Phenotype Image Detail

Image

Caption

Electron microscopy cross-sections of sperm from Cfap44^em1Pfr/Cfap44^em1Pfr (Cfap44-/-) males reveal multiple structural axonemal defects. a) Cross-section of the midpiece of a wild-type (WT) sperm, showing the arrangement of the outer dense fibers (ODFs) around the axoneme. b) Presence of ODFs in midpieces sections of sperm from mutant males. The orientation of ODFs is also defective, leading to an increase of the midpiece diameter. a, b) Same scale bars = 250 nm. d-f) Various structural defects of the axoneme in sperm from mutant males. d) Four doublet of microtubules (DMTs, 4-7) were missing. The central pair is shifted at the periphery (red arrowhead). e) DMTs 5-7 were missing. Note the presence of a third longitudinal column (LC). f) Irregular distribution of the DMTs associated with a rotation of the central pair (straight red line). Scale bars = 196 nm. g) In WT sperm, the fibrous sheath is linked to the 3-central-8 complex by stalks emerging from the longitudinal columns (white arrowheads). h, i) The presence of extra ODFs facing DMTs 3 and 8 (red arrowheads) prevents a normal anchoring of the fibrous sheaths stalks on DMTs 3 and 8. Scale bars = 270 nm. j-n) LCs are not aligned with 3-8 central pair complex (CPC) axis. In contrast to WT, where the 3-central-8 complex is aligned with LC to form almost a straight line (j, red line), LC are misaligned in sperm from mutant males, leading to notable asymmetry of the structure (k, m, red lines). l, n) The presence of a third LC increases asymmetry. Scale bars = 184 nm. One hundred cross-sections in the principal piece region were analyzed for WT and 50 for the mutant.

Copyright

This image is from Coutton C, Nat Commun 2018 Feb 15;9(1):686, and is displayed under the terms of the Creative Commons Attribution 4.0 International License. J:257803

Associated Alleles

Symbol	Name
Cfap44^em1Pfr	cilia and flagella associated protein 44; endonuclease-mediated mutation 1, Pierre F Ray

Associated Genotypes

Allelic Composition	Genetic Background
Cfap44^em1Pfr/Cfap44^em1Pfr	involves: C57BL/6J