Xhmg-at-hook1-3 expression analyses.

(A) RT-PCR analysis of Xhmg-at-hook and ODC transcription during Xenopus laevis development. Numbers refer to embryo stages. (B–G) Results of WISH on Xenopus laevis embryos. (B–B’) Stage 2: Xhmg-at-hook maternal transcripts are localised in the animal pole (ap). (C) Stage 22: faint staining is detectable in both the developing eye (white arrowhead) and CNS (black arrowhead). (D) Stage 25: Xhmg-at-hook expression is in the anterior half of the embryo around branchial pouches (black arrows). (E, F, G) At tailbud stages 31, 35–36, 39 respectively, labelling is present in the brain, eye, neural tube (nt), somites (som) and branchial region (f, forebrain; m, midbrain; h, hindbrain; ov, otic vesicles; cg, cement gland; vp, vegetal pole). (H) Transversal section of a stage 28 hybridised embryo showing Xhmg-at-hook mRNA presence in the brain region, eye vesicles (white arrowhead) and NCC derived-mesenchyme around the pharynx (arrows) (H). (I) Horizontal section of a stage 33 hybridised embryo showing Xhmg-at-hook mRNA presence in the NCC derived pharyngeal arches (arrows).