The novel Drosophila tim(blind) mutation affects behavioral rhythms but not periodic eclosion

Genetics. 2005 Feb;169(2):751-66. doi: 10.1534/genetics.104.036244. Epub 2004 Nov 1.

Abstract

Circadian clock function depends on the tightly regulated exclusion or presence of clock proteins within the nucleus. A newly induced long-period timeless mutant, tim(blind), encodes a constitutively hypophosphorylated TIM protein. The mutant protein is not properly degraded by light, and tim(blind) flies show abnormal behavioral responses to light pulses. This is probably caused by impaired nuclear accumulation of TIM(BLIND) protein, which we observed in brain pacemaker neurons and photoreceptor cells of the compound eye. tim(blind) encodes two closely spaced amino acid changes compared to the wild-type TIM protein; one of them is within a putative nuclear export signal of TIM. Under constant conditions, tim(blind) flies exhibit 26-hr free-running locomotor rhythms, which are not correlated with a period lengthening of eclosion rhythms and period-luciferase reporter-gene oscillations. Therefore it seems possible that TIM--in addition to its well-established role as core clock factor--functions as a clock output factor, involved in determining the period length of adult locomotor rhythms.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Substitution
  • Animals
  • Base Sequence
  • Behavior, Animal / physiology*
  • Biological Clocks / genetics*
  • Biological Clocks / physiology
  • Chromosome Mapping
  • Drosophila / genetics*
  • Drosophila Proteins / chemistry
  • Drosophila Proteins / genetics*
  • Insect Proteins / chemistry
  • Insect Proteins / genetics
  • Nervous System Physiological Phenomena
  • Photoreceptor Cells, Invertebrate / physiology
  • Point Mutation*
  • Protein Structure, Tertiary

Substances

  • Drosophila Proteins
  • Insect Proteins
  • tim protein, Drosophila