Skip to main content

Table 1 Morphology of gametocytogenesis

From: Gametocytogenesis : the puberty of Plasmodium falciparum

  Stage I Stage II Stage III Stage IV Stage V
Shape (Light microscopy) [4,16, 18, 159] IA: Indistinguishable from the small round trophozoite IB: Larger round shape, distinguished by granular distribution of pigment in food IIA: elongates within the erythrocyte IIB: D shaped D shaped, slightly distorted erythrocyte Pink/blue distinction of the male/female. Elongated and thin parasite, distorted red cell Male: pigment tends to be scattered Female: pigment more dense Sausage shaped parasite with rounded extremities Male: pigment scattered, pink Female: dense pigment, light violet (see Figure [1])
Ultrastructure [18] -No visible alteration of the erythrocyte plasmalemma ("knobless"), opposite the knobbed asexual infected erythrocyte
-Formation of a subpellicular membrane flattened vesicle and microtubule array
-Sexual dimorphism in nuclear size
-Subpellicular membrane and microtubule complex in expansion (giving the D form) giving an asymmetrical cell
-Nucleus in terminal site or elongated across the long axis of the cell; some spindle observed within it
-Further development of the subpellicular membrane complex distorts cell
-Male nucleus is notably larger(also becoming lobbed) then that of the female, which contains slightly more ribosomes, ER and mitochondria then the male.
-Membrane and microtubule complex now surrounds the gametocyte completely (restoring symmetry)
-Appearance of membrane bound osmophillic bodies
-Obvious sexual dimorphism: mitochondria, ribosomes and osmophillic bodies more numerous in female, a transcription factory is observed; male nucleus is larger
In male kinetochores of each chromosome are attached to an electron dense body, located over a nuclear pore, opposite of which there is a MTOC (cytoplasmic face of the pore)
-Loss of subpellicular microtubules by depolymerisation, the inner membrane remains
-Microgametocyte (male) exhibit a dramatic reduction in ribosomal density, very few mitochondria, with a large nucleus with a kinetochore complex attached to the nuclear envelop
-Numerous mitochondria, ribosomes and osmophillic bodies in the macrogametocyte (female); the nucleus is small with a transcription factory
Time of appearance (days) [159] 0–2 1–4 2–8 6–10 9–23
Point in the cell cycle [160] G1 G1 G0 G0 G0