Malaria parasites must sense their environment to regulate gene expression- for instance, to evade immunity or to produce gametocytes at the optimal sex ratio. The underlying molecular mechanisms remain largely unknown, though available evidence points to a strong role for epigenetic regulation. We have established several parasite lines from symptomatic patients, including those with severe anaemia, and are characterising these clinical isolates to understand how sex ratio determination and variant antigen expression are regulated in the gametocytes they produce. We work closely with Prof. Oliver Billker, MIMS, Umeå, Sweden.