Phenotype Image Detail

Image

Caption

Structure of spermatids (A) and epididymal sperm (B-E) from Krt19^tm1Alki/Krt19^tm1Alki (K9^neo/neo) mutants. The looping middle piece of the developing tail can already be seen in maturing spermatids (A). Four typical abnormalities can be seen; a hook-shaped middle piece (B), U-shaped tails formed by the close apposition of the middle piece to the principal piece and enclosing residual cytoplasm (C), "bobtail" thick sperm tail (D), and a high incidence of conjoined sperm with independent heads (E; labeled H1,H2) and middle piece of the tail (arrowheads) fused with the principal piece. F: Electron microscopy of a "U-shaped" epididymal sperm of the heterozygous (K9^+/neo) mutant displaying a vesicle-containing (arrowheads) residual cytoplasm at the end of the mitochondrial-containing middle piece (Mitoch). The caudal margin of the residual cytoplasm usually does not extend beyond the annulus (the demarcation between the middle and principal piece of the sperm tail). G: Cross-section of epididymal sperm of the homozygous mutant. The dashed circles denote cross-sectioned tail middle pieces within a common cytoplasm displaying vesicles (arrowheads). This arrangement corresponds to the plasma membrane fusion of a hook-shaped sperm tails (see panel B). The dashed bracket indicates the eccentric position of a sperm tail surrounded by a wide cytoplasmic region containing vesicles (arrowheads). This pattern may represent a cross section of a "bobtail" sperm (see panel D). Panels H, I demonstrate the accumulation of myosin Va immunoreactivity (arrow) in the residual cytoplasm (similar to that shown in F). The arrowhead points to the lack of immunoreactivity beyond the residual cytoplasm.

Copyright

This image is from Rivkin E, Mol Reprod Dev 2005 Oct;72(2):259-71, and is displayed with the permission of Wiley-Blackwell, who owns the Copyright. J:125621

Associated Alleles

Symbol	Name
Krt19^tm1Alki	keratin 19; targeted mutation 1, Abraham L Kierszenbaum

Associated Genotypes

Allelic Composition	Genetic Background
Krt19^tm1Alki/Krt19^tm1Alki	involves: 129X1/SvJ * C57BL/6J
Krt19^tm1Alki/Krt19^+	involves: 129X1/SvJ * C57BL/6J