I'm back home now, wrting on my "old faithful" computer (the new one has been giving me all sorts of "challenges" so I haven't been using it much) but I'm still suffering from the time-readjustment process, after coming home from NY. I hope my brain will be lucid enough to be able to say what I want to, clearly.
Lee, I told you "As to relatedness of drones, more on that later." The time has come.
We all know that workers and queens are "diploid" (having their chromosomes in pairs) whereas drones are haploid, (having only one member of each chromosome). While the entire set of chromosomes from the drones that mate with the queen is represented in the workers of the next generation, the queen passes on to her offspring a mixture of chromosomes, some from her mother and some from her father. That means that we can have a greater control over the genetics of our bees through selecting males than we can by selecting females. Said differently, drone selection (from hives with the traits we want) can be more effective than queen selection. However, in IIQ (Instrumental Insemination of Queens) we usually use semen collected from about 10 drones, and obviously, their chromosomes (and DNA) won't be identical.
In many genetic projects, scientists improve the traits we want to get by controlled mating of selected males with selected females. These are often siblings with each other and even parent with child. This, for example, is done with cattle, chickens, and vegetables to quickly isolate and improve on selected traits.
However, with bees, we have a different problem. Robert Page Jr. and Harry Laidlaw Jr., in their article "Closed Population Honeybee Breeding" report on sex determination in honeybees. While one gene (composed of two alleles) determines sex, if both alleles are identical, it leads to a non-viable egg. This will show up in the pattern of larvae that develop from the brood of a queen. If her eggs have two differeent alleles for the sex gene, the pattern of developing brood will be solid. On the other hand, if she has sperm from drones with the same sex allele as she has, her brood pattern will be spotted. The eggs that didn't develop will be cleared away by the worker bees, leaving empty cells mixed in among the developing brood. There are some six to nine different sex alleles for honeybees and if we select our drones for IIQ from a closed population of bees (drones and queens closely related) we increasse the likelihood of getting these non-viable eggs.
Two considerations of this complicating factor are:
1. While we would like to improve our stock by choosing from related queens and drones, we must always realize that we should look for the desired traits in isolated (distantly located) populations, hoping that, while the alleles for the desired traits will be in both populations, the sex alleles will be different.
2. Before an IIQ is sold, it MUST be checked for its brood pattern, making ourselves as certain as possible that the mating has not lead to a queen that will lay unacceptable numbers of non-viable eggs.
Thus, a major consideration for IIQ is selecting the sperm donors from a desirable hive that is "distant" from the queen's hive,
Until now, I had always thought that a spotted pattern of brood was because the queen was a "sloppy" layer, It turns out that she may have laid a solid pattern of eggs, but, because of the incompatibility of the sex alleles, eggs she laid simply didn't develop. The upshot of this is to think seriously about replacing such a queen sooner, rather than later (assuming that she has been laying for a while), not just starting,and still produces spotted patterns.
