Monoprotiselle

Monoprotiselle is a hypothetical single-celled protist-like organism used in theoretical biology and science education to explore minimal cellular organization and metabolic capabilities. The name combines mono- (one) with protis (protist) and the diminutive suffix -elle, signaling a small, simplified model cell.

In proposed models, monoprotiselle is typically described as a small, flexible cell ranging from about 2 to 20 micrometers. It is usually depicted as lacking a rigid cell wall, with a single nucleus, and possessing essential organelles such as mitochondria. Depending on the scenario, some versions include plastids for photosynthesis, while others assume a strictly heterotrophic metabolism. Locomotion can be achieved by a flagellum, pseudopodia, or other flexible surface structures, reflecting a range of possible motility strategies.

Metabolically, monoprotiselle is treated as a versatile chassis for different lifestyles. It may be modeled as mixotrophic, combining photosynthesis and phagotrophy, or as a purely heterotrophic cell relying on external organic matter. Energy production is commonly described through aerobic respiration, with optional anaerobic pathways in alternative scenarios.

Reproduction is usually depicted as a simple asexual process, such as binary fission, suitable for illustrating genome duplication and division without the complications of sexual cycles. The concept is frequently employed to discuss minimal gene sets, genome reduction, and the ecological constraints on protist life.

Significance and limitations: monoprotiselle serves as a didactic tool to frame questions about the origins of protists, eukaryotic complexity, and synthetic biology. It is not an observed organism and does not represent a confirmed taxon; rather, it provides a framework for thought experiments and teaching about cellular minimalism.

See also: protocell, protist, minimal genome, synthetic biology, model organism.