@article{groot_schöfl_inglis_donnerhacke_classen_schmalz_santangelo_emerson_gould_schal_et al._2014, title={Within-population variability in a moth sex pheromone blend: genetic basis and behavioural consequences}, volume={281}, ISSN={0962-8452 1471-2954}, url={http://dx.doi.org/10.1098/rspb.2013.3054}, DOI={10.1098/rspb.2013.3054}, abstractNote={Evolutionary diversification of sexual communication systems in moths is perplexing because signal and response are under stabilizing selection in many species, and this is expected to constrain evolutionary change. In the moth Heliothis virescens, we consistently found high phenotypic variability in the female sex pheromone blend within each of four geographically distant populations. Here, we assess the heritability, genetic basis and behavioural consequences of this variation. Artificial selection with field-collected moths dramatically increased the relative amount of the saturated compound 16:Ald and decreased its unsaturated counterpart Z11-16:Ald, the major sex pheromone component (high line). In a cross between the high- and low-selected lines, one quantitative trait locus (QTL) explained 11-21% of the phenotypic variance in the 16:Ald/Z11-16:Ald ratio. Because changes in activity of desaturase enzymes could affect this ratio, we measured their expression levels in pheromone glands and mapped desaturase genes onto our linkage map. A delta-11-desaturase had lower expression in females producing less Z11-16:Ald; however, this gene mapped to a different chromosome than the QTL. A model in which the QTL is a trans-acting repressor of delta-11 desaturase expression explains many features of the data. Selection favouring heterozygotes which produce more unsaturated components could maintain a polymorphism at this locus.}, number={1779}, journal={Proceedings of the Royal Society B: Biological Sciences}, publisher={The Royal Society}, author={Groot, Astrid T. and Schöfl, Gerhard and Inglis, Ollie and Donnerhacke, Susanne and Classen, Alice and Schmalz, Antje and Santangelo, Richard G. and Emerson, Jennifer and Gould, Fred and Schal, Coby and et al.}, year={2014}, month={Mar}, pages={20133054} }
 @article{groot_staudacher_barthel_inglis_schöfl_santangelo_gebauer‐jung_vogel_emerson_schal_et al._2013, title={One quantitative trait locus for intra‐ and interspecific variation in a sex pheromone}, volume={22}, ISSN={0962-1083 1365-294X}, url={http://dx.doi.org/10.1111/mec.12171}, DOI={10.1111/mec.12171}, abstractNote={Abstract Even though premating isolation is hypothesized to be a major driving force in speciation, its genetic basis is poorly known. In the noctuid moth Heliothis subflexa, one group of sex pheromone components, the acetates, emitted by the female, plays a crucial isolating role in preventing interspecific matings to males of the closely related Heliothis virescens , in which females do not produce acetates and males are repelled by them. We previously found intraspecific variation in acetates in H. subflexa : females in eastern N orth A merica contain significantly more acetates than females in W estern M exico. Here we describe the persistence of this intraspecific variation in laboratory‐reared strains and the identification of one major quantitative trait locus ( QTL ), explaining 40% of the variance in acetate amounts. We homologized this intraspecific QTL to our previously identified interspecific QTL using restriction‐associated DNA ( RAD ) tags. We found that a major intraspecific QTL overlaps with one of the two major interspecific QTL . To identify candidate genes underlying the acetate variation, we investigated a number of gene families with known or suspected acetyl‐ or acyltransferase activity. The most likely candidate genes did not map to our QTL , so that we currently hypothesize that a transcription factor underlies this QTL . Finding a single, large QTL that impacts variation in pheromone blends between and within species is, to our knowledge, the first such example for traits that have been demonstrated to affect premating isolation.}, number={4}, journal={Molecular Ecology}, publisher={Wiley}, author={Groot, A. T. and Staudacher, H. and Barthel, A. and Inglis, O. and Schöfl, G. and Santangelo, R. G. and Gebauer‐Jung, S. and Vogel, H. and Emerson, J. and Schal, C. and et al.}, year={2013}, month={Jan}, pages={1065–1080} }
 @article{gould_estock_hillier_powell_groot_ward_emerson_schal_vickers_2010, title={Sexual isolation of male moths explained by a single pheromone response QTL containing four receptor genes}, volume={107}, ISSN={["0027-8424"]}, DOI={10.1073/pnas.0910945107}, abstractNote={Long distance sexual communication in moths has fascinated biologists because of the complex, precise female pheromone signals and the extreme sensitivity of males to specific pheromone molecules. Progress has been made in identifying some genes involved in female pheromone production and in male response. However, we have lacked information on the genetic changes involved in evolutionary diversification of these mate-finding mechanisms that is critical to understanding speciation in moths and other taxa. We used a combined quantitative trait locus (QTL) and candidate gene approach to determine the genetic architecture of sexual isolation in males of two congeneric moths, Heliothis subflexa and Heliothis virescens . We report behavioral and neurophysiological evidence that differential male responses to three female-produced chemicals ( Z 9-14:Ald, Z 9-16:Ald, Z 11-16:OAc) that maintain sexual isolation of these species are all controlled by a single QTL containing at least four odorant receptor genes. It is not surprising that pheromone receptor differences could control H. subflexa and H. virescens responses to Z 9-16:Ald and Z 9-14:Ald, respectively. However, central rather than peripheral level control over the positive and negative responses of H. subflexa and H. virescens to Z 11-16:OAc had been expected. Tight linkage of these receptor genes indicates that mutations altering male response to complex blends could be maintained in linkage disequilibrium and could affect the speciation process. Other candidate genes such as those coding for pheromone binding proteins did not map to this QTL, but there was some genetic evidence of a QTL for response to Z 11-16:OH associated with a sensory neuron membrane protein gene.}, number={19}, journal={PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA}, author={Gould, Fred and Estock, Marie and Hillier, N. Kirk and Powell, Bekah and Groot, Astrid T. and Ward, Catherine M. and Emerson, Jennifer L. and Schal, Coby and Vickers, Neil J.}, year={2010}, month={May}, pages={8660–8665} }
 @article{emerson_frampton_mckeand_2008, title={Genetic variation in early growth and bud production among natural populations of fraser fir}, volume={43}, number={3}, journal={HortScience}, author={Emerson, J. L. and Frampton, J. and McKeand, S. E.}, year={2008}, pages={661–666} }
 @article{emerson_frampton_mckeand_2006, title={Genetic variation of spring frost damage in 3-year-old Fraser fir Christmas tree plantations}, volume={41}, number={7}, journal={HortScience}, author={Emerson, J. L. and Frampton, J. and McKeand, S. E.}, year={2006}, pages={1531–1536} }
 @inproceedings{emerson_frampton_mckeand_2005, title={Genetic variation in young Fraser fir progeny tests}, booktitle={Proceedings of the 28th Southern Forest Tree Improvement Conference}, author={Emerson, J. L. and Frampton, L. J. and McKeand, S. E.}, year={2005}, pages={115–117} }