A temperature-sensitive behavioural mutant of Drosophila melanogaster: Out-coldts

The paralytic behaviour of a new mutant in Drosophila melanogaster is described. The mutant, which is called Out-cold temperature-sensitive (Ocdts) (1–55,2), is a dominant reversibly paralytic mutant. The paralysis occurs when heterozygous Ocdts females are shifted from 25°C to temperatures below 18°C-20°C. Storage at low temperatures does not kill Ocdts/ + females. Heterozygous female Ocdts flies behave normally at 25°C in contrast to Ocdts males which walk in a reeling manner, fall over frequently, and usually die within 48 hours regardless of the temperature. By deletion mapping the Ocdts mutation was located to a region on the X-chromosome delimited by the bands 14A1 and 14C8.