sev enhancers and an Hsp70 promoter drive expression of a mutated form of csw, in which amino acids 290 to 444 are deleted.
cswΔin.hs.2sev rescues cswG547E.hs.2sev
cswΔin.hs.2sev rescues csw13-87
Rescues the zygotic lethality of csw13-87/Y males. Also has maternal csw+ function; homozygous females carrying cswhs.2sev produce wild-type progeny.