Figure 8.

Mildly spread nuclei from testicular suspensions of the rat (Rattus norvegicus) immunostained with anti-hRap1 Abs (Cy3; red) and anti-SCP3 Abs (FITC, green). DNA is shown in blue (DAPI). (a) Premeiotic nucleus with numerous mRap1 signal spots. SC proteins are absent. (b) Mildly spread leptotene/early zygotene nucleus. Numerous thin axial cores are seen with synapsis in progress between two chromosome ends (thick green signal stretch) near the bouquet basis. The latter contains numerous closely spaced chromosome ends, capped with strong mRap1 signals. (c) Mildly spread late pachytene nucleus with distinct mRap1 signals at SC ends. Some SCs extend beyond the focal plane, which is at the top of this nucleus. (d) Mildly spread pachytene nucleus with strong mRap1 signals at SC ends. The closely spaced ends of the backfolded cores of the XY bivalent exhibit distinct mRap1 signals (arrowhead). Top of nucleus shown. Bar in c: 10 μm.