title: Feeding-Related Traits Are Affected by Dosage of the foraging Gene in Drosophila melanogaster.
abstract: Nutrient acquisition and energy storage are critical parts of achieving metabolic homeostasis. The foraging gene in Drosophila melanogaster has previously been implicated in multiple feeding-related and metabolic traits. Before foraging's functions can be further dissected, we need a precise genetic null mutant to definitively map its amorphic phenotypes. We used homologous recombination to precisely delete foraging, generating the for0null allele, and used recombineering to reintegrate a full copy of the gene, generating the {forBAC} rescue allele. We show that a total loss of foraging expression in larvae results in reduced larval path length and food intake behavior, while conversely showing an increase in triglyceride levels. Furthermore, varying foraging gene dosage demonstrates a linear dose-response on these phenotypes in relation to foraging gene expression levels. These experiments have unequivocally proven a causal, dose-dependent relationship between the foraging gene and its pleiotropic influence on these feeding-related traits. Our analysis of foraging's transcription start sites, termination sites, and splicing patterns using rapid amplification of cDNA ends (RACE) and full-length cDNA sequencing, revealed four independent promoters, pr1-4, that produce 21 transcripts with nine distinct open reading frames (ORFs). The use of alternative promoters and alternative splicing at the foraging locus creates diversity and flexibility in the regulation of gene expression, and ultimately function. Future studies will exploit these genetic tools to precisely dissect the isoform- and tissue-specific requirements of foraging's functions and shed light on the genetic control of feeding-related traits involved in energy homeostasis.
authors.affiliation: Department of Cell and Systems Biology, University of Toronto, Ontario M5S 3G5, Canada.
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Allen
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Toronto, Ontario M5S 3B2, Canada.|Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario M5G 1Z8, Canada, and.
authors.forename: Ina
authors.initials: I
authors.lastname: Anreiter
authors.affiliation: Centre for Neural Circuits and Behaviour, University of Oxford, OX1 3SR Oxford, UK.
authors.forename: Megan C
authors.initials: MC
authors.lastname: Neville
authors.affiliation: Department of Cell and Systems Biology, University of Toronto, Ontario M5S 3G5, Canada marla.sokolowski@utoronto.ca.|Department of Ecology and Evolutionary Biology, University of Toronto, Ontario M5S 3B2, Canada.|Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario M5G 1Z8, Canada, and.
authors.forename: Marla B
authors.identifier: 0000-0002-7462-8007
authors.initials: MB
authors.lastname: Sokolowski
mesh_terms: D000818:Animals; D017869:Cyclic GMP-Dependent Protein Kinases / Q000235:genetics* / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D005247:Feeding Behavior; D018628:Gene Dosage; D058685:Genetic Pleiotropy; D010641:Phenotype; D011401:Promoter Regions, Genetic; D012326:RNA Splicing; D014280:Triglycerides / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D014280:Triglycerides; D017869:Cyclic GMP-Dependent Protein Kinases; C528566:for protein, Drosophila
keywords: behavior; fat; foraging gene; larva; null mutant