From cell culture to cellular biology in animal-parasitic nematodes: Biotechnological advances.

Animal-parasitic nematodes are pathogens of medical and veterinary importance, yet their cellular biology remains poorly resolved because complex life cycles, host-dependent development and limited access to particular stages constrain investigation. This conceptual review traces nematode cellular biotechnology from efforts to isolate and maintain nematode-derived cells to the definition of cellular identity and its integration with biological function. Early culture studies showed that cells from free-living and parasitic nematodes could be isolated, maintained and sometimes propagated, but their identity was inferred indirectly from morphology, biochemical activity and immunological characteristics. Single-cell and single-nucleus transcriptomics transformed this landscape, with Caenorhabditis elegans providing foundational methods and atlases for resolving cellular diversity, developmental trajectories and tissue organisation. Advances in plant-parasitic nematodes and parasitic trematodes provide methodological insights. In animal-parasitic nematodes, these approaches now include whole-parasite dissociation, nuclei isolation, tissue-specific profiling and spatial transcriptomics. Organoid and co-culture systems provide access to host-parasite interfaces, while functional-genetic platforms enable experimental perturbation. The emerging landscape is heterogeneous: some systems provide cellular or spatial maps, whereas others offer greater tractability through culture, host-derived models or genetic manipulation. No single system yet provides life-cycle-wide cellular coverage, spatially resolved tissue organisation, sustained culture of parasite-derived cells or tissues and reliable functional perturbation. We identify priorities for linking cellular identity to developmental dynamics, anatomical context, culture authentication and experimentally testable function. Collectively, these advances are moving the field from maintaining cells and defining their identity towards understanding and manipulating cellular function, thereby supporting approaches to the treatment and control of animal-parasitic nematode infections.