Fig. 2. AFD1 localizes to the axial and lateral elements. (A) Localization of AFD1 in a wild-type nucleus stained with DAPI (red) and anti-AFD1 antibody (green) at zygotene, showing an AFD1 signal on both synapsed and unsynapsed chromosome regions. Arrowheads indicate unsynapsed regions. The three panels on the right are magnifications of one region. Individual channels are shown in black and white for clarity. (B,C) Localization of AFD1 and ASY1/HOP1 in wild-type nuclei stained with DAPI (red), anti-AFD1 (green), and anti-ASY1/HOP1 antibodies (blue). Individual channels are shown in black and white for clarity. A projection view of a zygotene nucleus (4% paraformaldehyde fixation) is shown in B. AFD1 and ASY1/HOP1 signals are equally bright on unsynapsed chromosome regions. The ASY1/HOP1 signal is much dimmer where chromosomes are synapsed (arrow). (C) A projection view of a 0.4-µm section of the pachytene nucleus (2% paraformaldehyde fixation). AFD1 and ASY1/HOP1 colocalize and occur in between synapsed homologous chromosomes as two strands, marking the lateral elements. This pattern of immunostaining resembles silver-nitrate staining of lateral elements in SCs. Bars, 5 µm.