Phylogram of different vertebrate hairy/E(spl)-like proteins and Drosophila hairy. Circles indicate genes that are cyclically expressed and boxes indicate genes that are expressed in the PSM, but not cyclically. It is evident that the phylogenetic similarities and expression similarities do not correspond.

Comparison of the expression pattern of her1 and her7 during one cyclic phase by double fluorescent in situ hybridisation. (A-C) 5, (D-F) 5+, (G-I) 5++, (J-L) 6-somite stage. All in dorsal view, anterior to the top, flat-mounted embryos. (A,D,G,J) her1 expression, (B,E,H,K) her7 expression, (C,F,I,L) superimposition of the expression of both genes.

Effects of morpholino injections on the pattern of genes expressed in the PSM. (A-G) The wild-type pattern, (H-N) embryos injected with her1^mo and (O-U) embryos injected with her7^mo. Two different morpholinos were used in each case (see Materials and Methods), which caused identical effects, respectively. The embryos are between the 8- and 12-somite stage. The columns represent the different probes that were used for in situ hybridisation. her1_ex refers to a cDNA (exon) probe, her1_in to the intron probe. deltaC and deltaD are abbreviated. Two columns are shown for the her1_in and her7 probes, to show different stages of the dynamic expression. Note that the her1_in probe yields a much weaker signal and requires about 15-fold longer staining times than the exon probe (1 hour compared to approximately 15 hours). Moreover, it leads often to additional apparently random punctate expression in the PSM, which is of unknown significance. The embryos that are selected here have relatively few such additional punctate signals - some of the other embryos in the same preparations did show a higher number of these irregular signals. In total 185, 190, 88 and 84 her1^mo-injected embryos from independent experiments were hybridised with antisense riboprobes of her1, her7, deltaC and deltaD, respectively. The penetrance of the observed effects was 92%, 91%, 94% and 90%, respectively. In total 183, 163, 89 and 82 her7^mo-injected embryos from independent experiments were hybridised with antisense riboprobes of her1, her7, deltaC and deltaD, respectively. The penetrance of the observed effects was 96%, 92%, 91% and 91%, respectively. In total 230 her1^mo-injected embryos were hybridised with her1 intron probe. The observed penetrance in 3 independent experiments was 92%, 96% and 93%, respectively. All in dorsal view, anterior to the top, flat-mounted embryos.

GFP reporter gene mRNA expression and her1 expression in transgenic embryos with the 8.6 kb construct. (A-C) her1 probe, (D-(F) GFP probe and (G-H) both probes mixed. Whole-mount embryos, all in dorsal view, anterior to the top. The embryos are between the 10 and 12 somite stage. Note the ectopic GFP expression in the notochord in the transgenic line, which indicates a missing repressor element.

GFP reporter gene mRNA expression in the different transgenic lines. The roman numerals in A-F correspond to the construct numbers in Fig. 1. In A-G a*, m* and p* mark the anterior, middle and posterior stripes of GFP mRNA expression, respectively. Whole-mount embryos all in dorsal view, anterior to the top. The embryos are between the 12- and 14-somite stage.

Effects of morpholino injections on the GFP reporter mRNA expression in the PSM of the transgenic lines. Transgenic lines with (A-C) 8.6 kb of the upstream sequence and (D-F) 3.3 kb of the upstream sequence. (A,D) Uninjected control embryos, (B,E) her1^mo-injected embryos and (C,F) her7^mo-injected embryos. All in dorsal view, anterior to the top, flat-mounted embryos between the 10- and 12-somite stage.