Synapsis and XY body formation in pachytene spermatocytes of B10-T43/+ sterile males and B10 controls. (a) Scheme of pachytene synapsis in the translocation quadrivalent of B10-T43/+ males. Proximal (centromeric) parts of chromosomes 17 and 1716 are most prone to synaptic failure. (b) Synaptonemal complexes were labeled with anti-SCP3 antibody. The arrowheads indicate the axial elements of sex chromosomes; the arrow points to the aberrantly synapsed translocated autosomes. (c) The unsynapsed chromatin was detected by immunostaining with anti-BRCA1 antibody (red). BRCA1 was immunolocalized on the sex chromosomes of sterile and fertile males and within translocated chromosomes in the sterile male. The SCP3 visualized axial elements (green); chromosome painting identified chromosome 17 (light blue). (d) Spread spermatocytes from sterile and fertile males were coimmunostained with anti-SCP3 (green) and anti-gamma H2AX (red) to disclose differences in XY body formation. Painted chromosome 17 is shown in light blue.
