizawa from Hokkaido University ...
(Date:4/17/2014)... Gene expression is the process whereby the genetic ... products, such as proteins, which have numerous different ... as an important intermediary during gene expression, by ... molecular mechanisms involved in manufacturing proteins. , ... mRNA molecules present in an organism at a ...
(Date:4/17/2014)... chock full of wild animals and plant life, but ... are churning away in the soil, decomposing organic matter ... vital role these fungi play in ecological systems, their ... of scientists has generated a genetic map of more ... work was published this week in the Proceedings ...
Breaking Biology News(10 mins):In sex-reversed cave insects, females have the penises 2Rapid and accurate mRNA detection in plant tissues 2Stanford biologists help solve fungal mysteries 2Stanford biologists help solve fungal mysteries 3
... in awe of what their football heroes can do with ... mysterious. Although being in excellent physical condition undoubtedly helps, few ... an average bloke into a Ronaldo. Now, scientists from the ... else" might be. Dr. Robbie Wilson will talk about the ...
... forming rainforest canopies bear little resemblance to their seedlings, ... field guide, "Seedlings of Barro Colorado Island and the ... Author Nancy Garwood, professor of plant biology at the ... task of describing seedling stages of tropical plants 25 ...
... The Stowers Institute,s Xie Lab has revealed how the ... it is involved in regulating the quality of stem ... by PNAS Early Edition. Maintaining the proper ... for normal homeostasis. An imbalance between the two can ...
Cached Biology News:What makes a great footballer? 2New guide to tropical seedlings: Essential to climate change research 2Xie Lab uncovers molecular machinery related to stem cell fate 2
(Date:1/15/2014)... Hills, IL (PRWEB) January 15, 2014 ... to find hard-working items for the lab, from fluid ... as Guaranteed-in-Stock (GIS)—ready to ship when you order. ... Masterflex® Peristaltic Pumps , from the L/S® model for ...
(Date:1/15/2014)... RedBrick Health , a fast-growing leader in consumer ... EmblemHealth , the New York ... the RedBrick Compass health assessment, combined with the RedBrick ... members. EmblemHealth is among the first health plans in ...
(Date:1/15/2014)... (PRWEB) January 15, 2014 More than ... and about 1 in 3 seniors will die with ... ). These jaw-dropping figures have shocked many Americans into ... hopefully, help prevent these tragic age-related cognitive disorders. Jonathan ...
(Date:1/15/2014)... DTS Language Services, Inc . is pleased to announce ... organizations who need document translations. Clients will now have ... in advance with a selection of nearly 50 life science ... critical factor in clinical and scientific fields, and decrease the ...
Breaking Biology Technology:Cole-Parmer Begins 2014 with the Release of Preferred Solutions 2EmblemHealth Selects RedBrick Health to Power its Next-Generation Health Engagement and Behavior Change System 2EmblemHealth Selects RedBrick Health to Power its Next-Generation Health Engagement and Behavior Change System 3Biohack Pure Offers 5 Tips for Increasing Memory in 2014 2DTS Improves Efficiency for Life Science Document Translations 2
... Researchers at Duke University Medical Center, Beth Israel Deaconess ... to HIV vaccine design that uses an altered form of ... researchers showed that they could design HIV envelopes that could ... enhanced immune response in an animal model. Immature B cells ...
... new paradigm in quantum information processing has been demonstrated ... published in this week,s issue of Science Express ... integrated circuit that implements the quantum von Neumann architecture. ... can be programmed using a quantum central processing unit, ...
... Md., Sept. 1, 2011 Neuralstem, Inc. (NYSE Amex: ... Richard Garr will present at the 2011 Stifel Nicolaus ... a.m. EDT. Garr will discuss the Company,s opportunities and ... and will be providing an update on the ongoing ...
Cached Biology Technology:New HIV vaccine approach targets desirable immune cells 2New HIV vaccine approach targets desirable immune cells 3Neuralstem President and CEO to Present at the 2011 Stifel Nicolaus Annual Healthcare Conference 2Neuralstem President and CEO to Present at the 2011 Stifel Nicolaus Annual Healthcare Conference 3
... PowerPac basic power supply are used for submerged ... gels. The Mini-Sub cell GT cell includes a ... 7 x 7 cm UV-transparent gel tray with ... mm fixed-height combs (8- and 15-well). The PowerPac ...
... PowerPac basic power supply are used for submerged ... gels. This Model 96 cell includes a buffer ... tray with fluorescent ruler, and a gel caster. ... V, provides output of 10-300 V, 4-400 mA, ...
... The Sub-Cell Model 192 and PowerPac basic power ... of nucleic acids in agarose gels. This Model ... x 15 cm UV-transparent gel tray with fluorescent ... power supply, 100-120 and 220-240 V, provides output ...
... The Sequi-Gen GT and PowerPac 3000 system, ... using a 38 x 30 cm vertical slab ... GT electrophoresis cell, which is capable of separating ... an integral plate chamber (IPC) assembly (IPC and ...
Biology Products: