hostdependent

Hostdependent, or host-dependent, is an adjective used to describe entities that require a host organism, cell, or system to function, reproduce, or be maintained. In biology, host dependence commonly refers to obligate parasites that cannot complete their life cycle outside a suitable host, or to host range that restricts infection to certain species or tissues. For viruses, host dependence means reliance on host cellular machinery for replication and translation; viruses cannot replicate outside living cells. Some intracellular bacteria exhibit extreme host dependence, evolving reduced genomes tied to host metabolism. In parasitology and mycology, many parasites or parasitic fungi are described as host-dependent because infection and growth rely on host tissues. Host dependence can also reflect tissue specificity, such as parasites that inhabit only certain organs or cell types.

In laboratory contexts, host-dependent cell culture describes cell lines or tissues that require signals from a feeder layer or host-derived components to proliferate or maintain properties such as pluripotency. Examples include certain stem cell culture systems that rely on feeder cells from animals or other sources to sustain growth.

In computing and software, host-dependent describes programs that rely on features, libraries, or interfaces provided by the host operating system or hardware. Such software may require a specific environment and lack portability to other hosts. By contrast, host-independent tools are designed to operate across hosts with minimal or no host-specific dependencies.

See also: host range, host specificity, obligate parasite, axenic culture.