ABSTRACT
Five novel genes homologous to the homeobox-containing genes Xanf-1 and Xanf-2 of Xenopus and Hesx-1/Rpx of mouse have been identified as a result of a PCR survey of cDNA in sturgeon, zebrafish, newt, chicken and human. Comparative analysis of the homeodomain primary structure of these genes revealed that they belong to a novel class of homeobox genes, which we name Anf. All genes of this class investigated so far have similar patterns of expression during early embryogenesis, characterized by maximal transcript levels being present at the anterior extremity of the main embryonic body axis. The data obtained also suggest that, despite considerable high structural divergence between their homeodomains, all known Anf genes may be orthologues, and thus represent one of the most quickly evolving classes of vertebrate homeobox genes.
Subject(s)
Genes, Homeobox , Homeodomain Proteins/chemistry , Vertebrates/genetics , Xenopus Proteins , Amino Acid Sequence , Animals , Body Patterning/genetics , Chickens , Embryo, Mammalian/physiology , Embryo, Nonmammalian/physiology , Evolution, Molecular , Fishes , Homeodomain Proteins/biosynthesis , Humans , Mice , Molecular Sequence Data , Multigene Family , Phylogeny , Polymerase Chain Reaction , Protein Structure, Secondary , Salamandridae , Sequence Alignment , Sequence Homology, Amino Acid , Vertebrates/embryology , ZebrafishABSTRACT
The level of cAMP and the effects of the regulatory and catalytic subunits of cAMP-dependent protein kinase of type II on protein, RNA and DNA synthesis in loach embryos were analysed. It was found that the injections of the catalytic subunit cause a sharp decrease in the rate of macromolecular synthesis while an increase in the concentration of this protein leads to the death of the embryo. Injections of the regulatory subunit result in marked stimulation of protein, RNA and DNA synthesis. The effect of the regulatory subunit on these processes is rather complex. Experiments on the transplantation of the nuclei from the embryos treated with the protein kinase subunits into normal embryos were carried out.
