@article{sheck_groot_ward_gemeno_wang_brownie_schal_gould_2006, title={Genetics of sex pheromone blend differences between Heliothis virescens and Heliothis subflexa: a chromosome mapping approach}, volume={19}, ISSN={["1420-9101"]}, DOI={10.1111/j.1420-9101.2005.00999.x}, abstractNote={Abstract Males of the noctuid moths, Heliothis virescens and H. subflexa locate mates based on species‐specific responses to female‐emitted pheromones that are composed of distinct blends of volatile compounds. We conducted genetic crosses between these two species and used AFLP marker‐based mapping of backcross families ( H. subflexa direction) to determine which of the 30 autosomes in these moths contained quantitative trait loci (QTL) controlling the proportion of specific chemical components in the pheromone blends. Presence/absence of single H. virescens chromosomes accounted for 7–34% of the phenotypic variation among backcross females in seven pheromone components. For a set of three similar 16‐carbon acetates, two H. virescens chromosomes interacted in determining their relative amounts within the pheromone gland and together accounted for 53% of the phenotypic variance. Our results are discussed relative to theories about population genetic processes and biochemical mechanisms involved in the evolution of new sexual communication systems.}, number={2}, journal={JOURNAL OF EVOLUTIONARY BIOLOGY}, author={Sheck, AL and Groot, AT and Ward, CM and Gemeno, C and Wang, J and Brownie, C and Schal, C and Gould, F}, year={2006}, month={Mar}, pages={600–617} }
 @article{groot_ward_wang_pokrzywa_o’brien_bennett_kelly_santangelo_schal_gould_2004, title={Introgressing pheromone QTL between species: Towards an evolutionary understanding of differentiation in sexual communication}, volume={30}, ISSN={["1573-1561"]}, DOI={10.1007/s10886-004-7946-y}, abstractNote={As a first step toward understanding how noctuid moths evolve species-specific pheromone communication systems, we hybridized and backcrossed two closely related moth species, Heliothis virescens (Hv) and H. subflexa (Hs), which differ qualitatively and quantitatively in their multi-component sex pheromone blends. We used amplified fragment length polymorphism (AFLP) marker-based mapping of backcross families to determine which of the 30 autosomes in these moths contained quantitative trait loci (QTL) controlling the percentages of specific chemical components in the pheromone blends. In two previous backcrosses to Hs, we found a strong depressive effect of Hv-chromosome 22 on the percentage of three acetate components in the pheromone gland. These acetates are present in Hs and absent in Hv. Here, we describe how we introgressed Hv-chromosome 22 into the genomic background of Hs. Selection for Hv-chromosome 22 started from backcross 3 (BC3) females. All females that had Hv-chromosome 22 and a low percentage of acetates (< 3% of the total amount of pheromone components present) were backcrossed to Hs males. In BC5 to BC8, we determined whether Hv-chromosome 22 was present by a) running only the primer pairs that would yield the markers for that chromosome, and/or b) determining the relative percentages of acetates in the pheromone glands. Either or both genotype and phenotype were used as a criterion to continue to backcross these females to Hs males. In BC9, we confirmed the isolation of Hv-chromosome 22 in the Hs genomic background, and backcrossed the males to Hs females to eliminate the Hv-sex chromosome as well as mitochondrial DNA. The pheromone composition was determined in BC3, BC5, and BC11 females with and without Hv-chromosome 22. All backcross females with Hv-chromosome 22 contained significantly less acetates than females without this chromosome. In addition, BC3 females with Hv-chromosome 22 contained significantly more Z11-16:OH than BC3 females without Hv-chromosome 22. However, in BC5 and BC11 females, the correlation between Z11-16:OH and Hv-chromosome 22 was lost, suggesting that there are separate QTL for the acetates and for Z11-16:OH, and that the relative amount of the alcohol component is only affected in epistasis with other (minor) QTL. Now that we have succeeded in isolating the chromosome that has a major effect on acetate production, we can test in behavioral experiments whether the presence of acetates may have been a driving force for a shift in pheromone composition. Such tests are necessary to move towards an evolutionary understanding of the differentiation in sexual communication in Heliothis spp. moths.}, number={12}, journal={Journal of Chemical Ecology}, author={Groot, A.T. and Ward, C. and Wang, J. and Pokrzywa, A. and O’Brien, J. and Bennett, J. and Kelly, J. and Santangelo, R.G. and Schal, C. and Gould, F.}, year={2004}, pages={2495–2514} }