Tg(FRG1,FRG2,DUX4*)34Maar

The transgene contains two co-injected PAC clones. PAC clone 226K22 contains the complete genomic sequences of the human FRG1 gene, TUBB7P pseudogene and FRG2 gene. PAC clone 202J3 contains a genomic fragment extending from the inverted D4Z4 repeat unit through the D4Z4 repeat region. This D4Z4 region has twelve-and-a-half copies of the D4Z4 macrosatellite repeat units (each unit has exons 1-2 of the DUX4 retrogene; with exon 1 encoding a double homeobox transcription factor), the region telomeric to the last repeat (called pLAM) contains the DUX4 exon 3 (harboring the FSHD-permissive haplotype 4A161 polyA signal) and lacks the more downstream DUX4 exons 4-7 (per primary investigator). The primary investigator reports that resizing efforts in 2015 suggest that D4Z4-12.5 transgenic mice carry an array of 15.5 D4Z4 repeat units. The two PAC transgenes recombined as a single overlapping ~183 kbp integration on chromosome 2. DUX4 mRNA was detected in germline tissues. In analyzed somatic tissues, transcripts are detected only in the tibialis anterior and pectoralis muscles, whereas all other somatic tissues do not show reproducible DUX4 expression. (J:195481)