Absence of PTEN/MMAC1 pseudogene in mice

The PTEN gene encodes a phosphatase that acts as a tumor-suppressor gene an d is mutated in a variety of human cancers. Alterations of the PTEN gene in these tumor samples were identified using exon-by-exon analysis of the gen e using single-stranded conformational polymorphism or direct sequencing of PTEN cDNA, However, in humans, mutational analysis of a PTEN cDNA template can produce false results because of a highly conserved PTEN processed pse udogene that shares more than 98% homology with the coding region of functi onal PTEN. PTEN-knockout mice develop tumors, suggesting that mouse tumor m odels are useful in vivo model systems to study PTEN function. Any mutation al analysis of mouse PTEN cDNA may also produce false results if mice conta in a highly conserved PTEN pseudogene. In this paper, we demonstrate the ab sence of any PTEN pseudogene in the mouse and discuss the significance of t his observation for the mutational studies of the PTEN gene in mouse tumor models.