Juvenile hormone regulation of HMG-R gene expression in the bark beetle Ips paraconfusus (Coleoptera: Scolytidae): implications for male aggregation pheromone biosynthesis

1999 ◽  
Vol 55 (1) ◽  
pp. 121-127 ◽  
Author(s):  
C. Tittiger ◽  
G. J. Blomquist ◽  
P. Ivarsson ◽  
C. E. Borgeson ◽  
S. J. Seybold
Keyword(s):  
Gene Expression ◽  
Juvenile Hormone ◽  
Bark Beetle ◽  
Aggregation Pheromone ◽  
Ips Paraconfusus ◽  
Pheromone Biosynthesis ◽  
Hormone Regulation ◽  
R Gene ◽  
Male Aggregation

scholarly journals Host-Tree Monoterpenes and Biosynthesis of Aggregation Pheromones in the Bark BeetleIps paraconfusus

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
John A. Byers ◽  
Göran Birgersson
Keyword(s):  
Aggregation Pheromone ◽  
Pinus Ponderosa ◽  
Bark Beetles ◽  
De Novo ◽  
Host Tree ◽  
Ips Paraconfusus ◽  
Pheromone Biosynthesis ◽  
Host Plant Selection ◽  
Aggregation Pheromones ◽  
Host Trees

A paradigm developed in the 1970s thatIpsbark beetles biosynthesize their aggregation pheromone components ipsenol and ipsdienol by hydroxylating myrcene, a host tree monoterpene. Similarly, hostα-pinene was hydroxylated to a third pheromone componentcis-verbenol. In 1990, however, we reported that amounts of ipsenol and ipsdienol produced by maleIps paraconfusus(Coleoptera: Scolytinae) feeding in five host pine species were nearly the same, even though no detectable myrcene precursor was detected in one of these pines (Pinus sabiniana). Subsequent research showed ipsenol and ipsdienol are also biosynthesized from smaller precursors such as acetate and mevalonate, and thisde novopathway is the major one, while host tree myrcene conversion by the beetle is the minor one. We report concentrations of myrcene,α-pinene and other major monoterpenes in five pine hosts (Pinus ponderosa,P. lambertiana,P. jeffreyi,P. sabiniana, andP. contorta) ofI. paraconfusus. A scheme for biosynthesis of ipsdienol and ipsenol from myrcene and possible metabolites such as ipsenone is presented. Mass spectra and quantities of ipsenone are reported and its possible role in biosynthesis of aggregation pheromone. Coevolution of bark beetles and host trees is discussed in relation to pheromone biosynthesis, host plant selection/suitability, and plant resistance.

Disruption of red turpentine beetle attraction to baited traps by the addition of California fivespined ips pheromone components

2005 ◽  
Vol 137 (6) ◽  
pp. 748-752 ◽  
Author(s):  
Christopher J. Fettig ◽  
Robert R. Borys ◽  
Christopher P. Dabney ◽  
Stephen R. McKelvey ◽  
Daniel R. Cluck ◽  
...  
Keyword(s):  
North America ◽  
Bark Beetle ◽  
Aggregation Pheromone ◽  
Ips Paraconfusus ◽  
Management Tool ◽  
Beetle Species ◽  
Baited Traps ◽  
Pheromone Components ◽  
Temnochila Chlorodia ◽  
Cut Stumps

AbstractThe red turpentine beetle, Dendroctonus valens LeConte (Coleoptera: Scolytidae), is a common bark beetle species found throughout much of North America. In California, D. valens and the California fivespined ips, Ips paraconfusus Lanier (Coleoptera: Scolytidae), are sympatric and often colonize the same tree. In an unrelated study, we observed that I. paraconfusus attack densities in logging debris were inversely related to D. valens attacks on freshly cut stumps. In this study, we test the hypothesis that allomonal inhibition occurs between these two species. Components of the aggregation pheromone of I. paraconfusus (racemic ipsenol, (+)-ipsdienol, and (–)-cis-verbenol) inhibited the response of D. valens to attractant-baited traps. Substitution of racemic ipsdienol for (+)-ipsdienol did not alter this effect. Doubling the release rate did not enhance inhibition. Racemic ipsdienol was not attractive to I. paraconfusus. Temnochila chlorodia (Mannerheim, 1843) (Coleoptera: Trogositidae), a common bark beetle predator, was attracted to the I. paraconfusus aggregation pheromone. These results could have important implications for the development of an effective semiochemical-based management tool for D. valens.

