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bioRxiv · 10.1101/562777

Axonemal doublet microtubules can split into two complete singlets in human sperm flagellum tips

Zabeo, D.·Croft, J. T.·Hoog, J. L.
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Abstract

Motile flagella are crucial for human fertility and embryonic development. The distal tip of the flagellum is where growth and intra-flagellar transport are coordinated. In most, but not all, model organisms the distal tip includes a "singlet region", where axonemal doublet microtubules terminate and only complete A-tubules extend as singlet microtubules to the tip. How a human flagellar tip is structured is unknown. Here, the flagellar tip structure of human spermatozoa was investigated by cryo-electron tomography, revealing the formation of two complete singlet microtubules from both the A-tubule and B-tubule of doublet microtubules. This different tip arrangement in human spermatozoa shows the need to investigate human flagella directly in order to understand their role in our health and disease.

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Zabeo, D., Croft, J. T., Hoog, J. L.. 2019-02-27. Axonemal doublet microtubules can split into two complete singlets in human sperm flagellum tips. https://doi.org/10.1101/562777

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