Immunolocalization of ASY1, DMC1, and H3K27me3 in pollen mother cells of wheat cultivar Cadenza during prophase I. (A) Immunolocalization of the axis protein ASY1 (green), combined with fluorescence in situ hybridization (FISH) of the telomeric repeat sequence (TELs, red) from Arabidopsis thaliana at the G2/leptotene transition. ASY1 signal is enriched in distal regions as the telomeres begin to cluster into a “bouquet” arrangement and the axis begins to linearize. (B) Leptotene-stage pollen mother cell immunostained for DMC1 foci (red) and co-immunostained for ASY1 (green), as axis linearization progresses through the nucleus. The zoomed detail of distal regions is from a single Z-frame (mid-nucleus) and shows individual DMC1 foci decorating the axis stained by ASY1. (C) Early-leptotene-stage pollen mother cell showing enrichment of H3K27me3 in distal regions, which are also marked by intense ASY1 immunostaining (yellow arrow). (D) H3K27me3 distal enrichment persists in early zygotene when chromosome axes are fully linear (yellow arrow). 4′,6-diamidino-2-phenylindole (DAPI) marks DNA. Scale bars = 10 µM. For clarity, some images are shown in several color combinations.
