<i>dino</i> and <i>mercedes</i>, two genes regulating dorsal development in the zebrafish embryo

TLDR

The genes dino and mercedes function in ventrolateral mesoderm patterning and neuroectoderm induction, analogous to the Spemann organizer in amphibians. This study identifies dino and mercedes as essential genes for organizing the zebrafish body plan. Dino mutants exhibit a ventralized phenotype with an enlarged tail and reduced head, evident before gastrulation, whereas mercedes mutants display a milder version, indicating both genes are required for dorsal fate establishment in the marginal and animal zones.

Abstract

We describe two genes, dino and mercedes, which are required for the organization of the zebrafish body plan. In dino mutant embryos, the tail is enlarged at the expense of the head and the anterior region of the trunk. The altered expression patterns of various marker genes reveal that, with the exception of the dorsal most marginal zone, all regions of the early dino mutant embryo acquire more ventral fates. These alterations are already apparent before the onset of gastrulation. mercedes mutant embryos show a similar but weaker phenotype, suggesting a role in the same patterning processes. The phenotypes suggests that dino and mercedes are required for the establishment of dorsal fates in both the marginal and the animal zone of the early gastrula embryo. Their function in the patterning of the ventrolateral mesoderm and the induction of the neuroectoderm is similar to the function of the Spemann organizer in the amphibian embryo.