Cauda epididymal spermatozoa of high percentage XL169 chimaeric males acquire additional defects. In cauda epididymis we noted the presence of many spermatozoa with the bent tails. Panel A shows a spermatozoon with a normal head and a bent tail resulting from the midpieces folding and fusing on itself. Note the absence of several ODF. Panel B shows that the bending can result in fusion of the midpiece (arrowhead) (seen in the majority of cases), as well as fusion of the midpiece and principal piece (arrow). Panel C illustrates that on occasion a fusion as a result of bent tails was observed in spermatozoa from low-medium percentage XL169 chimaeric animals. Magnification is 45,000 ×.
Tarnasky et al. BMC Developmental Biology 2010 10:67 doi:10.1186/1471-213X-10-67