Sex Matters for Microbes Responsible for African Sleeping Sickness

African sleeping sickness can be devastating for those who contract it. Now, though, scientists have observed the microbes responsible for this disease in the act of mating. The findings could help develop better treatments and prevention methods for this particular disease.

African sleeping sickness, also known as African Trypanosomiasis, is caused by microscopic parasites of the species Trypanosoma brucei. Historically, it's been a serious public health problem in some regions of sub-Saharan Africa. While curable with medication, it can be fatal if left untreated.  Symptoms can include fever, rash, swelling of the face and hands, headaches, fatigue, aching muscles and joints, itching skin and swollen lymph nodes. If the illness progresses, weight loss can occur along with daytime sleepiness.

The microbes that cause this disease are actually transferred by tsetse flies. That's why in order to learn a bit more about the disease, the scientists used fluorescent markers in order to see what the microbes were doing inside the tsetse flies. The researchers observed the microbes twirling and gyrating together before joining up into one hybrid cell. This hybrid cell contained colors from each of the individual microbes that were tagged. That's when the researchers realized they had witnessed these microbes in the act of mating.

"It's not only bigger animals that have intricate courtship--but you need a powerful microscope to see this," said Wendy Gibson, one of the researchers, in a news release.

Sex in these microbes matters quite a bit. It allows genes to be swapped between different strains and leads to new combinations of genes. In the case of disease-causing microbes like trypanosome, sex can potentially lead to a lot of harmful genes being combined into one strain. What's interesting is that this study reveals that sex isn't an optional or rare part of this microbe's life cycle; instead, it probably happens every time two different trypanosomes find themselves together in the same tsetse fly.

The findings are published in the journal Current Biology.