Beemaster's International Beekeeping Forum

BEEKEEPING LEARNING CENTER => GENERAL BEEKEEPING - MAIN POSTING FORUM. => Topic started by: Seabee8 on July 27, 2015, 10:17:29 AM

Title: Drones & unfertilization
Post by: Seabee8 on July 27, 2015, 10:17:29 AM
I have not been able to find an explanation as to why an unfertilized egg becomes a drone. How can a non fertilized egg grow into a live creature?
Title: Re: Drones & unfertilization
Post by: Hops Brewster on July 27, 2015, 10:53:16 AM
Drones carry only one set of chromosomes from the mother.  This is 'haploid'.  When the egg develops inside the queen, diploid cells with 32 chromosomes divide into haploid cells with 16 chromosomes, which is a haploid egg.  Look up 'haplodiploid sex determintation'.
Title: Re: Drones & unfertilization
Post by: Colobee on July 27, 2015, 11:55:56 AM
Along that line of questioning, are drones from a laying worker still fertile?
Title: Re: Drones & unfertilization
Post by: Michael Bush on July 27, 2015, 02:27:49 PM
>I have not been able to find an explanation as to why an unfertilized egg becomes a drone. How can a non fertilized egg grow into a live creature?

Haploid males and diploid females are not unique to honey bees.
https://en.wikipedia.org/wiki/Haplodiploidy

But if you need a clearer idea of how that works, in a dipoid organism there are two chromosomes for each spot on the chain.  So, for instance, you have a blue eye and a brown eye gene.  One is dominant and you end up with brown eyes.  But you carry the other gene and you have the potential to pass it on.  But only one was used.  In a haploid organism there is only one gene, let's say it's brown eye.  They can only have the color eyes that this gene says as there is no other gene to override it.  But there is a gene to define it.  Just one instead of two with only one being used.  And they can only pass on a set of genes identical to themselves as there are no pairs to choose from randomly.  So a given drone's sperm are all identical.
Title: Re: Drones & unfertilization
Post by: Seabee8 on July 28, 2015, 09:17:39 AM
Thanks for the info and the link to Haploid. Am I correct in assuming that not all of the queens eggs get fertilized?
Title: Re: Drones & unfertilization
Post by: Michael Bush on July 28, 2015, 10:13:21 AM
> Am I correct in assuming that not all of the queens eggs get fertilized?

The eggs are selectively fertilized.  The prevailing theory is that the queen measures the cell with her front legs and that "throws the switch" that causes her to either fertilize or not based on the cell size.  The ones in the worker cells are fertilized and the ones in the drone cells are not.  So you are correct that not all of them are fertilized.  That is by design and not random chance.