Tubulation

Tubulation is the process by which organisms or materials form tubes or tubular structures. In biology, tubulation refers to the remodeling of membranes or tissues into elongated cylindrical shapes, often to increase surface area or connect compartments. It occurs at the cellular level, where organelles such as the endoplasmic reticulum, mitochondria, and Golgi apparatus generate tubular extensions. Proteins that bend membranes and cytoskeletal elements that provide force drive tubulation, with regulation during development and in response to stress.

In development and cell biology, tubulation underlies tubulogenesis, the formation of tubular organs and lumens in multicellular organisms. Epithelial cells undergo coordinated shape changes, polarization, and rearrangements to produce continuous tubes such as blood vessels, renal tubules, and glandular ducts. Trafficking of membranes, apical-basal polarity, and branching morphogenesis are common mechanistic themes in tube formation.

In plant biology, tubulation can describe the development of tube-like elements in vascular tissues, as well as certain membrane-based remodeling events within cells. In materials science and nanotechnology, tubulation refers to the creation or transformation of tubular structures such as carbon nanotubes, polymer tubes, and inorganic nanotubes, achieved by self-assembly, templating, or phase transitions.

The term is used across disciplines to denote a shift from planar or particulate organization to tubular geometry. Studied aspects include the physical forces, molecular actors, and cellular rearrangements that stabilize tubes and integrate them into larger tissues or materials. See also tubule, tubulogenesis, and morphogenesis.