but, wouldn't there really be many many more than 24 possibilities, considering each worker egg has its unique combination of genes pulled from the queen at random?
but, wouldn't there really be many many more than 24 possibilities, considering each worker egg has its unique combination of genes pulled from the queen at random?
Squarepeg, you are talking about the mother that is the queen that was mated before the drone was born. I am talking about a sister. They may have been drone on the same day. Half the genes of the sister and all the genes of the brother are the same genes. not alike. they re the same identical genes. Any female that results from such a pairing woudl be 75% the genes of the original queen and 25% the genes of it's grandfather. Any male woudl be half and half.
Regardless the genetic mix of such a close relation would very likely result in an infertile egg anyway or in the case of the bee a drone layer. that is due to even more complex qualities of Chromosomes. If they get to much alike think of it like trying to put to magnets together with matching poles. they repel each other.
Not every egg the queen produces is unique. the colony consists of different genetic combinations this is true. but the number of those combinations are limited to how many drones the queen mated with. so if she only mated with 12 drones. the colony is limited to only 12 different gene combinations. Drones do not produce sperm with different sets of genes.
Bees being haploid means my second example above is correct. Haploid means there is only one set of chromosomes. in the case of a female it gets one from the female one from the male. In the case of a male it only has the one from the female. One sex gene means a male, two means a female.
It would be interesting to know the details of how the cape be is able to produce female offspring from two females only. I am very aware that many wild things can and do happen. their are species that can convert from haploid to diploid also.
Genetics are very complicated. so much so that we still don't know even nearly everything about them. Dosages effects. genes that turn on and off. The location of the chromosomes on the strand of DNA in relation to other chromosomes and much more all play a factor.
In the end you manage it all by simply observing the bees and picking the best. and that is pretty much it.
The important question. is how do you keep that trait going once you find it? Lets say you are the luck one to stumble across the 100% varroa resistant bee. How do you not loose that trait due to all these other factors that seem to want to destroy it as fast as it was found? Actually you develop traits by selection, and you want to be able to select from as wide a genetic pool as possible. but once you develop that trait you set it by inbreeding or line breeding.
A very effective method of setting a trait is rotational line breeding. This method requires that you have 4 unrelated genetic lines that have all been highly selectively bred. you can have lines that where selected for 4 separate traits. but it works better if all 4 lines where selected for the same trait. We will call these 4 lines 1,2,3 and 4
The offspring or queens from line 1 are then bread to the males of line two. the queens from line two are likewise bread to line 3 etc. ending with the queens from line 4 being bred to the males of line 1. This first generation now gives us a genetic mix of 1-2, 2-3, 3-4, 4-1. Confused yet? Don't worry you will be. Now the queens produced from the 1-2 pairings are bred to the males of line 3 resulting in a possible 1-2, 1-3 or 2-3 genetic mix. The same is true for the queens produced from the other three crosses. you now have 12 different possible genetic mixes that hopefully all still show strong varroa resistance in all 12 lines. You then again take the queens produced from these paring and mate them to drones from the next line. The pairing now become so numerous I will not try to list them all. again you mate the queens produced to the drones of the next line. You have now have 4 generations of bees that have been mated to the next unrelated line. the genetic pool has become enormous. the chosen trait has also taken a big hit. This is what you do to fix that. you now take the queens of the 5th generation and breed them back to the original males of their original line. You now just dumped half of the original genes back into the mix. you also just cut out half of the genetic mix you spent 4 generations producing. In effect you just added a fresh dose of concentrated desired trait to the entire thing. You then go through the entire rotation again. ending at the 10th generation with mating back to the original males again. at some point you will begin to see that all the bees are retaining strongly the trait for resistance.
In the case of bees, they can reproduce from generation to generation so fast that this could actually be done in a matter of months. The down side is that all queens that will be used would have to be II.
