Fig. 4. Transgene sites visualised in root interphase nuclei of transgenic wheat lines after germination in water (control) or in the presence of 5-AC or TSA. Two lines are illustrated: line 6 (A-F), which carries five transgene copies at two sites on metaphase chromosomes; and line 2 (G-L), which carries more than 10 transgene copies at four sites on metaphase chromosomes (Abranches et al., 2000). The number of sites was determined by computer modelling of the entire 3D stacks as described by Abranches et al. (Abranches et al., 2000). Note that in the single confocal sections, only some of the sites present in the full 3D data from which the models were made are visible. The sites clearly visible on the single optical sections shown are indicated by arrows. (A) Single confocal section from line 6: control seedling germinated on water. (B) Single confocal section from line 6 after 5-AC. (C) Single confocal section after TSA. (D) Model from complete 3D data stack shown in A. The four nuclei each show two sites — one per homologue. (E) Model from the 3D stack shown in B. Three G1 nuclei (a,b,c) each show four sites, the G2 nucleus (d) shows eight sites. (F) Model from 3D stack shown in C. Each of the four nuclei show four sites. (G) Single confocal section from line 2 control seedlings germinated on water. (H) Single confocal section from line 2 after 5-AC. (I) Single confocal section from line 2 after TSA. (J) Model from the 3D stack shown in G. Three nuclei (a,c,d) show one site each and nucleus b shows two sites. (K) Model from the 3D stack shown in H. Four sites are shown in nucleus a and two or three sites are shown in nuclei b and c, respectively. (L) Model from the 3D stack shown in I. Two nuclei (a,d) show four sites each and the other two (b,c) show two or three sites each, respectively. Bar.10 µm (A-C,G-I).