transduction

Transduction is a term used in biology and related fields to describe the conversion of one form of energy or information into another. In physiology and neuroscience, it refers to the process by which a sensory receptor converts a physical or chemical stimulus into an electrical signal that the nervous system can interpret. In genetics and microbiology, transduction denotes the transfer of genetic material from one organism to another, typically mediated by a virus such as a bacteriophage.

In signal transduction, cells respond to external cues through cascades of molecular interactions that convert an extracellular signal into a functional cellular response. Receptors detect ligands and initiate intracellular signaling involving second messengers, kinases, and transcription factors. Pathways vary in architecture—common motifs include G protein-coupled receptors and receptor tyrosine kinases—and are regulated by feedback and cross-talk to produce appropriate, context-dependent outcomes.

Sensory transduction refers to converting environmental stimuli into neural signals. Phototransduction in the retina changes photoreceptor membrane potential in response to light; olfactory and gustatory transduction convert chemical compounds into receptor potentials; mechanotransduction converts physical forces into electrical signals in skin, inner ear hair cells, and other sensors.

Genetic transduction involves bacteriophage-mediated transfer of DNA. Generalized transduction packages random host DNA into phage particles, while specialized transduction transfers specific adjacent genes. Transduction is distinct from transformation (uptake of naked DNA) and conjugation (direct cell-to-cell transfer). In biotechnology and gene therapy, viral transduction is used to deliver genes into cells, with attention to safety, specificity, and efficiency.