Evidence for asymmetric cell fate and hypoxia induced differentiation in the facultative pathogen protist Colpoda cucullus

Vladimir F Niculescu

doi:10.7243/2052-6180-2-3

Abstract

Accumulating evidence shows that the evolutionary origin of the asymmetric cell fate and stemness begin in the last eukaryotic ancestor (LECA). The mechanisms of asymmetric division and stemness are conserved in descendants and pathogen protists as Entamoeba invadens and Giardia lamblia. It is to be expected that mechanisms for asymmetric cell fate are also conserved in free-living protists and occasionally facultative pathogens. For a better understanding of the ancestral mechanisms involved and their evolution in the protists, we looked for similar mechanisms of cell cycle progression, growth and differentiation in the facultative pathogen protists Colpoda cucullus. We compare what is known about Colpoda cucullus to our findings in E. invadens.

Highlights

In recent papers [1,2] and comments posted at ResearchGate and Academia.edu it was shown that the evolutionary origin of the asymmetric cell fate and stemness begin in the last eukaryotic common ancestor (LECA)
The results suggest that signaling mechanisms for pino- and phagocytosis are retained in mitotically repressed trophozoites, and neither non nutrient media nor Ca2+ ions are the true encystment inducers, capable to convert vegetative cells into ITD cysts (ITD, induced terminal differentiation)
It could be that the true inducer is a shift in hypoxia, similar to the hypoxic/hypoosmotic pressure in oxygen consuming bacteria (OCB) sediments which shift E. invadens to ITD

Summary

Introduction

In recent papers [1,2] and comments posted at ResearchGate and Academia.edu (see www.researchgate.net/profile/ Vladimir_Niculescu/publications and http://uni-tzuebingen. academia.edu/VladimirNiculescu/Papers) it was shown that the evolutionary origin of the asymmetric cell fate and stemness begin in the last eukaryotic common ancestor (LECA). In recent papers [1,2] and comments posted at ResearchGate and Academia.edu Academia.edu/VladimirNiculescu/Papers) it was shown that the evolutionary origin of the asymmetric cell fate and stemness begin in the last eukaryotic common ancestor (LECA). Mechanisms of cell differentiation similar to those of E. invadens were probably conserved in many protists that likely have hidden stem cell lineages in their life cycle. Encystment occurs as terminal differentiation step in prominent commensals and pathogens such as Entamoeba, Naegleria, Acanthamoeba, Iodamoeba, Giardia, Leishmania and Balantidium and in many freeliving protists In the present paper we compare what is known about Colpoda cucullus cell differentiation to our findings in E. invadens [1,2] and Giardia The multilined cell system of Giardia lamblia in the light of the modern protist stem cell biology)

Methods

Results

Conclusion