Relationship between DSB-2 and paralog DSB-1.

<p>(A) Immunofluorescence image of a WT hermaphrodite gonad (from distal tip to end of pachytene), stained with DAPI and antibodies that recognize DSB-2 and DSB-1. DSB-2 and DSB-1 are detected in a highly correlated subset of germline nuclei (within a region spanning from meiotic prophase onset through mid-pachytene), although the relative intensities of the DSB-2 and DSB-1 signals vary during prophase progression (see text). Inset: close-up of the field of early pachytene nuclei outlined in (A) showing that although DSB-1 and DSB-2 are present in the same nuclei, the DSB-1 and DSB-2 signals on chromatin sometimes overlap but mostly do not match each other. Scale bar, 15 µm. (B, C) DSB-1 immunolocalization in the <i>dsb-2(me96)</i> mutant. Zoomed out images show that DSB-1 staining is fairly similar to wild-type control in a 12 h post-L4 <i>dsb-2</i> mutant gonad (C), but DSB-1 staining is reduced (relative to wild-type) in the pachytene region of a 48 h post-L4 <i>dsb-2</i> mutant gonad (B). Insets in C show fields of pachytene nuclei illustrating that RAD-51 foci are already reduced in the <i>dsb-2</i> mutant at 12 h post L4. Scale bars, 15 µm.