Construct: Amino acid replacement: S540. Two copies of the sev enhancer linked to an Hsp70 promoter drive expression of a C-terminally truncated form of Src64B@ (contains the mutation described above) which lacks the putative negative regulatory residue Tyr547.
Expression of Src64BΔ540.hs.2sev under the control of heat shock in early embryos results in dramatic defects in cuticular structures, most notably deletion of the ventral denticle bands. The filzkorper are slightly enlarged.
Overexpression of Src64BΔ540.hs.2sev by heat shock at 37oC for 1 hour every other day during development is lethal. Over 95% of embryos carrying two copies of Src64BΔ540.hs.2sev show abnormalities when Src64BΔ540.hs.2sev is expressed using a 30 minute heat shock at 37oC between 5 and 8 hours of development. These include failure to undergo germ band retraction and grossly abnormal nervous system morphology, including asymmetries and extreme thinning of the longitudinal connectives. Expression of Src64BΔ540.hs.2sev in adults causes roughening of the eye. The regular array of the ommatidia is grossly distorted. 92% of the ommatidia contain an excess of photoreceptor cells with small rhabdomeres.
Src64BΔ540.hs.2sev has lethal | heat sensitive phenotype, suppressible by Ras85De2F
Src64BΔ540.hs.2sev has lethal | heat sensitive phenotype, suppressible by Df(3R)by10
Src64BΔ540.hs.2sev has visible phenotype, suppressible by sina3
Src64BΔ540.hs.2sev has visible phenotype, suppressible by Ras85De1B
Src64BΔ540.hs.2sev has eye phenotype, suppressible by Ras85De2F
Src64BΔ540.hs.2sev has eye phenotype, suppressible by sina3
Src64BΔ540.hs.2sev has eye phenotype, suppressible by Ras85De1B
The conditional lethal phenotype of animals expressing Src64BΔ540.hs.2sev is suppressed by Ras85De2F or Df(3R)by10. 80-90% of Ras85De2F/+ flies carrying one copy of Src64BΔ540.hs.2sev show a reduction in eye roughness relative to control flies carrying one copy of Src64BΔ540.hs.2sev in a Ras85D+ background; most of the extra R7-like cells are eliminated and much of the normal eye architecture is restored. The rough eye phenotype is also partially suppressed by Ras85De1B or sina3.