A scourge of rural Africa, the tsetse fly is genetically deciphered


April 25, 2014
Health, Life & Non-humans

An international team of researchers led by the Yale School of Public Health has successfully sequenced the genetic code of the tsetse fly, opening the door to scientific breakthroughs that could reduce or end the scourge of African sleeping sickness in sub-Saharan Africa. The study is published in the journal Science.

It took nearly 10 years and more than 140 scientists from numerous countries to map the genome of the fly, also known as Glossina morsitans. Tsetse flies are the sole insect vectors of a disease that threatens the health of millions of people and devastates livestock herds.

The genetic blueprint will provide researchers with the codes for the proteins that make up the tsetse fly, which is slightly larger than a common housefly. It is essentially a “parts list” of what the organism is made from. Access to the blueprint is expected to accelerate research into the tsetse fly’s unique biology and promote the development of improved tsetse control methods as well as the development of new control strategies.

“This is a major milestone for the tsetse research community,” said Geoffrey M. Attardo, a research scientist at the Yale School of Public Health and the paper’s lead author. “Our hope is that this resource will facilitate functional research and be an ongoing contribution to the vector biology community.” The effort has already resulted in eight research articles that expand on the genome data using functional genomics methods and are being published under the banner “Tsetse Genome Biology Collection” in the PLOS-wide journals.

While there are drugs to combat sleeping sickness, they are expensive, have many undesirable side effects, and are difficult to administer in wide swaths of rural Africa where the disease is most pronounced. Left untreated, sleeping sickness is 100% fatal.

The researchers had to overcome numerous challenges — technical, biological and economic — in order to decipher the complete sequence. As with most genome projects the researchers had to limit their analysis to a single genetic line in order to improve the assembly of small fragments of sequence data — thousands of letters of code — into large scaffolds that contain millions of letters of code. This became an issue because only a small amount of genetic material is obtainable from each fly, and unlike other insects, one tsetse female gives birth to very few offspring. The genome contains approximately 366 million letters of code, which is equivalent to about 10% of those in the human genome.

School of Public Health professor Serap Aksoy helped initiate the collaborative research project in the early 2000s when she and a small group of other researchers concluded that progress against the disease and new tsetse-based control opportunities would be stymied unless the biological and chemical underpinnings of the organism were completely understood. The consortium was initiated with seed funding from the World Health Organization. “We are very happy to finally reach the finish line,” Aksoy said. “Our hope is that tsetse research will now enjoy broader participation from the vector community and lead to improved and novel methods to eliminate disease.”


4 Responses to A scourge of rural Africa, the tsetse fly is genetically deciphered

  1. Annette Opperman (14005582) April 30, 2014 at 1:34 am #

    I wold like to congraduate the team of researchers led by the Yale School of Public Health on their discovery.

    This newfound knowledge will be of great assistance to other scientists that seek to find a cure for Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiens, the two forms of sleeping sickness. It will enable them to create new drugs that do not have the amout of side effects and that is not as toxic as the drugs currently avialable. These drugs are also difficult to administrate. Since most of the people that gets infected with Human African trypanosomiasis come from rural areas, it is difficult to see to it that they receive the correct medical treatment. It can also provide people with beter lifestyles, since it can result in the erradication of this disease not only from humans but also from livestock.

    I think it is wonderful that there are scientists that are so dedicated to discovering new information that can help us overcome diseases. It makes me proud to be associated with science.

  2. nempheni s 14038308 April 29, 2014 at 12:20 am #

    i think if the genome of the fly is finaly traced it wont be that difficult to control this disease since it produces few offspring it will be less difficult to deal with it….the only problem would be the cost of the drug but we can find a way somehow to raise the money from other countries and donate it to help.

  3. R Sivhugwana 14068100 April 28, 2014 at 3:53 pm #

    Yes the disease can be eradicated if people who are already infected by the disease are given the drug for treatment, and if people are given an anti-biotic of that kind of drug,this will make the body to produce antibodies.Then if the protozoan(pathogen) is injected into that body,the body will recognize the protozoan that and prevent it from multiplying.

    But as you have said(Travis) this will be expensive.

  4. Travis Kersten (14070953) April 26, 2014 at 6:04 am #

    I found this article particularly interesting as I live in Zimbabwe, a country where sleeping sickness is unfortunately very common. The disease especially effects the very remote area of the Zambezi Valley. This can heavily effect the tourism industry that relays heavily on income from varies fishing camps and lodges along the Zambezi and shores of Lake Kariba. An effective way of combating sleeping sickness would benefit the industry and economy as well as improving the lives of the thousands of people living in this defined area.

    However, I a few rather critical issues come into play. The most obvious one in my mind is the availability and cost of the drug. The majority of people who live in the Zambezi valley live in extremely remote villages, hundreds of kilometers from the nearest city or even tarred road. These people also live a very basic lifestyle and rely on their own livestock, crops and the days catch for a daily meal. There is no ways they would even be able to afford the “new and improved” drugs if they cost a dollar. So the obvious answer to that would be to have the government supply the medicine. However Zimbabwe health care is in pieces and the government is broke. With the global economy struggling as it is, I personally doubt much extra free aid could be provided by the economic superpowers.

    Another issue in my mind would be the fact that animals can act as a reservoir host, harboring the pathogen, without displaying any noticeable effects. A similar situation is noted with plasmodium parasite of malaria. Even if the disease attacked through humans, the fly can still transfer the pathogen from an animal host. Does this make the disease to widespread with such broad sources that it is almost impossible to eradicate?

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