Fig. 5. Number and distribution of TNs. (A) A mid-pachytene nucleus with 140 RPA-TN foci (Rhodamine, red, but yellow on a green background) positioned fairly evenly along the SCs (green) (see supplementary material Fig. S4, cell 02). The number of TNs in this nucleus has declined from the original 250+ foci at zygotene. (B) At late pachytene, there remain few TNs – 33 in this nucleus (see supplementary material Fig. S5, cell 09). Uneven loss of TNs leaves an uneven distribution along the SCs and some SCs have no TNs. MLH1 foci (blue) have developed by this stage.