cvl2 is co-expressed with bmps and positively regulated by Bmp signaling. (A) Domain composition of Cvl2 compared with the CR domain proteins Chordin (Sasai et al., 1994), Neuralin (Coffinier et al., 2001) and Kielin (Matsui et al., 2000). Blue boxes indicate signal peptide; red boxes indicate CR domains; yellow boxes indicate vWFd domain; gray box indicates the Thrombospondin domain; numbers one the right indicate total number of amino acid residues. (B) Temporal expression profile of cvl2 determined by RT-PCR. cvl2 is only zygotically expressed. (C-K) Spatial expression pattern determined by in situ hybridization; developmental stage is indicated in lower left-hand corner; genotype of embryos is indicated on the right-hand side. (C-E) Lateral views, ventral leftwards. (F,H) Frontal views, focal plane of H is indicated in G. (G) Animal pole view on head, ventral leftwards. Filled arrows in E-H indicate anterior lateral mesoderm; open arrows in D,F indicate prechordal plate; arrowhead in E indicates ventral tailbud mesoderm. (I-K) Vegetal views, ventral leftwards, with dorsal borders of the expression domain indicated by arrows. (I,J) cvl2 expression is expanded dorsally in chordin mutants. (I,K) Ventral expression is absent in bmp2b mutants. (L-N) Late cvl2 expression at 34 hpf in otic vesicle (arrowhead in L) and pharyngeal pouches (arrows in L) is elevated in hsp70::bmp2b transgenic (M), but downregulated in hsp70::noggin3 transgenic (N) embryos after a 30 minutes heatshock (28°C to 39°C) at 26 hpf.