Researchers Recently Documented The First Ever Case Of A Motherless Honey Bee With Two Fathers
Honey bee reproduction is very different from mammalian reproduction. Humans and other mammals possess cells with two sets of chromosomes, making most mammals diploid organisms. Honey bees, on the other hand, are categorized as haplodiploid. This is because queen honey bees possess two chromosomes per cell while drones have only one chromosome per cell. This means that the exclusively male drones only develop from eggs that were not fertilized by sperm. Female worker bees are born from eggs that were fertilized with male sperm, making them diploid organisms. However, in one to two percent of cases, sex-mixed honey bee offspring can develop. These mixed-sex bees are known as “gynandromorphs” and they develop from many cell lines of different origin and different sex.
While scientists know that gynandromorph honey bees develop from genetic mutations, it is not clear why and how these mutations occur. In an effort to better understand how gynandromorph bees develop, researchers collected gynandromorphs from one single colony before analyzing the DNA contained within tissue samples taken from different areas of each specimen’s body. The DNA showed that these mixed sex bees had three or four parents, most of which had either two or three fathers to the one queen mother. This was expected, but what was not expected were the bees that proved to originate from two fathers only. This is the first recorded case of a motherless bee with two fathers.
When it comes to mammalian reproduction, only one sperm can enter an egg. This is because a chemical reaction occurs within the egg that prevents more than one sperm from entering. But honey bees can develop from two sperm that fuse to an egg. This phenomena is known as “polyspermy,” and this is probably how gynandromorph honey bees develop. However, no research publication has ever described a honey bee born from the fusion of two sperm. Until the discovery of the motherless bee with two fathers, it was thought impossible for two sperm to fuse to create offspring, but the results of this recent study suggest that this was how the unique and extremely rare motherless bee offspring developed.
Have you ever heard of any other insect species in which offspring can develop from the fusion of two sperm within a female egg that does not contain a nucleus?