Fig. 9.

Expression analysis of select developmental regulators in early Platynereis development. To confirm the validity of the expression profiles of specific genes from the transcriptome assembly, whole-mount in situ hybridization (WMISH) was performed (images on the right). The graphs on the left depict the temporal expression profiles of nodal, hes-like 1, bmp2/4, and fz5/8. The expression level is in FPKM, and the two bars at each stage represent biological replicates. a Expression of the secreted ligand nodal. RNA-sequencing indicates expression is initiated at 6 h post fertilization (hpf). WMISH of 6hpf embryos confirms expression of nodal in a single cell at this developmental stage. b Expression of the novel Hes family transcription factor hes-like 1. hes-like 1 is initially expressed at 4hpf with the peak of expression at 6hpf. hes-like 1 expression can be seen with WMISH on 6hpf embryos in the four animal-most cells. c Expression of the secreted ligand bmp2/4. RNA-sequencing indicates expression begins at 4hpf and declines slowly over the next ten hours. WMISH confirms expression in early development with expression in one cell at 6hpf and two cells at 8hpf (only one can be seen in the image shown). d Expression of the Wnt receptor fz5/8. Both biological replicates have expression at 6hpf according to the RNA-sequencing data. With WMISH, expression of fz5/8 can be seen at 6hpf in the four animal-most cells. Expression of fz5/8 continues in the animal-most cells at 8hpf, with expression in four cells called the rosette cells