Shocking discovery made by scientists about bacteria manipulating wasps to kill their males

Rod Shaped Bacteria (Representative Image - Canva)

Some groups of bacteria are known for killing males of a host species. The rod-shaped bacteria known as Arsenophonus nasoniae kills the parasitic wasp Nasonia vitripennis male eggs spread across European populations.

This bacteria infects both sexes of the parasite wasp but targets the males and kills around 70 % of them. A study conducted in the Netherlands and Germany by scientists revealed that two of the female Nasonia vitripennis wasps produce a high number of female-dominant sex ratios.

In German investigations, it was found that the wasp was infected with Arsenophonus nasoniae. A survey was conducted in 2012 to know the widespread presence of the infection in the wasps.

The collected fly pupal hosts of N. vitripennis for this survey got done that are present across four European populations. In the survey, the wasps were permitted to emerge from their pupae and were then tested for A. nasoniae bacteria presence in them through a process of PCR assays, or Polymerase Chain Reaction assays, which are laboratory techniques used to amplify and detect specific DNA sequences.

A. nasoniae has been found in N. vitripennis populations throughout Europe, including Germany, the United Kingdom, Finland, Switzerland, and Portugal. The widespread presence of A. nasoniae infection varied amongst samples, ranging from uncommon occurrences to 50% of the pupae parasitized by N. vitripennis.

Patrick Ferree, Cornell postdoctoral fellow in molecular biology and genetics explained in detail why only the males get killed, according to him the bacteria infect the female mother but not the egg he said,  "Arsenophonus resides in the tissues around the developing eggs in the infected mother but not in the egg itself, so the bacteria likely secrete an unknown substance that penetrates the eggs to affect embryonic development."

The centrosome is responsible for the development of the male population of the wasp, a crucial aspect of the development and segregation of chromosomes into new cells and the bacteria attack directly on the centrosome.

Only males are vulnerable to the bacteria due to the female Nasonia develops from eggs fertilized by sperm, and the female inherits both the mother and father centrosomes and sperm. On the other hand, the males develop from unfertilized eggs and only have centrosomes.

Arsenophonus has evolved to specifically destroy the egg-derived centrosomes, the male egg is more prone the failure in the development of embryos properly while the female remains unaffected.