Figure 4. Whole-mount in situ hybridization assays at early developmental stages illustrating the common expression patterns of 14 up-regulated genes: Nrp1, Arrb2, BG022063, LOC100037047, BQ399495, Hrpt1, Rbm42-6, LOC414689, Uncx4.1, Xxylt1, Nfya, Tbc1d31, Cdca7l, Papd4-a. For all genes, expression is enhanced in the animal cells (an) of cleavage and blastula embryos (side views). At gastrula stages, expression is throughout the ectoderm, occasionally enhanced in the animal cells (e.g., Arrb2) or the dorsal cells (e.g., Nrp1) (side views). At early neural plate stages, all genes are expressed in the epidermis (epi), often more intensely on the dorsal (d) side, including neural plate (np) and border zone (bz) (all except Nrp1 are side views with anterior [a] to the left; Nrp1 is an anterior view with dorsal to the top). At late neural plate and neural tube stages, expression is strongest in the neural crest (nc), pre-placodal region (ppr), neural tube (nt) and occasionally cement gland (cem) (all are anterior views). For Nrp1, embryos were sectioned in the horizontal plane to demonstrate that the ppr stripe in the whole embryo is due to expression in the deep (d) layer of the ectoderm, not the superficial (s) layer of the ectoderm or the pharyngeal endoderm (phe); ph, lumen of pharynx.