Genetics. Published Articles Ahead of Print: June 18, 2008, Copyright © 2008
doi:10.1534/genetics.108.088435


A more recent version of this article appeared on July 1, 2008.


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Pleiotropic Effects of Drosophila neuralized on Complex Behaviors and Brain Structure

1 North Carolina State University
2 Katholieke Universiteit Leuven

* To whom correspondence should be addressed. E-mail: anholt{at}ncsu.edu.

Submitted on February 23, 2008
Revised on April 17, 2008
Accepted on 24 April 2008


Abstract

Understanding how genotypic variation influences variation in brain structures and behavioral phenotypes represents a central challenge in behavioral genetics. In Drosophila melanogaster, the neuralized (neur) gene plays a key role in development of the nervous system. Different P-element insertional mutations of neur allow the development of viable and fertile adults with profoundly altered behavioral phenotypes that depend on the exact location of the inserted P-element. The neur mutants exhibit reduced responsiveness to noxious olfactory and mechanosensory stimulation and increased aggression when limited food is presented after a period of food deprivation. These behavioral phenotypes are correlated with distinct structural changes in integrative centers in the brain, the mushroom bodies and ellipsoid body of the central complex. Transcriptional profiling of neur mutants revealed considerable overlap among ensembles of co-regulated genes in the different mutants, but also distinct allele-specific differences. The diverse phenotypic effects arising from nearby P-element insertions in neur provide a new appreciation of the concept of allelic effects on phenotype, in which the wild type and null mutant are at the extreme ends of a continuum of pleiotropic allelic effects.

Key Words: P-element mutagenesis, aggression, locomotor reactivity, olfaction, transcriptional profiling