Figure 3

Primary spermatocytes of D. melanogaster.(a, b) H4K20me2; (c, d) H4K20me1; (e) H3K9me1. (a, c) Antibody reactions; (b, d, e) merged pictures of DAPI and antibody. (c-e) Show the characteristic patch-like patterns of prominent reactions with X chromosome and autosomes. In the smaller young spermatocytes (Stc(y)) the chromatin is more compact while in the larger nuclei of older stags (Stc(o)) is becomes more diffuse. In (e) two spermatogonia (Stg) are seen which still display some low cytoplasmic label (Cy) while the spermatocytes are not labeled around their nuclei (N). (a, b) display a more uniform label with some prominent patches in older spermatocytes. One of these patches represents the nucleolus.