The bees - we will never tire of emphasizing it - are extraordinary animals in terms of communication systems, pollination activities, collective intelligence of the colonies. A new study published in Biology Letters highlights another, perhaps less known, aspect of their exceptionality: that on their conception and on the genus of offspring, among the most "fluid" observed in the animal world.
In the Hymenoptera, the order of insects to which bees belong, the reproduction takes place in a slightly different way than we are used to. From the eggs that the queens lay without fertilizing, males will be born (which will therefore have only one set of chromosomes: that is, they are haploid); female worker bees usually arise from fertilized eggs. It is on this "normally" that we must understand each other.
An army of potential fathers. Females usually mate in flight with more than ten males (the "drones") at a time to repopulate the colony, and it happens that more than one spermatozoon fertilizes an egg. In some rare cases, the "daughters" bees can have part of female tissue derived from the fertilized egg, and part of the male tissue due to excess sperm: if an individual with both male and female organs is called hermaphrodite, those with characters either both masculine and feminine spread throughout the body are called ginandromorfi. This condition, although rare, is observed in insects, crustaceans and some birds.
Mixed results. Researchers at the University of Sydney (Australia) collected 11 ginandromorphic bees from a hive. After studying their physical characteristics, they analyzed their DNA to understand how they were generated. Ten of these individuals had up to three fathers. The latter had only fathers, and no maternal genetic inheritance: scientists think it may have been born from the fusion of the nuclei of two spermatozoa. If it were true it would be the first case of sperm fusion documented among Hymenoptera.
The important thing is to increase. Since ginandromorphism does not seem to be particularly advantageous, from the evolutionary point of view, the hypothesis is that such a large number within the same colony can be linked to some genetic mutation in the queen bee, although the study does not clarify which . Although this feature is not the norm, the study documents the incredible flexibility of social insects when it comes to reproduction.