Phenotype Image Detail

Image

Caption

Impaired development of the connecting piece and the flagellum in Spata6^{tm1a(KOMP)Wtsi}/Spata6^{tm1a(KOMP)Wtsi} (KO) spermatids revealed by transmission electron microscopy (TEM) analyses. (A) Longitudinal section of a wild-type (WT) step 15 elongated spermatid. The connecting piece consists of the well-defined segmented columns (Sc) and the capitulum (Cp), and the capitulum is attached to the basal plate at the implantation fossa (If). Mitochondria (Mi) are well aligned along the outer dense fibers (ODFs - Od) in the mid-piece of the flagellum, and the redundant nuclear envelope (Rn) is present. (Scale bar: 1 um.) (B) Longitudinal section of a KO step 15 elongated spermatid. Segmented columns and capitulum are completely absent, although the basal plate (Bp) can be seen. There is a complete lack of mitochondrial sheath along the ODFs, in all cases accompanied by misplacement of the annulus (An). (Scale bar: 1 um.) (C) Longitudinal section of a mutant step 16 elongated spermatid. Although the proximal centriole (Pc) is present, the segmented columns, capitulum, and mitochondrial sheath are completely lacking, and the annulus is misplaced. (Scale bar: 1 um.) (D) Longitudinal section of a mutant step 15 elongated spermatid. There is no sign of segmented column formation, although a capitulum-like structure can be seen. Moreover, the developing flagellum is misaligned with the developing nucleus (Nu). (Scale bar: 0.5 um.) (E) Longitudinal section of a mutant step 16 elongated spermatid. The segmented columns appear to be partial, and there is no obvious capitulum, although the half-baked segmented columns seem to be attached to the basal plate at the implantation fossa. Again, the mitochondrial sheath is completely lacking, and the annulus is misplaced. (Scale bar: 1 um.) (F-I) Longitudinal sections and cross-sections of step 16 spermatids in mutant testes showing a lack of formation of the mitochondrial sheath (Mt) and misplacement of the annulus (F and G) compared with WT step 16 spermatids (H and I). [Scale bars: 2 um in longitudinal sections (F and H) and 1 um in cross-sections (G and I).] (J) Cross-sections showing the ultrastructure of the mid-piece and the end piece of WT and mutant spermatozoa. Note that the mid-piece of KO spermatozoa exhibits structural defects, including malformed (Upper Middle) or a complete lack of (Upper Right) mitochondrial sheath, partially formed ODFs, and the axonemal microtubules (Ax). In the end piece, WT flagellum consists of fibrous sheath and the typical "9 + 2" arrangement of axonemal microtubules, whereas the KO flagellum contains an atypical "7 + 2" or "8 + 2" composition of axonemal microtubules. (Scale bar: 100 nm.)

Copyright

This image is from Yuan S, Proc Natl Acad Sci U S A 2015 Feb 3;112(5):E430-9. Copyright 2015 National Academy of Sciences, U.S.A. J:217662

Associated Alleles

Symbol	Name
Spata6^tm1a(KOMP)Wtsi	spermatogenesis associated 6; targeted mutation 1a, Wellcome Trust Sanger Institute
Spata6^tm1a(KOMP)Wtsi	spermatogenesis associated 6; targeted mutation 1a, Wellcome Trust Sanger Institute

Associated Genotypes

Allelic Composition	Genetic Background
Spata6^tm1a(KOMP)Wtsi/Spata6^tm1a(KOMP)Wtsi	B6J.B6N-Spata6^tm1a(KOMP)Wtsi