Influence de la maintenance d'une souche de Plasmodium berghei Anka sur la gamétogénèse

Clones of P. berghei, isolated after 281 cyclical passages, and after 28 and 35 subsequent mechanical passages were compared with respect to gametocyte production and infectivity for mosquitoes. All the clones obtained after the 281th cyclical passage were capable of sexual reproduction. However, the clones isolated after the 28th mechanical passage exhibit three types of sexual development: 5 clones completed sporogony, 1 clone only produced ookinetes, and 7 clones showed no gametocyte fertilization. From the 11 clones isolated after 35 mechanical passages, only one could produce ookinetes, the others did not show any gametocyte fertilisation. The number of mechanical passages is inversely correlated with the production rate of gametocytes (R = -0.95, P < 0.001) and with the infectivity rate of the gametocytes (R = -0.86, P < 0.01).