A wild type copy of polyhedrin is required to incorporate polyhedrin fragments into the crystal
. A, confocal microscopy images illustrating that the polyhedrin fragment PH(1–110)-EGFP forms aggregates inside the nuclei of infected cells (when expressed in the absence of WT polyhedrin). B, Tridimensional confocal reconstruction of a cell expressing PH(1–110)-EGFP. Notice the formation of aggregates inside the nucleus. C, The PH(1–110)-EGFP aggregates are visible in TEM as dense amorphous particles, and they do not contain baculoviruses inside. Notice that in fact viruses are excluded from the aggregates (C’ and C”, indicates as Bac and arrows, NM = nuclear membrane). D, Only the amino terminal fragment from polyhedrin can be incorporated into polyhedra crystals (when co-expressed with wild type polyhedrin). Notice that only the fragment PH(1–110)-EGFP form polyhedra (D’). The carboxyl terminus fragment PH(1–110)-EGFP is not incorporated into the polyhedra crystals, in fact it is excluded from the crystal and observed as a soluble protein in the cell cytosol (D”).