Researchers have revealed that genetic adaptions of tsetse fly allow it to have such unique biology and transmit disease to both humans and animals.
The tsetse fly spreads the parasitic diseases human African trypanosomiasis, known as sleeping sickness, and Nagana that infect humans and animals respectively.
The team, composed of 146 scientists from 78 research institutes across 18 countries, analysed the genome of the tsetse fly and its 12,000 genes that control protein activity.
The tsetse flies genome is twice as large as fruit fly's. Within the genome are genes responsible for its unusual biology. The reproductive biology of the tsetse fly is particularly unconventional: unlike most insects that lay eggs, it gives birth to live young that have developed to a large size by feeding on specialised glands in the mother.
Researchers found a set of visual and odour proteins that seem to drive the fly's key behavioural responses such as searching for hosts or for mates. They also uncovered the photoreceptor gene rh5, the missing link that explains the tsetse fly's attraction to blue/black colours. This behaviour has already been widely exploited for the development of traps to reduce the spread of disease.
The team found one family of genes, the tsal genes, that are particularly active in the salivary glands of the tsetse fly. This allows the tsetse fly to counteract the responses from the host to stop bloodfeeding.
This finding and several others are explored in more detail in eight research papers that accompany the publication of the tsetse fly genome in Science.