W. Brockley Paterson

The polar ring complex in ookinetes of Leucocytozoon simondi (Apicomplexa: Haemosporina) and evidence for a conoid in haemosporidian ookinetes

Ookinetes of Leucocytozoon simondi have a Polar Ring Complex (PRC) which is composed of a stout electron-lucent polar ring with about 34 posteriorly extending tines. The latter are subtended by about 76 subpellicular microtubules. A broad collar of electron-dense material is associated with the cytoplasmic surface of the inner double membrane complex of the pellicle. Additional particulate material of varying density occupies the space between tines and the dense material associated with the pellicle. A conoid and two preconoidal rings are present. We conclude that a PRC and a typical apicomplexan conoid, although often unrecognized, occur in ookinetes of all the haemosporidians examined thusfar.