Location: Commodity Utilization Research
Title: Lactate accumulation in insects resulting from food-chain analysis of host plant-predator Authors
|Uchimiya, Hirofumi -|
|Kawai-Yamada, Maki -|
|Ojima, Noriyuki -|
|Suzuki, Koichi -|
|Miyagi, Atsuko -|
Submitted to: Metabolomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 3, 2013
Publication Date: N/A
Interpretive Summary: A large number of studies investigated the identity and quantity of biochemicals produced by plants and insects. However, little information is available to understand how biochemicals produced by host plant impacts that of predator insect, and vise versa. This study separately measured biochemicals produced by (1) leaf beetle at different developmental stages and (2) host plant, broad-leaved dock. The host plant uniquely accumulated a metabolite called oxalate that is toxic to the insect. In adult beetle, however, minimal amount of oxalate was found. In addition, larva of insects accumulated a key biochemical called lactate to produce necessary energy for growth. Rigorous statistical analyses of metabolites suggested the presence of pyruvate-lactate biosynthetic pathway in the studied insect. Existence of this vertebrate-type metabolic pathway in insects has a significant implication to the evolutional history that separated vertebrate from invertebrate (insects) a billion years ago.
Technical Abstract: Evolution has shown the co-dependency of host plants-predators (insects), especially inevitable dependency of predators on plant biomass for securing their energy sources. In this respect, it had been believed that NAD+ source used for major energy producing pathway in insects is a glycerol-3-phosphate shuttle (Zebe and McShen, 1957). Using high throughput metabolomics approach, we found that insect larva including beetle and butterfly possessed a unique mechanism for accumulating unusually high amounts of lactate. The evidence that insects possess the same vertebrate-type energy production pathway would provide new insight into the evolutional lineage of metabolic pathway in higher organism, which is believed to be separated more than a billion years ago.