Combining Genome-Wide Methods to Investigate the Genetic Complexity of Courtship Song Variation in Drosophila melanogaster

Abstract

Little is currently known about the genetic complexity of quantitative behavioral variation, the types of genes involved, or their effects on intermediate phenotypes. Here, we conduct a genome-wide association study of Drosophila melanogaster courtship song variation using 168 sequenced inbred lines, and fail to find highly significant associations. However, by combining these data with results from a well-powered Evolve and Resequence (E&R) study on the same trait, we provide statistical evidence that some power to associate genotype and phenotype is available. Genes that are significant in both analyses are enriched for expression in the nervous system, and affect neural development and synaptic growth when perturbed. Quantitative complementation at one of these loci, Syntrophin-like 1, supports a hypothesis that variation at this locus affects variation in the inter-pulse interval of courtship song. These results suggest that experimental evolution may provide an approach for genome-scale replication in Drosophila.

Host adaptation to viruses relies on few genes with different cross-resistance properties

“…Thus far, only a weak but significant correlation has been found between SNPs associated with polygenic traits by GWAS and evolve-and-resequence (E&R) approaches (31). Here, we confirm pst, a gene found through a GWAS approach (21), as a central player in the adaptation of an outbred population of Drosophila to DCV infection.…”

“…These results confirm the power of the E&R approach in the identification of targets of selection (32). This methodology has been used to identify changes in allele frequencies following selection in complex traits such as developmental time (7), body size (8), hypoxia tolerance (6), increased life span (33), adaptation to high/low temperatures (9,34), and courtship behavior (10,31). These studies have identified a polygenic basis for the studied traits, hampering the identification of candidate genes and a subsequent functional analysis.…”

Fine-Mapping Nicotine Resistance Loci inDrosophilaUsing a Multiparent Advanced Generation Inter-Cross Population

“…Resolving the actual causative loci underlying our QTL might also be achieved by carrying out a genome-wide association study (GWAS) using a panel of naturally derived inbred genotypes (Mackay et al 2012), by comparing allele frequency variation between pools of susceptible and resistant genotypes (Lai et al 2007;Huang et al 2012, Bastide et al 2013 or by measuring allele frequency divergence in divergently selected populations (Burke et al 2010;Turner et al 2011Turner et al , 2013. Often these studies are complicated by the very conservative statistical thresholds that must be employed to avoid false positives.…”

Combining linkage and association mapping identifiesRECEPTOR-LIKE PROTEIN KINASE1as an essentialArabidopsisshoot regeneration gene

“…Because the potential dominance of poor regeneration alleles in Ga-0 might interfere with a transgenic complementation approach, we opted for quantitative complementation to validate RPK1 as the most likely gene underlying REG-1. This method is well-established in natural variation studies in animal systems (37)(38)(39) and has successfully been applied in plant research as well (40,41). We crossed the parental accessions Nok-3 and Ga-0 to the WT Col-0 and the rpk1-5 mutant and analyzed the regeneration rate of the four resulting F1 genotypes.…”