Featured Research

from universities, journals, and other organizations

Nano-channel disentangles knotted DNA

Date:
February 20, 2013
Source:
Sissa Medialab
Summary:
DNA, just like hair, has a tendency to become knotted, thus it may be useful to disentangle it. Unfortunately, it is not possible to “actively” choose at random (or better, in one solution) the filaments with the desired features, and this is why scientists adopt “passive” solutions like, for instance, having the DNA pass through nano-pores or nano-channels.

Knotted DNA.
Credit: Image courtesy of Sissa Medialab

DNA, just like hair, has a tendency to become knotted, thus it may be useful to disentangle it. Unfortunately, it is not possible to "actively" choose at random (or better, in one solution) the filaments with the desired features, and this is why scientists adopt "passive" solutions like, for instance, having the DNA pass through nano-pores or nano-channels.

"Channels and filaments have physical features we may exploit to selectively let a type of molecule pass through" explains Micheletti. "You can have more or less entangled filaments and featuring knots of different types. In our study we have considered a specific DNA filament model and examined its behavior within a nano-channel. We have observed that by varying the channel's width it is possible to drastically change the quantity and complexity of the knots formed by the DNA."

The nano-channels may therefore be a tool with a double function: on one side they are used to understand the "knotting pattern" of a DNA fragment, on the other they may be used to select entangled filaments in the desired manner. The sectors employing DNA, mainly in sequencing, require an increasing number of new techniques to select the DNA filaments according to their characteristics, such as length, shape as well as entanglement.

"Experimental physicists will be, in the first instance, interested is such technique to obtain knot-free DNA," explains Micheletti referring to the usefulness of the methodology (that for now has been studied through simulation). "We should not forget that such method may also help us better understand, for instance, the functioning of topoisomerases, enzymes that have a very important role in cell metabolism." Such enzymes play a key role in an organism: they maintain the DNA stretched out when the cell is not undergoing the cell division process.

"We are used to envisage chromosomes in their typical rod shaped appearance, the one preceding mitosis, that is to say cell reproduction," adds Micheletti. "However, usually the DNA is a sort of indistinct bundle that fills up the cell's nucleus. The topoisomerases maintain the disentangled filaments with the lowest possible rate of knotting, and do so by snipping and reattaching the little pieces of genetic material." Only on the "disentangled" filament all those transcription processes which are fundamental to the survival of an organism can actually function. "The functioning of such enzymes may be better grasped if, before having them perform, we already know to what extent the molecule was entangled in the first place, and our methodology may be useful to this purpose." concludes Micheletti.


Story Source:

The above story is based on materials provided by Sissa Medialab. Note: Materials may be edited for content and length.


Journal Reference:

  1. Cristian Micheletti, Enzo Orlandini. Knotting and metric scaling properties of DNA confined in nano-channels: a Monte Carlo study. Soft Matter, 2012; 8 (42): 10959 DOI: 10.1039/C2SM26401C

Cite This Page:

Sissa Medialab. "Nano-channel disentangles knotted DNA." ScienceDaily. ScienceDaily, 20 February 2013. <www.sciencedaily.com/releases/2013/02/130220084707.htm>.
Sissa Medialab. (2013, February 20). Nano-channel disentangles knotted DNA. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2013/02/130220084707.htm
Sissa Medialab. "Nano-channel disentangles knotted DNA." ScienceDaily. www.sciencedaily.com/releases/2013/02/130220084707.htm (accessed October 20, 2014).

Share This



More Plants & Animals News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
Goliath Spider Will Give You Nightmares

Goliath Spider Will Give You Nightmares

Buzz60 (Oct. 20, 2014) An entomologist stumbled upon a South American Goliath Birdeater. With a name like that, you know it's a terrifying creepy crawler. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
Powered by NewsLook.com
Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins