Natures wonders: beewolf egg uses nitric oxide (Introduction)

by David Turell , Tuesday, June 11, 2019, 19:33 (1990 days ago) @ David Turell

The eggs produce nitric oxide to preserve food supply for larvae:

https://phys.org/news/2019-06-beewolves-gas-food.html

"Scientists from the Universities of Regensburg and Mainz and the Max Planck Institute for Chemical Ecology discovered that the eggs of the European beewolf produce nitric oxide. The gas prevents the larvae's food from getting moldy in the warm and humid brood cells.

***

"The European beewolf Philanthus triangulum, a solitary wasp species whose females hunt honey bees, has evolved a successful method of food preservation. A female takes up to five honey bees into its brood cells where they serve as food for a young beewolf. Female beewolves prefer to build their nests in sunlit and sandy places. The nests are deep and therefore the brood cells are warm and humid. Such conditions are favorable for the development of the beewolf larvae; however, they also foster the growth of mold fungi. As a matter of fact, bees stored under such conditions in the lab were overgrown by mold within one to three days. Surprisingly, the mold risk for bees was much lower in the nests of beewolves, so that most beewolf larvae were able to finish their eight to ten-day development until they spin a cocoon.

***

"Bioassays showed that beewolf eggs emit a gas that efficiently kills mold fungi. A chemical analysis revealed the surprising result that the gas is nitric oxide (NO). The eggs produce nitric oxide in large quantities and release it to the air where is reacts with atmospheric oxygen to nitrogen dioxide (NO2). The measured NO2 concentrations in the brood cells exceed both the occupational exposure limits of NO and NO2 as well as the EU maximum permissible values in cities.

***

"Although beewolf eggs produce enormous amounts of NO, they use the same enzymes, NO synthases, which are also used by other organisms. Also, the responsible NO synthase gene in beewolves does not have any special characteristics. However, the researchers found a modification in the translation of the gene into the protein, which may be responsible for the unusually high synthesis rate of NO in beewolf eggs. "Due to so-called alternative splicing the enzyme in the beewolf eggs lacks a segment which may be responsible for regulation.

***

The most amazing aspect of the defense strategy of beewolf eggs is the fact that the eggs are obviously able to survive the extremely toxic conditions they produce themselves. Which mechanism the eggs deploy is the subject of current investigations. (my bold)

Comment: The bolded paragraph points out a key issue. The ability to produce nitric oxide had to develop at the same time as a protective mechanism was provided. Otherwise the eggs would not have survived. This can only originate by design, not by stepwise development.