UASp regulatory sequences drive expression of amino acids 1-350 and 1291-2051 of cno isoform PE. Amino acid replacements Y1553F, Y1565F, Y1652F, Y1679F, Y1727F, Y1800F, Y1875F, Y1927F, Y1932F, Y1948F, and Y1987F have been introduced into the cno coding sequence and it is tagged at the N-terminal end with msVenus.