The pinyon ips beetle, Ips confusus (LeConte) is a highly destructive pest in pine forests in western North America. When colonizing a new host tree, I. confusus beetles coordinate a mass attack to overcome the tree's defenses using aggregation pheromones. Ips confusus, as with other Ips spp. beetles, biosynthesize ipsdienol and ipsenol in a specific enantiomeric blend and ratio as aggregation pheromones. While several of the initial steps in the pheromone biosynthetic pathway have been well defined, the final steps were unknown. We used comparative RNA-Seq analysis between fed and unfed male I. confusus midgut tissue to identify candidate genes involved in pheromone biosynthesis. The 12,995 potentially unique transcripts showed a clear separation based on feeding state. Differential expression analysis identified gene groups that were tightly connected. This analysis identified all known pheromone biosynthetic genes and suggested a novel monoterpene double bond reductase, ipsdienone reductase (IDONER), with pheromone biosynthetic gene expression patterns. IDONER cDNA was cloned, expressed, and functionally characterized. The coding DNA sequence has an ORF of 1101 nt with a predicted translation product of 336 amino acids. The enzyme has a molecular weight of 36.7 kDa with conserved motifs of the medium chain dehydrogenases/reductase (MDR) superfamily in the leukotriene B4 dehydrogenases/reductases (LTB₄R) family. Tagged recombinant protein was expressed and purified. Enzyme assays and GC/MS analysis showed IDONER catalyzed the reduction of ipsdienone to form ipsenone. This study shows that IDONER is a monoterpene double bond reductase involved in I. confusus pheromone biosynthesis.

pinyon ips 甲虫，Ips confusus (LeConte) 是北美西部松树林中一种极具破坏性的害虫。当殖民一棵新的寄主树时，I. confusus甲虫使用聚集信息素协调大规模攻击以克服树的防御。Ips confusus，与其他Ips spp 一样。甲虫，以特定的对映体混合物和比例生物合成异丙二烯醇和异丙酚作为聚集信息素。虽然信息素生物合成途径中的几个初始步骤已明确定义，但最终步骤尚不清楚。我们在喂食和未喂食的雄性I. confusus之间使用了比较 RNA-Seq 分析中肠组织以识别参与信息素生物合成的候选基因。12,995 个潜在独特的转录本显示出基于进食状态的明显分离。差异表达分析确定了紧密连接的基因组。该分析确定了所有已知的信息素生物合成基因，并提出了一种新的单萜双键还原酶，异戊二烯酮还原酶 (IDONER)，具有信息素生物合成基因的表达模式。IDONER cDNA 被克隆、表达和功能表征。编码 DNA 序列的 ORF 为 1101 nt，预计翻译产物为 336 个氨基酸。该酶的分子量为 36.7 kDa，具有白三烯 B4 脱氢酶/还原酶 (LTB _{4 ) 中中链脱氢酶/还原酶 (MDR) 超家族的保守基序}R) 家庭。标记的重组蛋白被表达和纯化。酶测定和 GC/MS 分析表明，IDONER 催化异丙二烯酮还原形成异丙苯醌。本研究表明， IDONER是一种单萜双键还原酶，参与迷迭香信息素的生物合成。