Canals connecting sister cystocytes in the Drosophila egg chamber. The rim of each canal is formed by a partially closed contractile ring (q.v.). The canal system is initially plugged by a polyfusome (q.v.). Once this dissolves, the ring canals allow a stream of cytoplasm to flow from the nurse cells (q.v.) to the oocyte. As each ring matures, it develops a coating of actin filaments and increases in diameter and thickness. During the growth of the egg chamber, proteins encoded first by the gene hts and later by kel serve to organize the actin filaments by cross-linking them in various ways. This process requires phosphorylation reactions catalyzed by Src protein tyrosine kinases. See cystocyte divisions, hu-li tai shao (hts), kelch (kel), and Src.
Subjects: Genetics and Genomics.