When the tail wags the dog

African trypanosomiasis

Trypanosomiasis remains one of the most serious constraints to economic development in sub-Saharan Africa and, as a consequence, related research has been subject to strong social and political as well as scientific influences. The epidemics of sleeping sickness that occurred at the turn of the 20th Century focussed research efforts on what became known as 'the colonial disease'. This focus is thought to have produced 'vertical' health services aimed at this one disease, while neglecting other important health issues. Given the scale of these epidemics, and the fact that the disease is fatal if left untreated, it is unsurprising that sleeping sickness dominated colonial medicine. Indeed, recent evidence indicates that, if anything, the colonial authorities greatly under-estimated the mortality attributable to sleeping sickness. Differences in approach to disease control between Francophone and Anglophone Africa, which in the past have been considered ideological, on examination prove to be logical, reflecting the underlying epidemiological divergence of East and West Africa. These epidemiological differences are ancient in origin, pre-dating the colonial period, and continue to the present day. Recent research has produced control solutions, for the African trypanosomiases of humans and livestock, that are effective, affordable and sustainable by small-holder farmers. Whether these simple solutions are allowed to fulfil their promise and become fully integrated into agricultural practice remains to be seen. After more than 100 years of effort, trypanosomiasis control remains a controversial topic, subject to the tides of fashion and politics.

The emerging complexity of the vertebrate cilium: new functional roles for an ancient organelle

Cilia and flagella are found on the surface of a strikingly diverse range of cell types. These intriguing organelles, with their unique and highly adapted protein transport machinery, have been studied extensively in the context of cellular locomotion, sexual reproduction, or fluid propulsion. However, recent studies are beginning to show that in vertebrates particularly, cilia have been recruited to perform additional developmental and homeostatic roles. Here, we review advances in deciphering the functional components of cilia, and we explore emerging trends that implicate ciliary proteins in signal transduction and morphogenetic pathways.