A lumenal interrupted helix in human sperm tail microtubules

作者：Zabeo Davide; Heumann John M; Schwartz Cindi L; Suzuki Shinjo Azusa; Morgan Garry; Widlund Per O; Hoog Johanna L^*

来源：Scientific Reports, 2018, 8(1): 2727.

DOI：10.1038/s41598-018-21165-8

Eukaryotic flagella are complex cellular extensions involved in many human diseases gathered under the term ciliopathies. Currently, detailed insights on flagellar structure come mostly from studies on protists. Here, cryo-electron tomography (cryo-ET) was performed on intact human spermatozoon tails and showed a variable number of microtubules in the singlet region (inside the end-piece). Inside the microtubule plus end, a novel left-handed interrupted helix which extends several micrometers was discovered. This structure was named Tail Axoneme Intra-Lumenal Spiral (TAILS) and binds directly to 11 protofilaments on the internal microtubule wall, in a coaxial fashion with the surrounding microtubule lattice. It leaves a gap over the microtubule seam, which was directly visualized in both singlet and doublet microtubules. We speculate that TAILS may stabilize microtubules, enable rapid swimming or play a role in controlling the swimming direction of spermatozoa.

• 出版日期2018-2-9