Basal body structure and composition in the apicomplexans Toxoplasma and Plasmodium

Area of Science:

• Cell Biology
• Parasitology
• Structural Biology

Background:

• Apicomplexa, including Plasmodium (malaria) and Toxoplasma (toxoplasmosis), are significant human and animal pathogens.
• While asexual stages of some apicomplexans possess centrioles, male gametes uniquely develop flagella, with poorly characterized basal body structures.
• The origin and precise structure of apicomplexan microgamete basal bodies remain unclear, with limited ultrastructural data available.

Purpose of the Study:

• To investigate the poorly defined basal body structure in apicomplexan male gametes.
• To clarify the relationship between asexual stage centrioles and microgamete basal bodies.
• To explore potential therapeutic targets by understanding apicomplexan basal body biogenesis and structure.

Main Methods:

• Review of existing ultrastructural images of apicomplexan microgametes, particularly Toxoplasma.
• Comparative genomic analysis of apicomplexan genes involved in basal body and flagellar biogenesis.
• Analysis of conserved basal body components (e.g., δ/ε-tubulin, UNIMOD components) in apicomplexan genomes.

Main Results:

• Apicomplexan microgamete basal bodies are distinct from metazoan counterparts and their structure is not well-defined.
• While some apicomplexans have centrioles in asexual stages, their relationship to microgamete basal bodies is unclear.
• Apicomplexan genomes contain genes for typical basal body components but lack others, suggesting unique biogenesis pathways.

Conclusions:

• The unique structure and biogenesis of apicomplexan basal bodies present potential targets for selective therapeutic intervention.
• Inhibiting microgamete motility, driven by these flagellar structures, could disrupt parasite genetic diversity and transmission.
• Further ultrastructural and molecular studies are needed to fully elucidate apicomplexan basal body assembly and function.