Featured Research

from universities, journals, and other organizations

Gene Breakthrough Heralds Better Prospect For Malaria Solution

Date:
July 25, 2006
Source:
University of Bath
Summary:
Scientists have made a major breakthrough in understanding the genetics of the insect parasite that is being targeted by researchers as a way of preventing the spread of malaria.

The image shows a fluorescent microscope image of a Drosophila embryo infected with Wolbachia. The embryo is about 0.5 mm long.
Credit: Image courtesy of University of Bath

Scientists have made a major breakthrough in understanding the genetics of the insect parasite that is being targeted by researchers as a way of preventing the spread of malaria.

Wolbachia bacteria are parasites that infect as many as 80 per cent of the world’s insects and manipulate reproduction in their hosts in order to improve their own transmission.

In species including the fruit fly and mosquito, they do this by altering the sperm of infected males to prevent them from successfully reproducing with uninfected females.

Females infected with Wolbachia produce, on average, more offspring than uninfected females.

This is because they can successfully mate with any male in the population, whereas uninfected females are restricted to uninfected males. As Wolbachia is maternally transmitted, this has the effect of spreading the infection through the insect population.

Researchers around the world have secured millions in research funding to help develop malaria control strategies that use genetically modified Wolbachia that would spread through mosquito populations and carry genes that make their mosquito hosts unable to transmit the plasmodium parasite that cause malaria.

For the first time, in new research published in the journal Genetics, scientists from the University of Bath (UK) and the University of Chicago (USA) have identified two of the genes that Wolbachia manipulates when it infects the fruit fly Drosophila simulans.

“This is a major breakthrough in our understanding of the genetic basis of Wolbachia infection,” said Dr Ben Heath, from the Department of Biology & Biochemistry at the University of Bath.

“In recent years there has been great interest in using transgenic Wolbachia as a way of modifying natural populations of insects such as mosquitoes which transmit malaria.

“However this would always be difficult to achieve without a full understanding of the genetics of how Wolbachia interacts with its host insect.

“Our discovery of two of the fruit fly genes manipulated by Wolbachia sheds light on this process, and we should now be able to develop a clearer picture of exactly how Wolbachia manipulate the reproductive process in a variety of its hosts.

“Part of the problem in studying Wolbachia is that it lives inside the cells of its host insect and cannot effectively be studied on its own because it needs the cellular machinery and materials it gets from its host to survive.

“Another difficulty is that the changes it makes in the development of sperm are so subtle that they can be difficult to trace.”

In their research the scientists compared the genes that were being expressed – switched on - in infected and uninfected male fruit flies. By subtracting one from the other, they were left with the genes that were being expressed as a result of the Wolbachia infection.

One of the genes they identified, called zipper, is well known to scientists but has never been associated with Wolbachia infection before.

“Infected males have increased expression of their zipper gene compared to those that are uninfected,” said Dr Tim Karr, also from the University of Bath, who led the research.

“We were then able to work with transgenic flies which express the zipper gene more when warmed up slightly for periods of one hour during their development.

“This doesn’t harm the flies and provides an opportunity to mimic the effect of Wolbachia in fruit flies that don’t carry the bacteria.

“The zipper gene identified by the scientists also interacts with a second gene called lgl which is responsible for polarity within the cell and this becomes important when a cell divides into two different cells, such as when stem cells develop into sperm.

“By affecting the balance between these genes, it appears Wolbachia can promote cytoplasmic incompatibility by modifying the sperm of infected males.

“This prevents the sperm from being compatible with any egg from a female not infected with Wolbachia and results in sterility.

“However when infected males mate with infected females, the Wolbachia in the egg finds a way of correcting the modification to sperm and allows fertilization and normal development to continue.”

The researchers are now looking at the mechanisms present in other insect species with different levels of cytoplasmic incompatibility

In other insects Wolbachia infection has diverse and often dramatic results which all cause an increase in Wolbachia transmission for the simple reason that these bacteria are only transmitted through the maternal line, from mother to daughter.

In two–spot ladybirds Wolbachia kill male offspring leaving the surviving sisters to eat the bodies of their dead brothers, in woodlice, infected males are turned into females, and infected parasitic wasps give birth without reproducing.

These reproductive effects are what made Wolbachia so fascinating to biologists in the first place and now they may also provide new ways of tackling insect-bourne diseases such as malaria.

The research was funded by the Biotechnology and Biological Sciences Research Council (UK), the Royal Society (UK) and the National Science Foundation (USA).


Story Source:

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


Cite This Page:

University of Bath. "Gene Breakthrough Heralds Better Prospect For Malaria Solution." ScienceDaily. ScienceDaily, 25 July 2006. <www.sciencedaily.com/releases/2006/07/060725084640.htm>.
University of Bath. (2006, July 25). Gene Breakthrough Heralds Better Prospect For Malaria Solution. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2006/07/060725084640.htm
University of Bath. "Gene Breakthrough Heralds Better Prospect For Malaria Solution." ScienceDaily. www.sciencedaily.com/releases/2006/07/060725084640.htm (accessed September 17, 2014).

Share This



More Plants & Animals News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

AFP (Sep. 16, 2014) Since the arrival of Ebola in Ivory Coast, Ivorians have been abandoning their pets, particularly monkeys, in the fear that they may transmit the virus. Duration: 00:47 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:
from the past week

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