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.

Related Articles


"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 April 1, 2015 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 April 1, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Wednesday, April 1, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Lion Makes Surprise Comeback in Gabon

Lion Makes Surprise Comeback in Gabon

AFP (Apr. 1, 2015) — The noble lion has made a comeback in southeast Gabon, after disappearing for years, according to US wildlife organisation Panthera, which recently took live video footage of a male. Duration: 00:32 Video provided by AFP
Powered by NewsLook.com
Liberia Sees Resurgence of Drug Trafficking as Ebola Wanes

Liberia Sees Resurgence of Drug Trafficking as Ebola Wanes

AFP (Apr. 1, 2015) — The governments of Liberia and Sierra Leone have been busy fighting the menace created by the deadly Ebola virus, but illicit drug lords have taken advantage of the situation to advance the drug trade. Duration: 01:12 Video provided by AFP
Powered by NewsLook.com
Gorilla Falls Into Zoo Moat

Gorilla Falls Into Zoo Moat

Reuters - Light News Video Online (Mar. 31, 2015) — A gorilla comes to the rescue of her sister who fell into a moat in Israel&apos;s Safari zoo. Rough cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
California on Alert Over Surge in Sea Lion Strandings

California on Alert Over Surge in Sea Lion Strandings

AFP (Mar. 31, 2015) — Since the start of the year, thousands of baby sea lions have washed up on beaches along the west coast of the United States. Marine animal care centers are working around the clock to save the stranded creatures. Duration: 02:06 Video provided by AFP
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