Tpx-1 is a component of the outer dense fibers and acrosome of rat spermatozoa
M K O’Bryan 1, K Sebire, A Meinhardt, K Edgar, H H Keah, M T Hearn, D M De Kretser

Formerly we reported the cloning of part of the cysteine-wealthy secretory protein family, tpx-1, from the testis expression library utilizing an outer dense fiber (ODF)-specific antiserum. Using immunohistochemical and immunoelectron microscopic techniques and Western blotting of purified sperm tail components, we’ve determined that tpx-1 exists as 25 and 27 kDa proteins in 2 aspects of rat spermatid: the ODFs and also the acrosome. Tpx-1 mRNA is first expressed within the late pachytene spermatocytes, but producing these tpx-1 proteins is translationally delayed for 4-five days prior to being integrated into the developing sperm acrosome, all around the elongating and condensing spermatid nucleus. Concurrent with sperm mind formation, tpx-1 protein was integrated into the developing sperm tail, and particularly the ODFs. The tpx-1 protein was seen within structures resembling granulated physiques within the cytoplasmic lobe of elongating spermatids and it was incorporated subsequently in to the growing tail inside a manner in line with ODF development. Additionally, tpx-1 protein was localized in the ultrastructural degree of the connecting bit of the neck and longitudinal posts from the ” floating ” fibrous sheath, suggesting common protein components during these cytoskeletal structures. As a result, tpx-1 might have functional significance within the processes of sperm mind development and tail function.TPX-0046