Sejttípust

Sejttípust, or cell type, is a category of cells defined by shared characteristics such as morphology, gene expression, and function. In multicellular organisms, cells differentiate into distinct types during development, and maintain specialized roles. Cell types are often associated with a tissue or organ and can be further divided into subtypes.

Classification is based on origin and function: by lineage (germ layer), by tissue category (epithelial, neuronal, muscle, connective, blood), or by specialized roles. Boundaries between types can be fuzzy, and context matters; cells may have multiple states depending on environment and developmental stage.

Identification methods include histology, cytochemistry, immunohistochemistry, flow cytometry, and modern genomics such as single-cell RNA sequencing and proteomics. Markers, including cell-surface proteins like CD molecules, help define and distinguish different cell types in tissues and cultures.

Studying cell types is central to developmental biology, physiology, and pathology. Changes in cell type composition or in cell states underlie many diseases, and cell-type information guides cancer classification, immunology, and regenerative medicine. Researchers also create cell-type atlases to catalog diversity and to map how cell types relate to function and disease.

In Hungarian literature and scientific use, sejttípus is used similarly to the English term cell type; however, terminology can evolve as new data emerge, and distinctions are made between stable cell types and transient states or transitional phenotypes.