Endojens

Endojens is a term used in speculative fiction and some fan communities to describe a class of endosymbiotic organisms that reside inside the cells of a host organism. The term is not recognized in mainstream biology. It blends the prefix endo- (inside) with gens, a root associated with origin or production, to indicate inside-origin lifeforms.

In fictional treatments, endojens are typically depicted as microscopic entities that establish long-term intracellular associations with their hosts. They may be mutualistic, providing metabolic capabilities, regulatory control, or enhanced resilience, or parasitic, competing for resources and altering host physiology. Some narratives portray endojens as genetically integrated with host cells, sharing signaling networks or even aspects of the host genome.

Biology in fiction: In worldbuilding, endojens are described as capable of communication with the host via chemical signals, electrical changes, or light emission. Their life cycle is closely tied to the host's cell division, and they can be transmitted through reproduction, infection, or occasional horizontal transfer in some settings.

Reception and themes: The concept is used to explore host–microbe relationships, the nature of autonomy, and the ethics of genome editing and synthetic biology. It also serves as a vehicle for discussing symbiosis, coevolution, and the boundary between organism and genome.

See also: Endosymbiosis, Microbiome, Endogenous genome, Synthetic biology.

References: The term appears in non-scientific sources and is primarily used for worldbuilding and fiction rather than biology.