Phylogenetic Position of the Hexactinellida Within the Phylum Porifera Based on the Amino Acid Sequence of the Protein Kinase C from Rhabdocalyptus dawsoni |
| |
Authors: | Michael Kruse Sally P Leys Isabel M Müller Werner EG Müller |
| |
Institution: | Institut für Physiologische Chemie, Abteilung Angewandte Molekularbiologie, Universit?t, Duesbergweg 6, 55099 Mainz, Germany, DE Department of Biology, University of Victoria, P.O. Box 1700, Victoria, B.C. V8W 2Y2, Canada, CA
|
| |
Abstract: | Recent analyses of genes encoding proteins typical for multicellularity, especially adhesion molecules and receptors, favor
the conclusion that all metazoan phyla, including the phylum Porifera (sponges), are of monophyletic origin. However, none
of these data includes cDNA encoding a protein from the sponge class Hexactinellida. We have now isolated and characterized
the cDNA encoding a protein kinase C, belonging to the C subfamily (cPKC), from the hexactinellid sponge Rhabdocalyptus dawsoni. The two conserved regions, the regulatory part with the pseudosubstrate site, the two zinc fingers, and the C2 domain, as
well as the catalytic domain were used for phylogenetic analyses. Sequence alignment and construction of a phylogenetic tree
from the catalytic domains revealed that the yeast Saccharomyces cerevisiae and the protozoan Trypanosoma brucei are at the base of the tree, while the hexactinellid R. dawsoni branches off first among the metazoan sequences; the other two classes of the Porifera, the Calcarea (the sequence from Sycon raphanus was used) and the Demospongiae (sequences from Geodia cydonium and Suberites domuncula were used), branch off later. The statistically robust tree also shows that the two cPKC sequences from the higher invertebrates
Drosophila melanogaster and Lytechinus pictus are most closely related to the calcareous sponge. This finding was also confirmed by comparing the regulatory part of the
kinase gene. We suggest, that (i) within the phylum Porifera, the class Hexactinellida diverged first from a common ancestor
to the Calcarea and the Demospongiae, which both appeared later, and (ii) the higher invertebrates are more closely related
to the calcareous sponges.
Received: 6 August 1997 / Accepted: 24 October 1997 |
| |
Keywords: | : Glass sponge — Rhabdocalyptus dawsoni— Hexactinellida — Protein kinase C — Phylogeny — Molecular systematics — Molecular evolution |
本文献已被 SpringerLink 等数据库收录! |
|