Fig. 7. Synapsis between the homologous chromosomes is defective in the Hsf2^–/– mice. (A) Immunofluorescence labeling with anti-SCP3 antibody (Cy3 channel, red) and Crest anti-centromere sera (FITC channel, green). A part of a seminiferous tubule in developmental stage VIII (Clermont, 1972), with middle pachytene spermatocytes (mp), round spermatids (rs) and elongated spermatids (es). Loop-like configurations are present between one or more pairs of homologous chromosomes (arrow in the inset A). (B) An SC with one loop-like structure near the centromere terminus of a chromosome pair (arrow) (Z-level section). (C) Separation of the lateral elements at the centromere region (arrowheads in the inset C; stack of five Z-level sections from a confocal microscope series). Merge of anti-SCP3 (red) and Crest (green) in images (B) and (C). Bars = 10 µm.