Coelomocyte spectrin

Abstract
We have investigated the presence and localization of an α‐spectrinlike protein and its potential role in the morphological transformation of sea urchin coelomocytes. In immunofluorescence images there is a diffuse fluorescence throughout the petaloid cytoplasm, indicating a random distribution of the spectrinlike protein prior to the transformation. As these cells form filopodia, there is a coincident appearance of a spectrinlike protein, as seen in fluorescent images, at the site of filopodial initiation. As the filopodia continue to form and lengthen, the spectrin localization parallels their development. There is a single polypeptide observed on sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) gels of whole coelomocyte lysates that cross‐reacts with the anti‐α‐spectrin immunogen and comigrates with it at 240 kilodaltons.