The phylogenetic relationships within the kingdom Animalia (Metazoa) have long been
questioned. Focusing on the lowest eukaryotic multicellular organisms, the metazoan …

Retinoic acid (RA) is a vitamin A‐derived morphogen important for axial patterning and
organ formation in developing vertebrates and invertebrate chordates (tunicates and …

Sponges (Porifera) represent the lowest metazoan phylum; they have been shown to be
provided with the characteristic metazoan structural and functional molecules. One …

Sponges were first grouped to the animal-plants or plant-animals then to the Zoophyta or
Mesozoa and finally to the Parazoa. Only after the application of molecular biological …

Sponges (Porifera) represent the lowest metazoan phylum, characterized by a pronounced
plasticity in the determination of cell lineages. In a first approach to elucidate the molecular …

Retinoid X receptors (RXR) are members of the nuclear receptor superfamily of ligand-
activated transcription factors that have been characterized in a wide variety of metazoan …

Retinoic acid (RA) is a vitamin A-derived morphogen controlling important developmental
processes in vertebrates, and more generally in chordates, including axial patterning and …

To date no nuclear receptors have been identified or cloned from the phylogenetically oldest
metazoan phylum, the Porifera (sponges). We show that retinoic acid causes tissue …

Cells from the freshwater sponge Ephydatia muelleri were isolated by dissociating hatching
gemmules. During the first 24 h the cells reaggregated, but the aggregates progressively …

All animals are capable of undergoing gametogenesis. The ability of forming haploid cells
from diploid cells through meiosis and recombination appeared early in eukaryotes …