The versatile stellate cell – More than just a space-filler

Most epithelia contain multiple cell types that interact to perform the roles required of the tissue. In insect epithelia, the apical plasma membrane V-ATPase dominates ion-transport models, and (as in vertebrates) is usually found in specialized intercalated cell types or regions. The Malpighian tubules of several insect Orders contain not just a mitochondrion-rich principal cell expressing high levels of V-ATPase, but a smaller, intercalated “type II”, “secondary” or “stellate” cell. Recent data show that this cell type plays a key role in control of chloride and water flux across the tissue, but also may play other, still unsuspected dynamic roles.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Malpighian tubules perform key excretory functions in most insects. ►Several insect Orders have stellate, as well as larger principal, cells. ►In Diptera, stellate cells play a key role in regulating chloride and water flux. ►Recent data imply further functional richness and dynamic roles for these cells. ► It is not known how these roles are performed in tubules that lack stellate cells.