10xUAS sequences regulate expression of a "sponge" construct designed to knockdown the miR-1-3p, miR-9c-5p, miR-279-3p and miR-996-3p miRNAs. The sponge sequence consists of repeats of a 21bp sequence that is complementary to the targeted miRNA except for mismatches at positions 9-12, with a 4bp linker between each repeat; there are 20 sponge repeats targeting miR-1-3p, 20 sponge repeats targeting miR-9c-5p, 10 sponge repeats targeting miR-279-3p and 10 sponge repeats targeting miR-996-3p. The sponge sequences are inserted into 3'UTR sequence downstream of the DsRed2 coding region.