Phenotype Image Detail

Image

Caption

A-D: Scanning electron micrographs of Spem1^tm1Wyan/Spem1^tm1Wyan (B-D) and wild type mice (A) epididymal sperm. (Scale bars: 10 m; Inset, 2 m.) Insets are the higher magnification images of the head and neck region of the sperm. E-H: Transmission electron microscopy analyses of homozygous mutant mouse sperm head and neck region. (Scale bars: 1 m.) E: Cross section of the cytoplasmic droplet (CD) of wild type spermatozoon. 1, Middle piece of the tail composed of mitochondrial sheath, outer dense fibers, and axoneme with typical "9 + 2" microtubule structure (9 pairs of peripheral and two central microtubules); 2, vacuoles within the droplet; 3, homogeneous-looking contents within the droplet; 4, outer membrane of the droplet. F: A section through the bent head and neck region of a mutant mouse spermatozoon. 1, Vault of proximal centriole; 2, nucleus; 3, neck of the sperm composed of a sheath of two longitudinally aligned mitochondria, outer dense fibers, and axoneme with typical "9 + 2" microtubules; 4, outer membrane; 5, middle piece of the tail consisting of the sheath of circumscribing mitochondria and axoneme; 6, small membranous vacuoles with interconnections at areas of folding. (G) A section of a mutant mouse sperm head bent at the neck and wrapped by the middle piece of the tail. The head, neck, and the proximal portion of the middle piece of the tail are surrounded by membranous structures resembling cytoplasmic remnants. 1, Numerous small inter-connected membranous vacuoles; 2, single, large myelin-like vacuoles, which are likely to result from fusion and expansion of those small membranous vacuoles as seen in 1; 3, outer membrane; 4, sperm neck; 5, connecting piece; 6, acrosome. H: A mutant mouse spermatozoon with the head bent at the neck and wrapped around by the middle piece of the tail. The middle piece and head are held together by cytoplasmic remnants with similar structures as seen in F and G. 1, Interspaces between the basal plate and connecting piece (absent here); 2, basal plate; 3, nucleus; 4, outer membrane of the cytoplasmic remnants; 5, large membranous vacuoles; 6, a large myelin-like vacuole; 7, middle pieces of the tail wrapping around the head.

Copyright

This image is from Zheng H, Proc Natl Acad Sci U S A 2007 Apr 17;104(16):6852-7. Copyright 2007 National Academy of Sciences, U.S.A. J:120937

Associated Alleles

Symbol	Name
Spem1^tm1Wyan	spermatid maturation 1; targeted mutation 1, Wei Yan

Associated Genotypes

Allelic Composition	Genetic Background
Spem1^tm1Wyan/Spem1^tm1Wyan	involves: 129S1/Sv * 129X1/SvJ * C57BL/6J