Tritrichomonas foetus Cell Division Involves DNA Endoreplication and Multiple Fissions

Area of Science:

• Microbiology
• Parasitology
• Cell Biology

Background:

• Tritrichomonas foetus and Trichomonas vaginalis are extracellular flagellated parasites.
• Previously, their reproduction was assumed to be exclusively by binary fission.

Purpose of the Study:

• To investigate alternative cell division and survival mechanisms in T. foetus and T. vaginalis.
• To characterize novel dormant phenotypes under stress conditions.

Main Methods:

• Culturing T. foetus and T. vaginalis strains under standard and stress conditions (nutritional depletion/deprivation).
• Microscopic observation of cell morphology, multinuclearity, and nuclear content.
• Analysis of DNA content and cell division processes.

Main Results:

• Multinuclearity is regularly observed in both T. foetus and T. vaginalis under standard conditions.
• Nutritional stress induces distinct dormant phenotypes: multinucleated cells (depletion) and large mononucleated polyploid cells (deprivation).
• DNA endoreplication occurs under stress, preceding multiple fission upon restoration of favorable conditions, enabling rapid parasite generation.

Conclusions:

• T. foetus and T. vaginalis exhibit multiple fission, a previously unrecognized reproductive mode under stress.
• Endoreplication is a key strategy for these parasites to increase DNA content under nutritional stress.
• Novel dormant forms (multinucleated/polyploid) exist, potentially impacting parasite transmission and requiring further investigation.