Imprecise excision of P{lacW}Spt-ISH1626 resulting in a 1.6 kb deletion including the start codon of Spt-I.
Estimated boundaries of a 1594 bp deletion resulting from the imprecise excision of P{lacW}Spt-ISH1626, which removes the first exon and part of the second exon of Spt-I as well as 5'UTR sequences of the upstream gene GLaz on the opposite strand.
Complementation crosses of Spt-Il(2)49Fb-1, Spt-Il(2)49Fb-4 or Spt-IJO8 to each other are lethal at first instar.