This method answers a lot of problems with selective breeding in that it does not reduce or bottle neck the genetic pool but actually dramatically increases it. It will produce traits so well set that when there is very delayed loss of those traits when you take those bees and cross them to others to add another trait to them. You can do one set of lines that is working on varroa resistance. while working on another line that is about honey production. as both lines become more and more set you then start crossing the two sets of liens with each other and you end up with 8 lines of bees that all have better varroa resistance and honey production. You separate them again and focus on just the chosen trait of each and later cross them again.
You not only do not get the loss of trait like you do with selective breeding alone. but when you stop breeding and let the bees go on their own. you do not see as fast a decline in those traits even then. Selective breeding will result in a reversal of all progress in just a few generations. rotational line breeding does not. At least that is the rule of thumb.
i only got through your first paragraph, but
>>Squarepeg, you are talking about the mother that is the queen that was mated before the drone was born. I am talking about a sister. They may have been drone on the same day. Half the genes of the sister and all the genes of the brother are the same genes. not alike. they re the same identical genes. Any female that results from such a pairing woudl be 75% the genes of the original queen and 25% the genes of it's grandfather. Any male woudl be half and half.
not so dan, they are not the same identical genes. no two eggs laid by any queen have identical genes. read up on miosis.
I called the sex genes X and Y the link below states them as just two different alleles. (Allele is another word for gene) It graphically portrays them as red and yellow. The blue signifies an unknown allele contributed by the male.
According to this source the drone can be produced by both an infertile egg containing only the set of chromosomes from the queen or from a fertile egg that receives a male allele from the drone. I have never heard it calmed that a fertile egg will produce a drone before. That is a significant omition.
According to the information in the link there are two sex allele. but a male can result if an egg is laid that only has one allele. I would have to have more information how this is possible otherwise my theory is more sound.
He is claiming that even thou there are two sex genes, a male is the result of there only being one sex gene. yet every female possesses both genes , that is why she is female.
Every female bee including the queen has both X and Y genes. Every drone will have either X or Y depending on what gene the egg had that eh queen laid without it being fertilized.
This drone now only has the one sex gene.
Now you would consider that half of every egg a queen produces will contain one of the sex genes or the other. so half of the drones she produces will be X drones. the other half will be Y drones. Any queen that a drone mates with will produce half of her eggs with the same sex gene as the drone. resulting in at least half of her fertilized eggs being drones. or eggs with the same sex genes even though there are two of them they result in a drone.
This obviously is not true. He does mention that fertilized eggs producing drones happens. but on a spotty shot gun sort of frequency. He claims 50% drone brood as extreme and a result of inbreeding. So without other information to support this. it simply is not holding it's own under closer examination.
He does mention that there are thought to be as many as 19 sex genes. and that only a match would result in a drone. This is something I would have to look not further to understanding how it applies. It would explain the dramatic reduction in exact combinations that in fact result.
Basically what he is saying is that there is not just an XY,YX XX, or YY combination that is possible. but there is a gene for eery letter of the alphabet from A to S. and that you can have any combination of those 19 genes. any combination that results in two different genes results in a female. Btu only 19 possible combinations woudl result in males.
The part I still struggle with is that a male an also result form just one allele when a queen lays an unfertilized egg. This is saying that you can genetically arrive at a male bee in two completely different ways. not impossible I suppose. but not very likely either. One male is abnormal and cannot reproduce. That is convenient since if it did it would completely dismantle the female dominance thing of the hive. actually he describes that the females of the hive actually destroy the abnormal diploid drone as it emerges.
Women take note. In order for you to achieve world dominance you cannot allow abnormal males to live. Abnormal is defined as any male with a full set of genes. And half a brain.
I do find this idea of 19 sex genes very interesting though.
I am certain that as I look further into the actual facts of be genetics it will continue to get far more complicated. Keep in mind my comments earlier where made with no looking into the actually genetics of bees. it was comments on the basics of how genetics work. I have often said. it is not that simple.
