A tubulin promoter drives expression of vtd, which is tagged 12bp upstream of the translational stop codon with 10 copies of Tag:MYC. In addition, an SpeI site has been introduced into the vtd coding region after amino acid residue 271, and 3 tandem copies of the Tag:CS(TEVp) protein cleavage tag have been introduced into this site (this sequence allows cleavage of the vtd protein by TEV\NIa). The portion of the construct containing the vtd coding region and a 3'UTR sequence is flanked by an FRT cassette.
The presence of a TEV protease cleavable form of vtd (by expressing vtd271TEV.tub.T:Zzzz\TEV.CS,T:Hsap\MYC and Zzzz\NIaScer\UAS.T:SV5\V5,T:SV40\nls2 in a vtdex3 mutant background) suppresses the chromosome segregation defects seen in embryos expressing aldScer\UAS.cAa under the control of Scer\GAL4mat.αTub67C.T:Hsim\VP16 in a mad2G6595 mutant background. This suppression does not occur in the absence of Zzzz\NIaScer\UAS.T:SV5\V5,T:SV40\nls2.