0000000000226465
AUTHOR
Cristiano C. Coutinho
Origin of the metazoan bodyplan: characterization and functional testing of the promoter of the homeobox gene EmH-3 from the freshwater sponge Ephydatia muelleri in mouse 3T3 cells.
Porifera [sponges] represent the lowest metazoan phylum, probably already existing prior to the 'Cambrian explosion'. Based on amino acid sequences deduced from cDNAs that code for structural proteins, the monophyly of Metazoa was established. Now we analyzed for the first time a promoter of a sponge gene for its activity in a heterologous cell system from higher Metazoa. The promoter of the homeobox gene EmH-3 was cloned and sequenced from a genomic library of the freshwater sponge Ephydatia muelleri. For the determination of functional promoter activity, transient transfection experiments in mouse NIH 3T3 cells were performed; the promoter was fused with the luciferase reporter gene. The …
Sponges (Porifera) Molecular Model Systems to Study Cellular Differentiation in Metazoa
Evolution is a gradual process whereby primarily new genes are formed either by gene duplication (Ohno 1970) or exon shuffling (Gilbert 1978). New proteins can also be produced by overlapping genes, alternative splicing or gene sharing (Li and Graur 1991). These facts imply that (1) proteins found in a given phylum contain elements or modules which are present already in ancestral protein(s) of members of phylogenetically older phyla and (2) that new combinations of such modules create proteins that possess new functions.