I say that to be very clear to anyone reading this. don't go off thinking that bees only have X and Y sex genes. that is not what I was saying. I was just using X and y to explain how combinations of genes then work.
If you want to go out and say anything actually happens that has any likely hood of being correct. quote the comments I put in this post. And do that with a grain of salt.
In the end genetics are complicated layered over complicated layered over complicated.
i think yes, but here's what your up against.
the honey bee genome contains around 10,000 genes.
the queen, being female like the workers, has a double set of genes, and the drones have a single set of genes.
the queen's and worker's double set comes about by the combination of an egg and a sperm.
the egg is a cell manufactured in the queen's ovary and is made with only a single set of genes. this single set of genes comes about by the splitting of the ovary cells dna into two single sets of genes. the composition of the single set of genes in the new egg cell has an almost limitedless number of possibilities, because when the dna splits, it can pull the gene from the queen's mothers side or it can pull the gene from the queen's father's side.
when an egg is fertilized, it receives the set of genes from the sperm that the sperm received when it's egg was made in the ovary.
that's 10,000 times how ever many possibilities for the genetic make up of a bee.
this is why every bee, whether queen, worker, or drone, is as much an individual genetically as you and i. our bee populations are comprised of the most genetically diverse individuals one could imagine. we have to try really hard to mess that up.
having said that, and if you subscribe to the theory that genetic diversity is good, than one would want to strive to introduce diverse genetics into their apiary, and avoid flooding with all one source.
Daniel, you have a good basic understanding of the genetics but you forgot about recombination of chromosomes when the eggs are formed, therefore variation is increased in the queens drone population as well. Square, it's not limitless, chromosomes recombine in certain regions more than others, and it depends how 'inbred' the queen is as well in terms of traits you're looking at. If she's fixed for a lot of them, variability will be small since even after recombination, alleles would be the same.
understood jr. but that's still a lot more diversity than appears to have been considered so far.
maybe only in the millions of possibilities instead of the gazillions? :)
do you think one could find two genetically identical indivuals in a colony?
and to your complete op adam,
does the bond method lead to decrease in genetic diversity?
my opinion is, probably, a little. but maybe that's not so bad, and, nature is already doing it anyway.
but, at the same time, nature is also ensuring genetic diversity.
Identical individuals in a hive, I would say it's possible depending on how many different drones the queen mated with and her genetic make up. Just depends on your definition of identical. Could have the same genetic make up, but different allele combinations on chromosomes but in the end the same alleles in total if you get my meaning. Ab aB vs AB ab.
Going on that post that mentioned Marla. I can see where she's getting at especially when you think about the mating practicies of bees. The chances of a drone being successful for any given hive is small, therefore you may lose diversity quickly.
very cool jr. i'll locate and read marla's paper, and i wish that i could hear a copy of mike bush's talk about it.
i'm just a beginner, lot's more to learn.....
thank-you for your posts. :)
unable to find a link to marla's work, does anyone have it?
this is a new site to me. looks like some good winter reading.
this one appears to touch the most on the topic of this thread.
From the source I am reading it says there are about 15,000 genes in the honey bee.
But realize that right off the bat half of those are the ones we don't want. so there are really only at most 7500 genes we want at all. but it is actually bigger than that. there are 4 genes associated with hygienic. but to have hygienic bees we can only have 1 of them so if other traits are similar the number of genes we actually even want is really more like 3750. Btu it si not true that every trait only has 4 genes associated with it. sex alone has 19. we only need two. but lets say we keep half of them just cause we are good conscience beekeepers with a healthy genetic diversity. So on and so forth.
In the end any individual queen actually only has 32 of those possible 15,000 genes. how is that for pairing it down to a bit of a bottle neck?
