Identification of a rat protein tyrosine phosphatase gene preferentially expressed in the embryonal brain.

We have identified a novel protein tyrosine phosphatase gene from an embryonal rat brain by reverse transcription-based polymerase chain reaction. Its transcription is specific to brain and is developmentally regulated, as it is expressed at high levels in embryonal and neonatal stages but scarcely in an adult. Southern blot analysis indicates that the gene exists as a single copy and is conserved among various species. Homology search of the deduced amino acid sequence suggests that this gene belongs to the same family of the membrane-type tyrosine phosphatase gene of Drosophila (DPTP10D), whose expression is specific to an central nervous system of fly embryo.