TABLE 1.

U1 snRNA constructs used to inactivate the β-Gal, CAT, and GFP target genes

Construct name(s)	Target sequence	Whole sequencea
U1 snRNA	CAGGTAAGTA	Not applicable
U1antiβ-gal 1800	CAGTTCTGTA	5′GGCCCAAGATCTCATACAGAACTGGCAGG3′
U1antiCAT 488	CAGGTTCATC	5′GGCCCAAGATCTCAGATGAACCTGGCAGG3′
U1antiCAT 568	CAGGTTCATC	5′GGCCCAAGATCTCAGATGAACCTGGCAGG3′
U1antiGFP 490	CCGACAAGCA	5′GGCCCAAGATCTCATGCTTGTCGGGCAGG3′
U1antiCAT 737	CAGAAATTCG	5′CCCAAGATCTCACGAATTTCTGGCAGGGGAGATACC3′
U1antiCAT 737PvuII	CAGCTGTATA	5′CCCAAGATCTCATATACAGCTGGCAGGGGAGATACC3′
U1anti737a and U1antiCAT737Δ70K	CAGAAATTCG	5′CCCAAGATCTCACGAATTTCTGGCAGGGGAGATACC3′

^aUnderlined bases indicate the BglII restriction site used to insert the mutagenized DNA into the context of the U1 snRNA expression vectors. The last three sequences have an additional 9 bp at the 3′ end (italicized) which its complementary to the U1 gene from bp 14 to 22.