Cytoskeletal structures inEuglena gracilis after triton X-100 extraction and dry cleaving

Summary A three-dimensional network of structural filaments was visible with common electron microscopes in the cytoplasm ofEuglena gracilis green cells extracted with buffers containing the nonionic detergent Triton X-100. A similar filamentous web was detected at the periphery of critical point dried cells cleaved on grids by means of an adhesive tape. SDS-polyacrylamide gel electrophoresis of the detergent-resistent cytoskeleton showed that actin or actin-like proteins of molecular weight in the range of 43–45 K are not among the components having a structural role inEuglena. The significance of these findings was discussed in relation to the capability of the alga to change the cell shape.The study was supported by grants from Consiglio Nazionale delle Ricerche (CNR) and Ministero della Pubblica Istruzione of Italy.