Motile spores facilitate plant infection. Phytophthora pathogens produce motile biflagellate zoospores that can target and swim to suitable infection sites on potential host plants. We have shown that tubular hairs (called mastigonemes) on the anterior flagellum are responsible for forward movement of the zoospores (Cahill et al. 1996). In a collaborative project with Professor Toshinobu Suzaki at Kobe University in Japan, we have cloned a gene encoding the protein that makes up the shaft of the mastigoneme (Blackman et al. 2010). We are currently investigating the identity of other mastigonemal proteins and determining their distribution and function.