I've posted a few times in here about how I believe (based on information presented by other breeders -- unfortunately, I'm not in a position to have my own peafowl and conduct my own experiment) that Peach is really the result of combining Purple and Cameo. According to the history of the Peach information on the Legg's Peafowl Farm website, Clifton Nicholson crossed a Cameo male to a Purple female, producing two male offspring who were regular IB in phenotype, but were split to Purple and Cameo. When these males were bred back to their Purple mother, they produced eleven chicks -- 2 male and 1 female IB, 3 female Cameos, 2 male and 2 female Purples, and 1 female Peach (the first). I will now explain what I think happened. First, a little genetics lesson.
Genes are found on chromosomes, of which all but the sex chromosomes come in matched pairs. The sex chromosomes are so-called because in one sex, there is one configuration, while in the opposite sex, there is another.
Birds differ from mammals with regards to sex chromosomes. In mammals, males are XY and females are XX. In birds, males are ZZ and females are ZW. This means that with regard to sex-linked mutations (i.e., those carried on the sex chromosomes), female mammals and male birds can be heterozygous, or carriers -- they have one copy of the mutated gene and one copy of the normal gene. Male mammals and female birds, because they have only one X or Z (respectively), cannot be heterozygous -- if they have the mutated gene, they have only one copy, and they show the trait. For the rest of this post, I will be talking about birds (male ZZ, female ZW).
When birds make a sperm or egg cell, there is a process called meiosis which takes place. Basically, a body cell has to get from pairs of each chromosome down to just one of each chromosome, so that when it combines with a cell from its mate, the resulting cell will have chromosomes in pairs again. Within this process, things often get shuffled around, which increases genetic diversity. Offspring receive half their chromosomes from one parent and the other half from the other parent. But when that offspring produces its own eggs or sperm, it's pretty random which way the chromosomes get split up -- it is rare that a sperm has all the chromosomes from the male's father (or mother).
Another process usually takes place which also increases genetic diversity. This is called crossover. Basically, the chromosomes line up into matched pairs, and some of them "cross over" each other (like when you cross your fingers). When this happens, there is a break at the cross point, and the chromosomes switch parts. Imagine when you cross your fingers that the top of your pointer and the top of your middle finger break off, and reattach onto the opposite finger. Now you have a new mix of information -- pointer base with middle finger tip, and middle finger base with pointer tip. This is the same basic thing that happens with the chromosomes -- instead of a whole chromosome from Dad, now it has a piece switched with the chromosome from Mom, and vice versa.
OK, now back to the parents of that first Peach hen. Dad (let's call him Pete) has two Z chromosomes. One Pete got from HIS dad (let's call him Dave), and that had the Cameo mutation on it. The other Z chromosome came from his mom (let's call her Doris), and that had the Purple mutation on it. Cameo Dave had two copies of Cameo, because he had two Z chromosomes. Purple Doris needed only one copy of Purple, because she had only one Z chromosome. Pete looks like a regular India Blue, because to look Cameo he'd need two copies, and to look Purple he'd need two copies. Instead, he has one of each, so we say Pete is IB split to Purple and Cameo.
Pete gets mated to Doris. Pete can give one Z chromosome, which will be either the one with Purple on it, or the one with Cameo on it. Doris has only one Z chromosome to give, so it's either that (with Purple, and will make the chick a boy), or the W (which has neither mutation, and will make the chick a girl).
If you make a Punnet Square for this breeding, you'll find that you can get:
Purple boys (Purple Z from Pete, Purple Z from Doris)
IB boys split to Purple and Cameo (Cameo Z from Pete, Purple Z from Doris)
Purple girls (Purple Z from Pete, W from Doris)
Cameo girls (Cameo Z from Pete, W from Doris)
These are the only possibilities according to a Punnet Square. But these aren't the only possibilities we found. There are two more.
IB girl
Peach girl
First, let's look at the IB girl.....
Wait, that doesn't make sense, right? How could you get an IB girl? The girls get their Z from Pete, and Pete doesn't have a Z without a mutation on it. One of Pete's Z's has Cameo, and the other has Purple. So all his daughters would HAVE to be Cameo or Purple, right?
According to a Punnet Square, yes. But a Punnet Square has a shortcoming -- it doesn't account for crossover, and only by crossover could Pete have an IB daughter. Crossover at a specific location is rare, but it does happen every so often. I'll explain.
Remember the analogy of crossing your fingers, and breaking off and switching fingertips? OK, let's say that you put a P on your pointer fingertip, and a C on the base of your middle finger. This represents the mutations for Purple and Cameo on the Z chromosomes -- they are in different locations within the chromosome (I don't know where exactly, only that they're not in the same spot). To start, you have one finger that's Purple and one that's Cameo. If you cross your fingers, break the tips, and reattach onto the opposite finger, now you have a new setup. Your first finger will not have any letters on it (let's call it "normal IB" because there are no mutations on it), and your second finger will have a P on the tip and a C on the base.
