Figure 4.

Expression of Bf-Tdrd7 during embryonic development. (A-G) Bf-Tdrd7 transcripts are only expressed maternally until late cleavage stage, and no zygotic Bf-Tdrd7 expression can be detected. Embryos in A, D, E are in lateral view with the animal side up and vegetal side down; B and C are in vegetal view; embryos in F and G are in left view with the anterior to the left. Black arrowheads indicate the aggregated maternal Bf-Tdrd7 mRNA. Scale bars, 50 μm, can be applied to embryos in the same developmental stage. (H-J) Colocalization of Bf-Tdrd7 and Bf-Vasa mRNAs in cleavage-stage amphioxus embryo. Images are in lateral view. White arrowheads indicate Bf-Tdrd7 and Bf-Vasa signals. Dashed lines indicate the outline of the embryos.