Piwil1^tm1Hfl

15.5 kb of the gene spanning exons 3-22 were replaced with a loxP-flanked PGK-neo cassette preceded by a GFP reporter gene. The targeting event results in a GFP fusion product after the first 9 amino acids of the gene. Western blot and immunofluorescent microscopy of testis from homozygous mutant animals verified the absence of Piwil1 expression. (J:77015)