Brdu nuclei staining of embryos at different stages. Aphids were submitted to plant/chemical feeding as described in figure 1. A: DAPI (4,6'-diamidino-2-phenylindole) blue fluorescent dye for staining nuclei reveals a germarium, first (1st)and second (2nd)embryo. B: Stained nuclei by DAPI (d) are represented in red. Green nuclei are Brdu (b) staining using an antibody FITC (Sigma Aldrich). We observe rare nuclei under replication. C: An early embryo showing numerous nuclei stained with anti Brdu FITC. We see the partially empty center and the external border enriched in giant nuclei (x) likely from polynucleated cells. D: old embryo before birth. Nuclei are stained with DAPI (red) (d) and the Brdu labelled nuclei (green) (b) are essentially present in legs, antennae and stylet. E: Representation of four types of cell division. We see replication in polynucleated cells (pn), chromosome segregation (cs), compact double nuclei (cdn) and nascent process of replication.