Piwi-interacting RNAs (piRNAs), a discrete class of small RNAs, are expressed in mammalian germline cells and play a critical role in germline development. Arising from discrete genomic loci (clusters), they are selected from long precursor transcripts through unknown mechanisms to guard germ cell genomes against the activity of mobile genetic elements.
This BAC-derived transgene encodes approximately 100 kb of a mouse Chromosome 17 piRNA cluster (mm9 assembly Chr. 17:27427600-27488899) and incorporates a GFP marker inserted antisense to the direction of transcription. Expression of the transgene recapitulates that of the endogenous locus, with transcription starting in male germ cells post-puberty. GFP-tagged antisense piRNAs are produced during male meiosis. No sense GFP is expressed, thus no fluorescence can be detected.
This transgenic strain demonstrates that piRNA clusters can be separated from their native genomic locations and contain sufficient information to funnel their RNA products into the piRNA biogenesis pathway.
No phenotypic differences between founder lines 13 and 37 (see Stock No. 019494) have been noted.
