Generation of Stra8-Cre/ERT2 Mouse Activator Strain for Inducible Cre-lox Recombination in Spermatocytes

Reverse genetics often requires systems that allow intended induction of toxic genes or inactivation of vital genes at a chosen moment and/or in a chosen tissue. Cre-lox recombination is a common tool of genetic engineering and is used to conditionally knock out a gene, in which an exon is preliminarily flanked with loxP sites, or to induce expression of a gene, in which a loxP-flanked STOP cassette is preliminarily inserted between the promoter and the open reading frame. A mouse strain, Stra8-Cre/ER^T2, was constructed to allow tamoxifen induction of Cre-lox recombination in spermatocytes. Construction was performed using a 400-bp promoter of the Stra8 gene, whose protein product STRA8 initiates the transition from mitosis to meiosis in response to a growing concentration of retinoic acid in the cell. The strain will be further used to study the regulatory mechanisms of meiosis.