@article {11288,
	title = {Antennally mediated negative feedback regulation of pheromone production in the pine engraver beetle, Ips pini},
	journal = {Naturwissenschaften},
	volume = {94},
	number = {1},
	year = {2007},
	month = {January},
	pages = {61-64},
	abstract = {Bark beetles use monoterpenoid aggregation pheromones to coordinate host colonization and mating. These chemical signals are produced de novo in midgut cells via the mevalonate pathway, and pheromone production may be regulated by a negative feedback system mediated through the antennae. In this study, we explored the effect of antennectomy on pheromone production and transcript levels of key mevalonate pathway genes in juvenile hormone III-treated male pine engraver beetles, Ips pini (Say). Antennectomized males produced significantly greater amounts of pheromone than podectomized males and those with intact antennae. Likewise, mRNA levels of three mevalonate pathway genes important in pheromone biosynthesis were measured by quantitative real-time PCR and found to be induced to a greater extent with antennectomy, suggesting a transcriptional regulation of pheromone production},
	keywords = {Ips pini},
	isbn = {0028-1042},
	author = {Ginzel, Matthew D. and Bearfield, Jeremy C. and Keeling, Christopher I. and McCormack, Colin C. and Blomquist, Gary J. and Tittiger, Claus}
}
@article {9241,
	title = {Two regulatory mechanisms of monoterpenoid pheromone production in Ips spp. of bark beetles},
	journal = {Journal of Chemical Ecology},
	volume = {35},
	number = {6},
	year = {2009},
	month = {June},
	pages = {689-697},
	abstract = {Bark beetles use aggregation pheromones to coordinate host colonization and mating. These monoterpenoid chemical signals are produced de novo in midgut cells via the mevalonate pathway, and pheromone production is induced when an adult beetle feeds on phloem of a host tree. In Ips pini, juvenile hormone (JH) III influences key regulatory enzymes along the mevalonate pathway that leads to pheromone production. In fact, topically applied JH III is sufficient to stimulate pheromone production in unfed males. In this study, we explore the influence of feeding and JH III treatment on pheromone production in male Ips confusus, the pinyon Ips. We also characterize the influence of feeding and JH III treatment on transcript levels and activity of three key enzymes involved in pheromone biosynthesis: 3-hydroxy-3-methylglutaryl-CoA (HMG) synthase (HMGS), HMG-CoA reductase (HMGR) and geranyl diphosphate synthase (GPPS). We also extend the current understanding of the regulation of pheromone biosynthesis in I. pini, by measuring the influence of feeding and JHIII treatment on enzymatic activity of HMGS and GPPS. Feeding on host phloem alone strongly induces pheromone production in male I. confusus, while JH III treatment has no effect. However, feeding and JH III both significantly up-regulate mRNA levels of key mevalonate pathway genes. Feeding up-regulates these genes to a maximum at 32 h, whereas with JH III-treatment, they are up-regulated at 4, 8, and 16 h, but return near to non-treatment levels at 32 h. Feeding, but not JH III treatment, also increases the activity of all three enzymes in I. confusus, while both feeding or treatment with JH III increase HMGS and GPPS activity in I. pini. Our data suggest that pheromone production in Ips is not uniformly controlled by JH III and feeding may stimulate the release of some other regulatory factor, perhaps a brain hormone, required for pheromone production.},
	keywords = {Ips, Ips pini},
	isbn = {0098-0331},
	author = {Bearfield, Jeremy C. and Henry, Anastasia G. and Tittiger, Claus and Blomquist, Gary J. and Ginzel, Matthew D.}
}
@article {5468,
	title = {Functional genomics of mountain pine beetle (Dendroctonus ponderosae) midguts and fat bodies},
	journal = {BMC Genomics},
	volume = {11},
	number = {215},
	year = {2010},
	month = {30 March},
	pages = {12pp.},
	abstract = {Background: The mountain pine beetle (Dendroctonus ponderosae) is a significant coniferous forest pest in western North America. It relies on aggregation pheromones to colonize hosts. Its three major pheromone components, trans-verbenol, exo-brevicomin, and frontalin, are thought to arise via different metabolic pathways, but the enzymes involved have not been identified or characterized. We produced ESTs from male and female midguts and associated fat bodies and used custom oligonucleotide microarrays to study gene expression patterns and thereby made preliminary identification of pheromone-biosynthetic genes. Results: Clones from two un-normalized cDNA libraries were directionally sequenced from the 5{\textquoteright} end to yield 11,775 ESTs following sequence cleansing. The average read length was 550 nt. The ESTs clustered into 1,201 contigs and 2,833 singlets (4,034 tentative unique genes). The ESTs are broadly distributed among GO functional groups, suggesting they reflect a broad spectrum of the transcriptome. Among the most represented genes are representatives of sugar-digesting enzymes and members of an apparently Scolytid-specific gene family of unknown function. Custom NimbleGen 4-plex arrays representing the 4,034 tentative unique genes were queried with RNA from eleven different biological states representing larvae, pupae, and midguts and associated fat bodies of unfed or fed adults. Quantitative (Real-Time) RT-PCR (qRT-PCR) experiments confirmed that the microarray data accurately reflect expression levels in the different samples. Candidate genes encoding enzymes involved in terminal steps of biosynthetic pathways for exo-brevicomin and frontalin were tentatively identified. Conclusions: These EST and microarray data are the first publicly-available functional genomics resources for this devastating forestry pest},
	keywords = {Dendroctonus ponderosae},
	isbn = {1471-2164},
	url = {http://www.biomedcentral.com/content/pdf/1471-2164-11-215.pdf},
	author = {Aw, Tidiane and Schlauch, Karen and Keeling, Christopher I. and Young, Sharon and Bearfield, Jeremy C. and Blomquist, Gary J. and Tittiger, Claus}
}
