The paraflagellar rod of kinetoplastida: Solved and unsolved questions

The flagellum of almost every member of the Kinetoplastida contains, next to its canonical 'nine-plus-two' axoneme structure, a unique, complex and highly organized lattice-like structure called the paraflagellar rod or paraxial rod. Here, Philippe Bastin, Keith Matthews and Keith Gull summarize the latest findings on its structure, the nature of its protein components and their corresponding genes. They also consider the possible functions of this intriguing organelle.