Fig. 9

Cav-1 proteins from different species mediate conserved ventralizing activity. (A) Amino acid sequence analysis of human and zebrafish Cav-1 (GenBank # of human Cav-1α and -1β: NP_001744 and ABW22626; GenBank # of zebrafish Cav-1α and -1β: NP_997816 and NP_001019333). Caveolin scaffolding domain was shown in a red box. (B) Overexpression of human cav-1 ventralizes zebrafish embryos. Embryos at one-cell stage were injected with 300 pg human cav-1α or -1β mRNA. Total ventralized embryos (T) were divided into three groups: mild (M), intermediate (I) and severe (S). (C) Expression patterns of dorsoventral genes in embryos injected with 300 pg human cav-1α mRNA, 300 pg human cav-1β mRNA, 150 pg human cav-1α mRNA plus 10 ng zebrafish cav-1α-MO, or 150 pg human cav-1β mRNA plus 10 ng zebrafish cav-1β-MO. Developmental stages are shown at the bottom. Animal pole views of embryos at shield stage with the dorsal toward the right for chordin and eve1. Dorsal views of embryos at shield stage with animal pole toward the top for gsc. Lateral views of embryos at shield stage with the dorsal toward the right for bmp2b. Lateral views of embryos at 24 hpf with anterior to the left for gata1. (D–E)Percentage of embryos with decreased or increased expression of marker genes in (C). Total numbers of embryos examined are indicated at the bottom. (F) Co-injection of 150 pg human cav-1α mRNA into embryos at one-cell stage blocked activation of the Top-flash luciferase reporter by injection of 150 pg β-cat mRNA, but not that by injection of 150 pg β-cat-M mRNA. **indicates p < 0.01 vs. embryos injected with Top-flash plus β-cat mRNA.