Back to our roots

  title={Back to our roots},
  author={Helen R. Pilcher},
It was cold and clammy, but it changed the rules of life for ever. Helen Pilcher goes in search of the ancestor of all animals.Meet the ancestorSponges are the nearest living relatives of the first multicellular animal, a batch of single-celled organisms that came together in the ocean 600 million years ago. They have an immune system, signalling pathways and various cell types. By comparing the biology of the sponges with that of today's single-celled and complex animals, geneticists are… 

Paleoclimate and evolution: emergence of sponges during the neoproterozoic.

These studies confirmed the view that the sponges evolved between two epochal ice times, 710-680 Ma (Sturtian glaciation) and 605-585 Ma (Varanger-Marinoan ice age), a period which allowed evolution to proceed but resulted also in a mass extinction of most animal taxa, with the exception of the Porifera.

The stem cell concept in sponges (Porifera): Metazoan traits.

  • W. Müller
  • Biology
    Seminars in cell & developmental biology
  • 2006

Effect of Bacterial Infection on Stem Cell Pattern in Porifera

It is shown that after exposure to the endotoxin LPS (lipopolysaccharide) a differential gene expression occurs, leading to an upregulation of the gene encoding perforin and a concomitant down-regulation of noggin, a stem cell marker, which suggests that in response to bacterial infection the number of stem cells in sponges decreases.

Life as a Cosmic Phenomenon: 2.The Panspermia Trajectory of Homo sapiens

It is argued that the current evolutionary status of Homo sapiens as well as its future trajectory is circumscribed by evolutionary processes that were pre-determined on a cosmic scale – over vast distances and enormous spans of cosmic time.

The unique invention of the siliceous sponges: their enzymatically made bio-silica skeleton.

It is proposed that the key innovation that allowed the earliest metazoans to form larger specimens was the enzyme silicatein, crucial for the formation of the siliceous skeleton.

Formation of giant spicules in the deep-sea hexactinellid Monorhaphis chuni (Schulze 1904): electron-microscopic and biochemical studies

It is suggested that, in the Hexactinellida, the growth of the spicules is mediated by silicatein or by a silicatesin-related protein, with the orientation of biosilica deposition being controlled by lectin and collagen.

Sustainable Exploitation and Conservation of the Endemic Lake Baikal Sponge (Lubomirskia baicalensis) for Application in Nanobiotechnology.

The application of molecular biological and cell biological techniques has allowed an insight into the richness of the genomic regulatory systems of L. baicalensis, which dominates Lake Baikal's littoral-zone benthos and is a reference animal for other endemic sponges of this area, such as in the Tuva region.

Giant basal spicule from the deep-sea glass sponge Monorhaphis chuni : synthesis of the largest bio-silica structure on Earth by silicatein

Experiments suggest that the spicules function in vivo as a nonocular photoreception system, endowing it with unusual optophysical properties, which are superior to those of man-made waveguides.

Genetic, biological and structural hierarchies during sponge spicule formation: From soft sol-gels to solid 3D silica composite structures

This article attempts to overcome the frontiers in the understanding of the different levels of hierarchies, genetic, biological and structural, and to contribute towards the fabrication of new bioinspired functional materials.



Sponge Development and Antiquity of Animal Pattern Formation1

Observations of embryogenesis and metamorphosis in the demosponge Reniera suggest that the last common ancestor to all extant metazoan lineages already possessed the basic regulatory genetic architecture to direct the specification, patterning and differentiation of multiple cell types.

Evolution of Key Cell Signaling and Adhesion Protein Families Predates Animal Origins

Choanoflagellates express representatives of a surprising number of cell signaling and adhesion protein families that have not previously been isolated from nonmetazoans, including cadherins, C-type lectins, several tyrosine kinases, and tyrosINE kinase signaling pathway components.

Molecular evolution of integrins: genes encoding integrin beta subunits from a coral and a sponge.

CDNAs encoding integrin beta subunits from a coral and a sponge are identified and sequenced, indicating that these proteins existed in the earliest stages of metazoan evolution.

Evolution of Metazoan Cell Junction Proteins: The Scaffold Protein MAGI and the Transmembrane Receptor Tetraspanin in the Demosponge Suberites domuncula

It is concluded that sponges contain epithelia whose cells are organized by cell junctions, similar to other metazoan animal phyla that exist exclusively in tight junctions.

Stimulation of protein (collagen) synthesis in sponge cells by a cardiac myotrophin‐related molecule from Suberites domuncula

It is shown that a myotrophinlike polypeptide from the sponge Suberites domuncula causes the expression of collagen in cells from the same sponge in vitro, and it is concluded that the sponge myOTrophin causes in homologous cells the same/similar effect as the cardiac myotrophic effect in mammalian cells, where it is involved in initiation of cardial ventricular hypertrophy.

Carbon isotope evidence for the stepwise oxidation of the Proterozoic environment

Trends in the carbon isotope composition of sedimentary organic carbon and carbonate show that during the Proterozoic aeon the organic carbon reservoir grew in size, relative to the carbonate reservoir, mostly during episodes of global rifting and orogeny.

The Molecular Basis for the Evolution of the Metazoan Bodyplan: Extracellular Matrix-Mediated Morphogenesis in Marine Demosponges

This study demonstrates for the first time that an extracellular matrix molecule, galectin, induces a morphogenetic process in sponges which is very likely caused by a LIM/homeobox protein.