Regulation of ACTH-R gene expression by CREB, CREMt and ICER in the adrenocortical cell line Y1

2005 ◽  
Vol 113 (S 1) ◽  
Author(s):  
O Zwermann ◽  
A Braun ◽  
E Lalli ◽  
F Beuschlein ◽  
M Reincke
Keyword(s):  
Gene Expression ◽  
Cell Line ◽  
R Gene ◽  
Adrenocortical Cell

scholarly journals Transcriptome analyses and virus induced gene silencing identify genes in the Rpp4-mediated Asian soybean rust resistance pathway

2013 ◽  
Vol 40 (10) ◽  
pp. 1029 ◽  
Author(s):  
Aguida M. A. P. Morales ◽  
Jamie A. O'Rourke ◽  
Martijn van de Mortel ◽  
Katherine T. Scheider ◽  
Timothy J. Bancroft ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Gene Silencing ◽  
Differentially Expressed ◽  
Soybean Rust ◽  
Phakopsora Pachyrhizi ◽  
R Gene ◽  
Virus Induced Gene Silencing ◽  
Asian Soybean Rust ◽  
Defence Responses

Rpp4 (Resistance to Phakopsora pachyrhizi 4) confers resistance to Phakopsora pachyrhizi Sydow, the causal agent of Asian soybean rust (ASR). By combining expression profiling and virus induced gene silencing (VIGS), we are developing a genetic framework for Rpp4-mediated resistance. We measured gene expression in mock-inoculated and P. pachyrhizi-infected leaves of resistant soybean accession PI459025B (Rpp4) and the susceptible cultivar (Williams 82) across a 12-day time course. Unexpectedly, two biphasic responses were identified. In the incompatible reaction, genes induced at 12 h after infection (hai) were not differentially expressed at 24 hai, but were induced at 72 hai. In contrast, genes repressed at 12 hai were not differentially expressed from 24 to 144 hai, but were repressed 216 hai and later. To differentiate between basal and resistance-gene (R-gene) mediated defence responses, we compared gene expression in Rpp4-silenced and empty vector-treated PI459025B plants 14 days after infection (dai) with P. pachyrhizi. This identified genes, including transcription factors, whose differential expression is dependent upon Rpp4. To identify differentially expressed genes conserved across multiple P. pachyrhizi resistance pathways, Rpp4 expression datasets were compared with microarray data previously generated for Rpp2 and Rpp3-mediated defence responses. Fourteen transcription factors common to all resistant and susceptible responses were identified, as well as fourteen transcription factors unique to R-gene-mediated resistance responses. These genes are targets for future P. pachyrhizi resistance research.

Increased tachykinin receptor gene expression in asthmatic lung and its modulation by steroids

1993 ◽  
Vol 11 (1) ◽  
pp. 1-7 ◽  
Author(s):  
I M Adcock ◽  
M Peters ◽  
C Gelder ◽  
H Shirasaki ◽  
C R Brown ◽  
...  
Keyword(s):  
Gene Expression ◽  
Chronic Inflammation ◽  
Northern Blot Analysis ◽  
Receptor Gene ◽  
Sensory Nerves ◽  
R Gene ◽  
Dexamethasone Treatment ◽  
Tachykinin Receptor ◽  
Neurokinin 1 ◽  
Receptor Gene Expression

ABSTRACT Substance P has several inflammatory effects on the airways mediated via neurokinin 1 receptors (NK1Rs) and, if released from sensory nerves, may amplify the chronic inflammation seen in asthma. Northern blot analysis of NK1R mRNA in lung showed a 52 ± 10% (s.e.m.; P<0·01) increase in mRNA in the asthmatic lung compared with non-asthmatic control tissue. NK1R mRNA was reduced by 84·5 ± 1·9% after incubation with dexamethasone (1 μm) for 3 h (P<0·01). In contrast, NK2R mRNA was unaltered in asthmatic lungs and dexamethasone treatment had no effect on the level of NK2R mRNA. These results suggest that chronic inflammation in asthma may result in increased NK1R gene expression and that this effect is reversed by glucocorticosteroids.

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