U2af38 cDNA is expressed under the control of a U2af50 promoter.
wild-type
U2af38U2af50.PR rescues U2af3806751
U2af38U2af50.PR fails to rescue U2af38ΔE18
U2af38U2af50.PR in combination with U2af38tRb partially rescues U2af38ΔE18.