Fig. 2. Embryonic expression of E2f2. The expression of E2f2 was analyzed by whole-mount in situ hybridization of wild-type embryos of different developmental stages using an antisense E2F2 cDNA probe. Embryos are oriented with anterior towards the left and dorsal towards the top. (A) Maternal E2f2 mRNA can be detected in syncytial stage embryos. (B) A cellularizing blastoderm embryo, at which time maternal message has been destroyed. (C) A stage 10 germ band extended embryo. E2f2 is expressed throughout the embryo during the post-blastoderm divisions, but its expression is not coupled to the cell cycle. (D) A stage 13 germband retracted embryo. E2f2 expression is confined to dividing cells of the CNS (arrowhead) and endoreduplicating cells such as the gut (arrow). (E) A stage 15 germband retracted embryo. E2f2 expression is still confined to dividing and endocycling cells, and its expression is still not coupled to a particular cell cycle phase. (F) A stage 14 Df(2L)DS8/Df(2L)DS8 embryo. Zygotic E2f2 expression is lacking, indicating that this deletion removes the E2f2 gene.
