Mutant/mutation
The mutant lacks expression of kinesin-8B and expresses GFP under control of the constitutive ef1a promoter

Protein (function)
Proteomic analysis has revealed many potential regulators of axoneme assembly present in male gametes, including members of the kinesin superfamily. Kinesins are molecular motor proteins that have essential roles in intracellular transport, cell division, and motility. Some kinesin families are known to contribute to the ciliary structure and function, either by transporting ciliary components along axonemal  microtubules (MTs) by IFT such as kinesin-2s, or by destabilizing MTs, such as kinesin-9 and kinesin-13. Kinesin-8s are conserved from protozoa to mammals, and can be subclassified as kinesin-8A, -8B and -8X. In general, kinesin-8s are multitasking motors, able to move along MTs, cross-link and slide MTs, and influence MT dynamics at their ends.  Kinesin-8As are best characterised as regulators of spindle length and chromosome positioning during metaphase, whereas the mammalian kinesin-8B (Kif19) has a role in ciliary length control. The Plasmodium genome encodes two kinesin-8s (kinesin-8X and kinesin-8B), along with six or seven other kinesin proteins. Kinesin-8X is conserved across the Apicomplexa, whereas kinesin-8B is restricted to certain genera such as Toxoplasma, Eimeria, and Plasmodium that have flagellated gametes. 

Phenotype
Normal numbers of male/female gametocytes are formed. No male gamete formation (exflagellation). No ookinete and oocyst formation.

Additional information
Evidence is presented for the following:
- Kinesin-8B is not required for DNA replication in activated male gametocytes, but its deletion impairs male exflagellation
- Activated Δkinesin-8B gametocytes lack the 9+2 microtubules (MTs) axoneme architecture. Ddeletion of the kinesin-8B gene did not appear to affect the initiation, growth, or density of single and doublet MTs but completely prevented their organisation into 9+2 axonemes. In addition, there was a reduction in the number of basal bodies and, more markedly, in their association with the nuclear poles. This defect ultimately prevented exflagellation and the formation of viable male gametes.
- Spatiotemporal profiles of kinesin-8B and the kinetochore protein Ndc80 show that kinesin-8B is absent from the mitotic spindle. 
- Kinesin-8B was localised on cytoplasmic MTs rather than on spindle MTs during male gamete formation
- Kinesin-8B associates dynamically with basal bodies and growing axonemes 

Other mutants