The late pachytene ZW^RPA+ pair has no MLH1 focus.

<p>Oocytes triple stained for SYCP3 (green), RPA (blue) and MLH1 (red). (A) The ZW^RPA+ pair carrying a chain of RPA foci on the Z never has a MLH1 focus (white arrowhead indicates the expected location of the focus); total number of oocytes analysed: 62. (B) The fully synapsed ZW bivalent always carries a MLH1 focus at one end (white arrow); Total number of oocytes analysed: 138. Drawings of the ZW pair to the right of ech panel. ZW pairs were identified using ZW chromosome paints (data not shown). Scale bar = 10 µm.