|DONG, SHENGZHANG - University Of Missouri|
|ZHANG, HONGWEI - University Of Missouri|
|CHEN, XI - University Of Missouri|
|YU, XIAOPING - China Jiliang University|
|SONG, QISHENG - University Of Missouri|
Submitted to: Archives of Insect Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/16/2015
Publication Date: 3/27/2015
Citation: Dong, S., Zhang, H., Chen, X., Stanley, D.W., Yu, X., Song, Q. 2015. The neuropeptide bursicon acts in cuticle metabolism. Archives of Insect Biochemistry and Physiology. 89(2):87-97 doi: 10.1002/arch.21227.
Interpretive Summary: Application of classical insecticides has introduced severe problems into agricultural sustainability. The concept of biological control of insects is a potentially powerful alternative to classical insecticides. Biological control is based on the idea that direct application of insect-specific pathogens and parasites can reduce pest insect populations and the economic damage due to pest insects. The problem, however, is the efficiency of these organisms in biological control programs is limited by insect immune defense reactions to challenge. One approach to improving the efficiency of biocontrol agents would be to somehow disable insect cuticle (‘skin’) formation, to increase their vulnerability to viral, bacterial, fungal and parasitic infections. With this goal, we investigated cuticle formation in insect bodies. In this paper we report on identification of a hormone that acts in cuticle formation. This new research will be directly useful to scientists who are working to improve the efficacy of biological control methods. The ensuing improved biological control methods will benefit a wide range of agricultural producers by supporting the long-term sustainability of agriculture.
Technical Abstract: Bursicon is a heterodimeric neuropeptide formed of bursicon a (burs a) and bursicon B (burs B) that controls cuticle tanning and wing expansion in insects. Burs a-a and burs B-B homodimers are also formed; they act via an unknown receptor to induce expression of prophylactic immune and stress genes during molting. On the hypothesis that burs B-B and/or bursicon influence expression of additional genes acting after the molt, we prepared and sequenced six Drosophila cDNA libraries from groups of flies separately injected with burs B-B, bursicon, or blank control. Compared to the control, the burs B-B treatments led to up-regulation (by at least 1.5-fold) of 262 genes at 0.5 h post injection (PI) and 298 genes at 1 h PI; 323 genes at 0.5h PI and 269 genes at 1h PI were down-regulated (by at least 0.67). Similar changes were recorded following bursicon injections. Of these genes, expression of seven transcripts encoding cuticle proteins was up-regulated and three down-regulated by burs B-B; expression of nine transcripts encoding cuticle proteins were up-regulated and four down-regulated following bursicon treatments. Expression of dozens of genes involved in chitin metabolism was altered by the experimental treatments. We recorded parallel changes in expression of selected genes by transcriptome and qPCR analysis. These findings support our hypothesis that burs B-B and bursicon influence expression of additional genes acting after the molt. We report that burs B-B and bursicon act in cuticle synthesis and degradation by regulating the expression of cuticular protein- and chitin metabolizing-related genes.