Odor-guided behavior in Drosophila requires calreticulin

Abstract

The efficient processing of olfactory information is crucial for many aspects of life in animals, including behavior in insects. While much is known about the organization of the insect olfactory system, comparatively little is understood about the molecules that support its function. To further elucidate the molecular basis of olfaction, we explored the role of the calcium-binding chaperone calreticulin in the behavioral response of Drosophila to aversive odorants. We show that avoidance of naturally aversive odorants is impaired in flies harboring mutations in Calreticulin. Calreticulin mutants have broad defects in odor avoidance without abnormalities in antennal responses to odorants, alterations in central nervous system structure, or deficits in overall locomotor abilities. Interestingly, Calreticulin mutants exhibit defects in behavioral responses to odorants at low strength, whereas responses to higher odorant concentrations are preserved in these animals. Our studies indicate that calreticulin plays a key role in olfactory system function, possibly by establishing its overall sensitivity to odorants.

Delayed behavioural aging and altered mortality in Drosophilaβ integrin mutants

“…Northern analyses were performed on total RNA isolated from whole 1-to 3-day-old adult females using standard techniques (Stoltzfus et al, 2003). The mys probe was generated by labelling a mys + cDNA (kindly provided by D. Brower, University of Arizona).…”

“…Negative geotaxis was assessed as previously described (CookWiens & Grotewiel, 2002;Stoltzfus et al, 2003). Flies of the appropriate ages were briefly anaesthetized with CO 2 , sorted singly into food vials, and allowed to recover overnight (∼18 h) at 25 °C/ 65% relative humidity.…”

Quantitative Genetic Analysis of Sleep inDrosophila melanogaster

“…Calreticulin has many proposed functions, including a role in neural development (Prokopenko et al 2000;Norga et al 2003), protein folding, and calcium signaling and homeostasis (Krause and Michalak 1997;Johnson et al 2001). Calreticulin mutant flies have normal exploratory behavior and geotaxis (Stoltzfus et al 2003), but are sensitive to ether anesthesia (Gamo et al 1998). Furthermore, Calreticulin mutants exhibit impaired olfactory avoidance (Stoltzfus et al 2003;Sambandan et al 2006), yet respond normally to attractants (Stoltzfus et al 2003).…”

“…Calreticulin mutant flies have normal exploratory behavior and geotaxis (Stoltzfus et al 2003), but are sensitive to ether anesthesia (Gamo et al 1998). Furthermore, Calreticulin mutants exhibit impaired olfactory avoidance (Stoltzfus et al 2003;Sambandan et al 2006), yet respond normally to attractants (Stoltzfus et al 2003). Calreticulin transcripts also increase in sleepdeprived flies relative to flies in recovery sleep after sleep deprivation (Williams et al 2007).…”

“…Other mutant alleles of Calreticulin tested in flies are not null mutations (Gamo et al 1998;Stoltzfus et al 2003); indeed, it may not be possible to create a Calreticulin null mutation in flies as homozygous Calreticulin null mice die in the early embryonic stages (Mesaeli et al 1999). Future studies will determine what role Calreticulin has in sleep and waking.…”