Fig. 5: Telomere-led dynamics of synapsis formation and HEI10 loading.

a, Telomeres cluster in a bouquet on one side of the cell, from where ZYP1 is elongating as the SC is being assembled. ASY1 represents unpaired chromosomes not yet reached by ZYP1. The behaviour of ASY1 + ZYP1 + telomeres was consistent in all immuno-FISH cells (n = 8) in three independent experiments. b, As ZYP1 lines elongate from the bouquet, HEI10 is quickly loaded onto synapsed chromosomes, whereas some telomeres localize to the nucleolus and lack the ZYP1 and HEI10 signals. c, Detail of early synapsis initiation and intensity profile of HEI10, ZYP1 and telomere: as soon as the SC (ZYP1) is assembled from telomeres, HEI10 is loaded and shows a high co-localization profile with ZYP1. a.u., arbitrary units. d, In late pachytene, ZYP1 occupies the whole chromosomal length, HEI10 signals become more dot-like and telomeres remain clustered in the bouquet, whereas few telomeres remain at the nucleolus. The behaviour of HEI10 + ZYP1 + telomeres was consistent in all immuno-FISH cells (n = 44) in three independent experiments. Telomeres at the bouquet (white arrow) and at the nucleolus (white arrowhead) are shown. Scale bar, 5 µm.