Weird! – that is the world of the honey bee!
The importance of genes is nothing new to most of us. You certainly have heard of the importance of genes, how a mother and father each contribute their important element, and so on. Today, we accept, without question, that the mother contributes chromosomes from her egg and the father from his sperm. Much of the animal kingdom operates with these principles.
But that is not the case with honey bees – bee genetics are downright weird!
The honey bees use an altogether different approach in passing chromosomes, with some strange implications. For example, consider these facts about the drones – male bee.
- They have no father
- They have a grandfather
- They can be fathers to daughters, granddaughters, and grandsons
- They can’t have sons
Confused? Read on…
Haplodipl0dy Phenomenon
The cause of all this weirdness is a sex-determination system called haplodiplody that occurs in some insects. Bees, along with many other insects, and all the Hymenoptera (bees, wasps, and ants) are haplodiploid organisms. Meaning sex is based on the number of chromosomes they receive.
Don’t go away yet; this isn’t difficult.
In the curious world of the honey bee, a male, the drone, is created from an unfertilized egg – just an egg laid by a Queen, without being fertilized by sperm. The male bee, the drone, is therefore referred to as a haploid.
The more familiar situation, where the Queen fertilizes an egg with sperm, results in a female bee. This means the egg is destined to be a worker bee or a Queen bee. Female honey bees are therefore referred to as diploids.
The Impact on Genes
So, what does all this mean in terms of the transfer of genes across generations? Let’s consider, as a baseline, how humans compare.
Our genes are contained in chromosomes. We receive 46 chromosomes – 23 from our mother and 23 from our father. The transfer of genes through the generations means the characteristics of both sides of our family are evident in us and represented by factors such as eye color, height, and so on. This is all because we result from an egg contributed by our mother and sperm contributed by our father.
The same basic principle exists with bees – but only in female bees.
Female bees are created when a queen lays an egg that she then fertilizes. Though the numbers are different with bees (as compared to humans), each side of the family contributes the same number of chromosomes (16).
It becomes a little stranger when we turn to the haploid – the drone. Male bees only include the chromosomes from the egg, since they have not been fertilized. Thus, drones have just 16 chromosomes, all from the Queen.
Watch this space for more on why the next time you are inspecting your bees should you note a large presence of drones or drone brood, this should concern you as a honey bee breeder.
Happy Fathers Day!!