Search results for "Metazoa"
showing 10 items of 12 documents
Organic matrices in metazoan calcium carbonate skeletons: composition, functions, evolution.
2016
9 pages; International audience; Calcium carbonate skeletal tissues in metazoans comprise a small quantity of occluded organic macromolecules, mostly proteins and polysaccharides that constitute the skeletal matrix. Because its functions in modulating the biomineralization process are well known, the skeletal matrix has been extensively studied, successively via classical biochemical approaches, via molecular biology and, in recent years, via transcriptomics and proteomics. The optimistic view that the deposition of calcium carbonate minerals requires a limited number of macromolecules has been challenged, in the last decade, by high-throughput approaches. Such approaches have made possible…
Characterization and phylogenetic analysis of a cDNA encoding the Fes/FER related, non-receptor protein-tyrosine kinase in the marine sponge Sycon ra…
1998
Abstract In search of ancient versions of phylogenetically conserved genes/proteins, which are typical for multicellular animals, we have decided to analyse marine sponges (Porifera), the most ancient and most primitive metazoan organisms. We report here the complete nucleotide sequence of Sycon raphanus cDNA coding for a 879 aa long protein (100 kDa), which displays high overall similarity in primary structure and organization of domains with non-receptor tyrosine kinases (TKs) from the Fes/FER family. The encoded protein, which we named Fes/FER_SR, has a highly conserved, 260 aa long tyrosine kinase domain at the C-terminus. Amino-terminal to the catalytic domain is an 85 aa long SH2 doma…
Tardigrades of Finland: new records and an annotated checklist
2020
Species checklists are powerful and important tools of communication between taxonomists and applied environmental biologists, which in turn lead to well-planned and successful conservation strategies and ecological studies. Despite this, only recently the interest on compiling systematic checklists is growing among taxonomists who study tardigrades—micrometazoans that inhabit almost every habitat worldwide. As the Finnish records of tardigrades (a.k.a. water bears) species are incomplete, outdated and no checklist has ever been compiled for this country, an easy-to-consult checklist is here reported. This checklist covers all Finnish tardigrade taxa identified in the past and in the 13 sam…
The complete set of ribosomal proteins from the marine sponge Suberites domuncula
2005
The siliceous marine sponge Suberites domuncula is a member of the most ancient and simplest extant phylum of multicellular animals-Porifera, which have branched off first from the common ancestor of all Metazoa. We have determined primary structures of 79 ribosomal proteins (r-proteins) from S. domuncula: 32 proteins from the small ribosomal subunit and 47 proteins from the large ribosomal subunit. Only L39 and L41 polypeptides (51 and 25 residues long in rat, respectively) are missing. The sponge S. domuncula is, after nematode Caenorhabditis elegans and insect Drosophila melanogaster the third representative of invertebrates with known amino acid sequences of all r-proteins. The comparis…
The evolution of metazoan α-carbonic anhydrases and their roles in calcium carbonate biomineralization
2014
The carbonic anhydrase (CA; EC 4.2.1.1) superfamily is a class of ubiquitous metallo-enzymes that catalyse the reversible hydration of carbon dioxide. The ?-CA family, present in all metazoan clades, is a key enzyme involved in a wide range of physiological functions including pH regulation, respiration, photosynthesis, and biocalcification. This paper reviews the evolution of the ?-CA family, with an emphasis on metazoan ?-CA members involved in biocalcification. Phylogenetic analyses reveal a complex evolutionary history of ?-CAs, and suggest ?-CA was independently co-opted into a variety of skeleton forming roles (e.g. as a provider of HCO3? ions, a structural protein, a nucleation activ…
Demosponge EST sequencing reveals a complex genetic toolkit of the simplest metazoans.
2010
Sponges (Porifera) are among the simplest living and the earliest branching metazoans. They hold a pivotal role for studying genome evolution of the entire metazoan branch, both as an outgroup to Eumetazoa and as the closest branching phylum to the common ancestor of all multicellular animals (Urmetazoa). In order to assess the transcription inventory of sponges, we sequenced expressed sequence tag libraries of two demosponge species, Suberites domuncula and Lubomirskia baicalensis, and systematically analyzed the assembled sponge transcripts against their homologs from complete proteomes of six well-characterized metazoans--Nematostella vectensis, Caenorhabditis elegans, Drosophila melanog…
Mitigating anticipated effects of systematic errors supports sister-group relationship between Xenacoelomorpha and Ambulacraria.
2019
International audience; Xenoturbella and the acoelomorph worms (Xenacoelomorpha) are simple marine animals with controversial affinities. They have been placed as the sister group of all other bilaterian animals (Nephrozoa hypothesis), implying their simplicity is an ancient characteristic ]; alternatively, they have been linked to the complex Ambulacraria (echinoderms and hemichordates) in a clade called the Xenambulacraria , suggesting their simplicity evolved by reduction from a complex ancestor. The difficulty resolving this problem implies the phylogenetic signal supporting the correct solution is weak and affected by inadequate modeling, creating a misleading non-phylogenetic signal. …
Molecular Phylogeny of Eumetazoa: Genes in Sponges (Porifera) Give Evidence for Monophyly of Animals
1998
At present, the universal phylogenetic tree exhibits a tripartite division of the living world and includes Bacteria (“eubacterial”), Archaea (“archebacterial”), and Eucarya (“eukaryotic”) branches (Woese et al. 1991) with the Progenote as the common ancestor (Woese 1987). It is difficult to assess the timely appearance of the first living organism. Some first decipherable evidence of early life has apparently been identified in Swaziland (South Africa) and Pilbara Supergroup (Western Australia) sediments, and dates back 3550 to 3000 Ma (million years) ago; these are stromatolites (see Walter 1996), microfossils, and particulate organic matter (reviewed in Schopf 1994). Eucarya are roughly …
Signal Recognition Particle 54 kD Protein (SRP54) from the Marine Sponge Geodia cydonium
2002
In the systematic search for phylogenetically conserved proteins in the simplest and most ancient extant metazoan phylum – Porifera, we have identified and analyzed a cDNA encoding the signal recognition particle 54 kD protein (SRP54) from the marine sponge Geodia cydonium (Demospongiae). The signal recognition particle (SRP) is a universally conserved ribonucleoprotein complex of a very ancient origin, comprising SRP RNA and several proteins (six in mammals). The nucleotide sequence of the sponge cDNA predicts a protein of 499 amino acid residues with a calculated Mr of 55175. G. cydonium SRP54 displays unusually high overall similarity (90 %) with human/mammalian SRP54 proteins, higher th…
Protein SRP54 iz morske spužve Geodia cydonium
2002
In the systematic search for phylogenetically conserved proteins in the simplest and most ancient extant metazoan phylum – Porifera, we have identified and analyzed a cDNA encoding the signal recognition particle 54 kD protein (SRP54) from the marine sponge Geodia cydonium (Demospongiae). The signal recognition particle (SRP) is a universally conserved ribonucleoprotein complex of a very ancient origin, comprising SRP RNA and several proteins (six in mammals). The nucleotide sequence of the sponge cDNA predicts a protein of 499 amino acid residues with a calculated Mr of 55175. G. cydonium SRP54 displays unusually high overall similarity (90 %) with human/mammalian SRP54 proteins, higher th…