The Potential Organ Involved in Cantharidin Biosynthesis in Epicauta chinensis Laporte (Coleoptera: Meloidae)

Abstract

Cantharidin, a terpenoid defensive toxin mainly produced by blister beetles, is among the most widely known insect natural products in the world. However, little is known about the site of cantharidin biosynthesis in vivo. Our previous research showed that 3-hydroxy-3-methylglutary-CoA reductase (HMGR) is an essential enzyme in cantharidin biosynthesis. In this report, we further investigated cantharidin titer and HMGR mRNA expression levels in different tissues of male and female Epicauta chinensis, and performed a comparative analysis of HMGR transcript levels in male Tenebrio molitor, a Tenebrionidae beetle that cannot produce cantharidin. HMGR transcripts had a positive correlation with cantharidin production. Furthermore, the specifically high amounts of HMGR transcript and abundant cantharidin production in fat body of male E. chinensis indicated the process of cantharidin synthesis may occur in the fat body.

Cantharidin content in two Mediterranean species of blister beetles, Lydus trimaculatus and Mylabris variabilis (Coleoptera: Meloidae)

“…; Jiang et al . ). However, the lack of a significant difference between sexes when comparing individuals randomly collected from the field could be due to the CA transfer by males to females during copulation, which would increase the total CA reserve in mated females (Sierra et al .…”

“…The slightly higher amount of CA in males might support the higher performance of males in producing and storing CA in dedicated tissues (e.g. the male accessory glands; Jiang et al 2017). However, the lack of a significant difference between sexes when comparing individuals randomly collected from the field could be due to the CA transfer by males to females during copulation, which would increase the total CA reserve in mated females (Sierra et al 1976;Nikbakhtzadeh et al 2012).…”

Drug Discovery Insights from Medicinal Beetles in Traditional Chinese Medicine

“…Cantharidin is extremely toxic to humans and livestock when ingested and can cause death due to hemorrhage of the gastrointestinal and urinary tracts, among other dangerous symptoms ( Schmitz, 1989 ; Karras et al ., 1996 ). Recently, there have been several studies investigating the biosynthetic genes and tissues responsible for cantharidin production in Epicauta ( Jiang et al ., 2017a , 2017b , 2019 ).…”

Anticancer Attributes of Cantharidin: Involved Molecular Mechanisms and Pathways

“…Insects of the meloid family beget CTD as a defensive vesicant against predators. It also plays a significant role in mating as male beetles produce it as sexual attractant which is later transferred to female beetles during copulation [ 21 , 22 ]. Although it is only produced by male beetles, its concentration remains 5–6% higher in some female species [ 23 ].…”