This is like what happened to Pete. His Z chromosomes crossed over during sperm formation, and instead of having one Z with Purple or one Z with Cameo, some sperm were formed with one Z with NEITHER and one Z with BOTH. One of those Z's with NEITHER fertilized the egg that became the IB girl, and one of the Z's with BOTH fertilized the egg that became the Peach girl. Crossover is the likely explanation for those two additional female offspring who didn't appear in the possibilities according to a Punnett square. Another possible explanation is that a random mutation happened in the IB girl (or the sperm that fertilized the egg from which she developed), which "fixed" the Purple or Cameo gene back to normal IB, and the identical mutation happened in the Peach girl, as well as another, independent, random mutation happened IN THE SAME SPERM that caused it to become a brand new mutation, which we call Peach. So if Peach is NOT a combination of Purple and Cameo, then one random mutation that "fixed" the Cameo or Purple mutation must have happened twice in the same clutch, and then another random and independent mutation happened which caused Peach. Or....the simpler and more likely-to-happen explanation -- crossover, and Peach is really Purple Cameo.
There are ways of test-breeding to confirm or deny either hypothesis without having to sequence the genes on the peafowl's Z chromosome. One way is through a trio that Clifton Nicholson set up, and described to me recently in email correspondence. He used a Peach male with a Purple female and a Cameo female. His first three chicks were two Peach and one that is either Purple or Cameo (he couldn't tell at the time he wrote me last, but it wasn't IB). So let's see which model of Peach works with this outcome.
If Peach is Purple Cameo, then the male has 2 Z's, each with Purple Cameo. The Female (let's say it was the Purple female, and the offspring is Purple) has only 1 Z with Purple on it. We would get:
Purple boys (Purple Cameo Z from Dad, Purple Z from mom)
Purple boys (Purple Cameo Z from Dad, Purple Z from mom)
Purple Cameo girls (Purple Cameo Z from Dad, W from mom)
Purple Cameo girls (Purple Cameo Z from Dad, W from mom)
If Peach is a unique mutation, then the male has 2 Z's, each with one mutation (Peach). The Purple female is the same.
IB boys (Peach Z from Dad, Purple Z from mom)
IB boys (Peach Z from Dad, Purple Z from mom)
Peach girls (Peach Z from Dad, W from mom)
Peach girls (Peach Z from Dad, W from mom)
Thus to give evidence that Peach is really Purple Cameo, I can invoke the results of of a test-breeding which match the results of one model of inheritance over the other. If you breed a Peach male to a Cameo or Purple female, you will get either Peach females or males colored like their mother. If Peach were a separate mutation, the males would be IB.
OK, so what does this mean for people out there? If you want to try your hands at making your own Peach, you can breed a Purple to a Cameo (the gender of either doesn't matter). The female chicks will be colored like the father, while the male chicks will be IB and split to Purple and Cameo (just like the father of the first Peach peahen bred by Clifton). If you use that male enough, you'll likely get (eventually) a female Peach. This fits my model, and if you try it and it works, confirms my model. And...it means you can make your own Peach.
NOW...fun part...All this is hard to get because it relies on crossover. Purple and Cameo are mutations on the same chromosome, so you have to wait for the random event to occur. But if you breed a sex-linked mutation with any of the ones that AREN'T sex-linked, it's just a matter of crossing the F1's to get visual birds in the F2 generation. For example, if you wanted to see what happens when combining the gene for Purple with the gene for Midnight, you can go about it this way: Purple male X Midnight female = Purple females split to Midnight, and IB males split to Purple and Midnight. If you breed one of the F1 males split to Purple and Midnight back to a Midnight, then 1/2 of the female chicks will be Purple Midnight (the other 1/2 of the female chicks will be Purple split to Midnight...and you won't get visual males until the F3 generation this way). Or, if you bred the F1's among themselves, you'll get some Purple Midnight males and females in the F2 generation.
Combining mutations is common in other bird species. I remember reading that the Salmon Golden Pheasant is the result of combining Dark Throated with Cinnamon (Or was it another color? I might be wrong on Cinnamon, but I know that "Salmon" is a combination.). It's easier when the mutations are on different chromosomes. But even when they're on the same chromosome, it's possible to recombine traits
An example in chickens is the "blue egg gene" and the "pea comb" lying close together on the same chromosome. Generally, what I've learned through the Olive Egger thread is that to follow the dominant "blue egg gene" in cockerels, one can follow the "pea comb" since they usually travel together. But sometimes they do separate as a result of genetic crossover. Proof of this is in the breed called the Cream Legbar, which has a single comb but lays blue eggs.
