Western blot of proteins ZmSUN3 and ZmSUN4. (A) Two peptide antibodies were made against synthetic peptides within (zms3gsp1a) and just after (zms3gsp2) the SUN-domain of the maize ZmSUN3 protein. The corresponding regions in ZmSUN3 and ZmSUN4 are aligned, and asterisks indicate divergent residues in ZmSUN4. (B) Western-blot detection (top panel) of ZmSUN3 and ZmSUN4 in various plant tissues. Protein was loaded on an equal-fresh-weight basis for leaf, root, silk, husk, earshoot, embryo, meiosis-stage tassel, and postmeiotic tassel, resulting in the detection of a single band of ~72 kDa. (C) Immunoblot showing the effect of increased sample boiling time on bands detected. Protein from meiosis-stage anthers appeared as a single band at ~70 kDa (arrow) after the protein was boiled in SDS for 10 min or more.