Fig. 1: Galleria mellonella embryos fixed during set points in development and stained with Hoechst 33258 DNA dye.

a–c, In the first 1.25–2.75 h PO, the sperm nuclei (purple circle) can be seen moving toward the ovum nuclei (yellow circle) (a); and nuclei resembling polar bodies gather toward the periphery of the embryo (white arrows) (b). This timeframe appears to cover up to the second mitotic division (c). d,e, From 2.5 h to 5.5 h PO, energids migrate toward the periphery with a bias to the anterior pole (d); and by 4.5–5.5 h PO, the first ones have just reached the periphery (e). Nuclei are dividing synchronously at this point as they share a common cytoplasm. f, All energids have reached the periphery by 6.25 h and are still dividing together. g,h, However, synchronicity begins to be lost from 6 h to 8 h, potentially indicating the onset of cellularization. In g, all nuclei appear to be coming out of telophase; however, in h, nuclei appear in metaphase, telophase and interphase, with some showing decondensed chromatin.