Mapping the Clock Rhythm Mutation to the Period Locus of Drosophila Melanogaster by Germline Transformation

Abstract

The Clock (Clk) mutation shortens circadian rhythms of locomotor activity and eclosion from ca. 24 h to 22.5–23 h. Clk was previously mapped, by meiotic recombination, very close to the period(per) locus on the X chromosome. To determine whether Clk is a mutation within the per gene or if the former is separate from the latter, two overlapping genomic fragments were cloned from Clk flies to produce a per-containing 13.2 kb construct, per⁰¹ flies (which by themselves are arrhythmic)—when transformed with this construct—-expressed short-period rhythms. This indicates that the Clk mutation is contained within this 13.2 kb region and is almost certainly a new “fast-clock” allele of per.

Key Words:

• circadian rhythms
• locomotor activity
• P-element transgenics