Figure 2.

(a and b) Decidual swellings from intercrosses of top3α^+/− mice 8.5 dpc (a) and 10.5 dpc (b). (c and d) Histological sections of 7.5-dpc deciduae from intercrosses of top3α^+/− mice. Whereas these decidual swellings showed a uniform external appearance, two distinct types were revealed by sectioning: the majority contained embryos of normal appearance, such as the one shown in c, and the remaining were devoid of embryonic material, such as the one shown in d. Embryos of normal appearance were invariably found by genotyping to possess at least one copy of unaltered TOP3α. The bars correspond to a length of 100 μm.