ZP genes in avian species illustrate the dynamic evolution of the vertebrate egg envelope.
The vertebrate egg envelope is composed of a set of related proteins, encoded by the ZP genes. The apparent simplicity of the egg envelope is in contrast to the number of ZP genes identified by conventional cloning and data mining of genome sequences from a number of vertebrates. The vertebrate ZP genes fall into five classes, ZP1, ZP2, ZP3, ZPD and ZPAX. Analysis of chicken genome and EST sequence data has revealed the presence of seven distinct ZP genes, falling into these classes that are expressed in the female reproductive system. Comparison with the repertoire of ZP genes in other vertebrates suggests a major source of diversity in the composition of the egg envelope is a continual process of amplification, diversification and attrition of ZP gene sequences.
Hughes
D C
DC
School of Biomedical & Natural Sciences, Nottingham Trent University, Nottingham, UK. david.hughes02@ntu.ac.uk
D000818:Animals; D001717:Birds / Q000235:genetics*; D004527:Egg Proteins / Q000235:genetics*; D019143:Evolution, Molecular; D016678:Genome / Q000235:genetics; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics*; D010063:Ovum / Q000166:cytology* / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000235:genetics*; D026801:Synteny; D000072216:Zona Pellucida Glycoproteins
D004527:Egg Proteins; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; C000606514:ZP1 protein, human; C000606515:ZP2 protein, human; C000606517:ZP3 protein, human; D000072216:Zona Pellucida Glycoproteins