Characterization and functional assay of a fatty acyl‐CoA reductase gene in the scale insect, Ericerus pela Chavannes (Hemiptera: Coccoidae)

Abstract

Ericerus pela Chavannes (Hemiptera: Coccoidae) is an economically important scale insect because the second instar males secrete a harvestable wax-like substance. In this study, we report the molecular cloning of a fatty acyl-CoA reductase gene (EpFAR) of E. pela. We predicted a 520-aa protein with the FAR family features from the deduced amino acid sequence. The EpFAR mRNA was expressed in five tested tissues, testis, alimentary canal, fat body, Malpighian tubules, and mostly in cuticle. The EpFAR protein was localized by immunofluorescence only in the wax glands and testis. EpFAR expression in High Five insect cells documented the recombinant EpFAR reduced 26-0:(S) CoA and to its corresponding alcohol. The data illuminate the molecular mechanism for fatty alcohol biosynthesis in a beneficial insect, E. pela.

Ten fatty acyl‐CoA reductase family genes were essential for the survival of the destructive rice pest, Nilaparvata lugens

“…EpFAR) are reported to be involved in cuticular wax biosynthesis. 7,8,10 Thus, we conclude that despite the high homology, the biological functions of FARs within groups are not conserved during insect evolution.…”

“…9 EpFAR, which was identified in the wax-producing Ericeru pela, was shown to be involved in wax biosynthesis by reducing acyl CoA to its corresponding alcohol. 8 In our previous study, we identified a FAR (NlFAR7) displaying a periodical expression peak in the integument of the brown planthopper Nilaparvata lugens after each molting. NlFAR7 is involved in the synthesis of CHCs and plays a crucial role in insect cuticle waterproofing.…”

“…7 Fatty alcohols are essential precursors of sex pheromones, wax esters and cuticular hydrocarbons (CHC) in insects. [8][9][10] BmFAR, the first insect FAR gene characterized in the silkworm Bombyx mori, is pheromone gland-specific and involved in pheromone biosynthesis. 10 Another pheromone gland-specific FAR (OsFARXIII) is responsible for the production of (Z)-11-tetradecenol in the adzuki bean borer Ostrinia scapulalis, which is converted to its acetate or aldehyde derivative pheromones.…”

“…Similarly, CHC deficiency in N. lugens resulted in increased adhesion of water droplets and secreted honeydew to the insect surface and the inability of N. lugens to survive in paddy fields with varying humidity. Knockdown of NlFAR1,4,5,6,8,9,11 and 13 additionally resulted in female adult infertility.CONCLUSION: The present study illustrates the structural and functional differences of FAR family genes and provides potential targets for RNA interference-based rice planthopper management.…”

Expansion of the fatty acyl reductase gene family shaped pheromone communication in Hymenoptera

“…While more than 20 FARs have been experimentally characterized from 23 moth and butterfly (Lepidoptera) species 25 , FARs from other insect orders have received far less attention. Single FAR genes have been isolated and experimentally characterized from Drosophila (Diptera) 14 , the European honeybee (Hymenoptera) 26 and the scale insect Ericeus pela (Hemiptera) 27 . Our limited knowledge about FAR function prevents us from drawing inferences about the biological significance of the FAR gene family expansion in insects.…”