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

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 model organisms, but not all, the distal tip includes a 'singlet region', where axonemal doublet microtubules (dMT) terminate and only complete A-tubules extend as singlet microtubules (sMT) 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 a complete sMT from both the A-tubule and B-tubule of dMTs. This different tip arrangement in human spermatozoa shows the need to investigate human flagella directly in order to understand their role in health and disease.

SUBMITTER: Zabeo D

PROVIDER: S-EPMC6594080 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature

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

Zabeo Davide D Croft Jacob T JT Höög Johanna L JL

FEBS letters 20190419 9

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 model organisms, but not all, the distal tip includes a 'singlet region', where axonemal doublet microtubules (dMT) terminate and only complete A-tubules extend as singlet microtubules (sMT) to the tip. How a human flagellar tip is structured is unknown. Here, the flagellar tip structure of human spermatozoa was investig ...[more]

PMID: 30959570

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