Two distinct genomic regions, harbouring the period and fruitless genes, affect male courtship song in Drosophila montana

Acoustic signals often play a significant role in pair formation and in species recognition. Determining the genetic basis of signal divergence will help to understand signal evolution by sexual selection and its role in the speciation process. An earlier study investigated QTL for male courtship song carrier frequency in Drosophila montana using microsatellite markers. We refined this study by adding to the linkage map markers for ten candidate genes known to affect song production in D. melanogaster. We also extended the analyses to additional song characters (pulse train length, pulse number, interpulse interval, pulse length and cycle number). Our results indicate that loci in two different regions of the genome control distinct features of the courtship song. Pulse train traits (pulse train length and pulse number) mapped to the X chromosome, showing significant linkage with the period gene. In contrast, characters related to song pulse properties (pulse length, cycle number and ca...