"Haplo-diploid systems are ideal for scaling up
from single gene effects to collective impacts
because these systems have adults that are either
haploid or diploid. Comparing across haploid
and diploid conspecifics may thus shed
light on the collective impacts of some genetic
traits. And indeed, data do suggest that males of
some eusocial hymenopterans are more susceptible
to certain pathogens, for example Varroa
mites in honey bees (94)"
(a quote from the marla spivak paper in the previous post)
when i translated that into english for myself, to me it read:
'if your queen is interbreeding with drones that are close to her genetically, studies suggest you may loose some pest/pathgogen resistance'
is that how you see it jr? specialkayme?
>>In the end any individual queen actually only has 32 of those possible 15,000 genes. how is that for pairing it down to a bit of a bottle neck?
dan, are you confusing the number of chromosomes with the number of genes?
I did find this interesting regard to bee genetics in the stuff I have been reading today.
Quote: we have 46 chromosomes, we get 23 from our mother's egg and 23 from our fathers sperm. Bees have a different number of chromosomes. Females, workers and queens have 32, 16 are contributed by the queen's eggs and 16 come from the drones sperm. Since drones hatch from unfertilized eggs, they only have the 16 chromosomes that were in the egg. Drones are haploid because they only have one set of chromosomes.
You'll notice that the egg can only carry half of the queens 32 chromosomes so she can only pass on half of her genes to her offspring. Each egg contains a unique collection of her genes, so each egg is different. Drones on the other hand only have 16 chromosomes to begin with, so each sperm must contain all the genes of the drone. This means that each sperm from a drone is exactly identical, they are clones. This is different from most other animals, where each sperm is unique, just like each egg is. End quote.
So although I did figure a clone in the mix i had it misplaced. The sperm is the clone of the drone rather than the drone being a clone of the queen. If you follow the train. the queen gives the drone his genes. the drone gives the sperm it's genes and the sperm gives it's genes to a fertile egg or female bee. My placement of the clone in the string was off by one. This is because it is the queen that has two sets of genes rather than one.
The effect is that every bee in the colony gets 100% of the genes of the drone.
A second quote from the source puts it this way.
Quote "The effect of this multiple mating is that the colony is composed of different subfamilies. Each subfamily has the same mother but different fathers. Remember that all the sperm from each drone is an identical clone. This means that the workers inherit 50% of the queens genes, but 100% of the drones genes. The workers that belong to the same subfamily are related by 75%, they are called supersisters. End Quote.
I thought the Supersister detail was interesting and was one combination I did not see.
If you are like me it takes a bit of effort to see how it works. But every bee in the hive gets 100% of the drone genes. so sister from the same drone are 50% identical or clones. In addition these sisters will have half of the queens genes that are identical. making them 75% full blood relation.
Again if you think about this it once again shows how even huge numbers of genes can get dwindled down very quickly. And that is the subject of this thread. i am just trying to show various ways in which the gene pool does get reduced. Not necessarily in actually correct ways that genes work in bees. but in accurate enough ways that gene diversity does get lost.
The overall message is it takes a lot more colonies or individual queens to actually have a big 10 or 15,000 gene pool. and even then when you look in at the individual hive that pool gets trimmed to near nothing without doing anything wrong.
I have always found that how the numbers actually work to be misleading when it comes to genetics.
realistically in order to maintain the entire 15,000 gene pool. you are probably looking at a minimum of 400 hives and probably closer to 1000. I don't think that most people when they consider genetic diversity are aware of this. They think 15,000 genes in my one hive. and that is anything but true. they even think 15,000 genes within range of my hand full of hives. and that is very likely not true.
About the only person keeping a 15,000 gene pool is mother nature.
I very well could be wrong though. I didn't read the paper, just your quote.
thanks dan. and you just pointed out a mistake i made in one of my posts above.
the drone's cells are haploid, so there is no miosis, or splitting of the dna when a sperm cell is made.
all of the sperm from a given drone would be the same genetically.
all the more reason why to have diversity, especially in the drone population.