part of part of outer dense fiber A supramolecular fiber found in the flagella of mammalian sperm that surrounds the nine microtubule doublets. These dense fibers are stiff and noncontractile. In human, they consist of about 10 major and at least 15 minor proteins, where all major proteins are ODF1, ODF2 or ODF2-related proteins. outer dense fibre cellular_component GO:0001520 sperm flagellum polymeric cytoskeletal fiber