There are two temperature-sensitive periods during development, one during the second half of embryogenesis and one about the time of pupariation. In addition the mutation is a temperature-sensitive adult lethal; adults die 6-18 hours after eclosion at 29^oC. Adult flies also show temperature-sensitive paralysis, mosaic analysis reveals separate mesodermal foci for this phenotype. Embryos appear abnormal until 8-10 hours after laying at 29^oC, but by 11 hours after laying at 29^oC they are clearly abnormal, with diffuse and ill-defined body-wall musculature compared to wild-type.

Developmental studies show that there are lethal temperature-sensitive periods during embryogenesis and at pupariation, as well as during the adult stage. Mosaic analysis demonstrates mesodermal foci for a leg paralysis phenotype in mosaics retained at 29^oC. l(1)adl1¹/Df(1)HA11 flies have dark trident and uncoordinated leg phenotypes, even when raised at 22^oC.

Temperature shift and pulse experiments delineate two major temperature-sensitive periods, one during the second half of embryogenesis and the other at the time of pupation. Fate mapping revealed separate mesodermal foci for leg paralysis, and examination of embryos developing at 29^oC indicated abnormalities in muscle development (Homyk, Sinclair, Wong and Grigliatti, 1986). temperature-sensitive embryonic lethal temperature-sensitive paralysis adults die 0.25-0.75 days after eclosion at 29^oC.