Fundamental Limits to Position Determination by Concentration Gradients

نویسندگان

  • Filipe Tostevin
  • Pieter Rein ten Wolde
  • Martin Howard
چکیده

Position determination in biological systems is often achieved through protein concentration gradients. Measuring the local concentration of such a protein with a spatially varying distribution allows the measurement of position within the system. For these systems to work effectively, position determination must be robust to noise. Here, we calculate fundamental limits to the precision of position determination by concentration gradients due to unavoidable biochemical noise perturbing the gradients. We focus on gradient proteins with first-order reaction kinetics. Systems of this type have been experimentally characterised in both developmental and cell biology settings. For a single gradient we show that, through time-averaging, great precision potentially can be achieved even with very low protein copy numbers. As a second example, we investigate the ability of a system with oppositely directed gradients to find its centre. With this mechanism, positional precision close to the centre improves more slowly with increasing averaging time, and so longer averaging times or higher copy numbers are required for high precision. For both single and double gradients, we demonstrate the existence of optimal length scales for the gradients for which precision is maximized, as well as analyze how precision depends on the size of the concentration-measuring apparatus. These results provide fundamental constraints on the positional precision supplied by concentration gradients in various contexts, including both in developmental biology and also within a single cell.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Electrocatalytic Determination of Isoniazid by a Glassy Carbon Electrode Modified with Poly (Eriochrome Black T)

In this work poly eriochrome black T (EBT) was electrochemically synthesized on the glassy carbon electrode as electrode modifier. On the modified electrode, voltammetric behavior of isoniazid (INH) was investigated. The poly (EBT)-modified glassy carbon electrode has excellent electrocatalytic ability for the electrooxidation of isoniazid. This fact was appeared as a reduced overpotential of I...

متن کامل

Sepration and determination trace amount of cadmium ions in real and water samples by cloud point extraction - flame atomic absorption spectrophotometry after preconcentration with non-ionic surfactant Triton-X114

2-(3- indolyl) – 4,5 di phynyl imidazole.(IDPI) was used as a complexing agent in cloud point extraction for the first time and applied for selective pre-concentration of trace amounts of cadmium. The method is based on the extraction of cadmium at pH= 7.0 by using non-ionic surfactant Triton-X114 and 2-(3- indolyl) – 4,5 di phynyl imidazole. (IDPI) as a chelating agent. The adopted concentrati...

متن کامل

Determination of lethal concentration (LC50) values

In this study, lethal concentration (LC50) values of cinnamon hydrosol (Cinnamomum zeylanicum) on carp (Cyprinus carpio) were investigated. In practice, experimental setup was constituted 30 fish (a total of 180 fish with 30 control fish) to be placed in three replicates. Hydrosol was added into aquariums at the doses of 0.5, 1, 2.5, 5 and 10% and determined mortality times of carp exposed to t...

متن کامل

Fundamental Limits of Wideband Localization - Part II: Cooperative Networks

The availability of position information is of great importance in many commercial, governmental, and military applications. Localization is commonly accomplished through the use of radio communication between mobile devices (agents) and fixed infrastructure (anchors). However, precise determination of agent positions is a challenging task, especially in harsh environments due to radio blockage...

متن کامل

Determination of Sitagliptin Phosphate in Bulk Drugs by Extractive Spectrophotometric Method

An extractive spectrophotometric method is described for the assay of sitagliptin phosphate in bulk drug and in tablets. Sitagliptin phosphatewas extracted as an ion-pair complex from the solution containing Eriochrome black T and 0.1N HCl into chloroform and the absorbance of the complex was measured at 500nm.The working conditions of the method were investigated and optimized. Beer’s law plot...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • PLoS Computational Biology

دوره 3  شماره 

صفحات  -

تاریخ انتشار 2007