Through this post, I've hoped to convince you that it is possible for Peach to be Purple-Cameo. Further test-breedings will confirm or deny my hypothesis. If it is confirmed, then I hope that it will open the door to future experimental crosses. Perhaps Bronze-Midnight would give a shiny black peafowl. I already have seen Clifton Nicholson's "Indigo" peafowl pics (which he made by combining colors), and hope he will submit an article about them soon, so everyone can see them. And then, in a few years when I'm finally done with school, I can settle down and buy some property, and seek out all you adventuresome breeders who have put together something beautiful that doesn't even exist yet -- but might come about as a result of this post.
Genes are found on chromosomes, of which all but the sex chromosomes come in matched pairs. The sex chromosomes are so-called because in one sex, there is one configuration, while in the opposite sex, there is another.
Birds differ from mammals with regards to sex chromosomes. In mammals, males are XY and females are XX. In birds, males are ZZ and females are ZW. This means that with regard to sex-linked mutations (i.e., those carried on the sex chromosomes), female mammals and male birds can be heterozygous, or carriers -- they have one copy of the mutated gene and one copy of the normal gene. Male mammals and female birds, because they have only one X or Z (respectively), cannot be heterozygous -- if they have the mutated gene, they have only one copy, and they show the trait. For the rest of this post, I will be talking about birds (male ZZ, female ZW).
When birds make a sperm or egg cell, there is a process called meiosis which takes place. Basically, a body cell has to get from pairs of each chromosome down to just one of each chromosome, so that when it combines with a cell from its mate, the resulting cell will have chromosomes in pairs again. Within this process, things often get shuffled around, which increases genetic diversity. Offspring receive half their chromosomes from one parent and the other half from the other parent. But when that offspring produces its own eggs or sperm, it's pretty random which way the chromosomes get split up -- it is rare that a sperm has all the chromosomes from the male's father (or mother).
Another process usually takes place which also increases genetic diversity. This is called crossover. Basically, the chromosomes line up into matched pairs, and some of them "cross over" each other (like when you cross your fingers). When this happens, there is a break at the cross point, and the chromosomes switch parts. Imagine when you cross your fingers that the top of your pointer and the top of your middle finger break off, and reattach onto the opposite finger. Now you have a new mix of information -- pointer base with middle finger tip, and middle finger base with pointer tip. This is the same basic thing that happens with the chromosomes -- instead of a whole chromosome from Dad, now it has a piece switched with the chromosome from Mom, and vice versa.
OK, now back to the parents of that first Peach hen. Dad (let's call him Pete) has two Z chromosomes. One Pete got from HIS dad (let's call him Dave), and that had the Cameo mutation on it. The other Z chromosome came from his mom (let's call her Doris), and that had the Purple mutation on it. Cameo Dave had two copies of Cameo, because he had two Z chromosomes. Purple Doris needed only one copy of Purple, because she had only one Z chromosome. Pete looks like a regular India Blue, because to look Cameo he'd need two copies, and to look Purple he'd need two copies. Instead, he has one of each, so we say Pete is IB split to Purple and Cameo.
Pete gets mated to Doris. Pete can give one Z chromosome, which will be either the one with Purple on it, or the one with Cameo on it. Doris has only one Z chromosome to give, so it's either that (with Purple, and will make the chick a boy), or the W (which has neither mutation, and will make the chick a girl).
If you make a Punnet Square for this breeding, you'll find that you can get:
Purple boys (Purple Z from Pete, Purple Z from Doris)
IB boys split to Purple and Cameo (Cameo Z from Pete, Purple Z from Doris)
Purple girls (Purple Z from Pete, W from Doris)
Cameo girls (Cameo Z from Pete, W from Doris)
These are the only possibilities according to a Punnet Square. But these aren't the only possibilities we found. There are two more.
IB girl
Peach girl
First, let's look at the IB girl.....
Wait, that doesn't make sense, right? How could you get an IB girl? The girls get their Z from Pete, and Pete doesn't have a Z without a mutation on it. One of Pete's Z's has Cameo, and the other has Purple. So all his daughters would HAVE to be Cameo or Purple, right?
According to a Punnet Square, yes. But a Punnet Square has a shortcoming -- it doesn't account for crossover, and only by crossover could Pete have an IB daughter. Crossover at a specific location is rare, but it does happen every so often. I'll explain.
Remember the analogy of crossing your fingers, and breaking off and switching fingertips? OK, let's say that you put a P on your pointer fingertip, and a C on the base of your middle finger. This represents the mutations for Purple and Cameo on the Z chromosomes -- they are in different locations within the chromosome (I don't know where exactly, only that they're not in the same spot). To start, you have one finger that's Purple and one that's Cameo. If you cross your fingers, break the tips, and reattach onto the opposite finger, now you have a new setup. Your first finger will not have any letters on it (let's call it "normal IB" because there are no mutations on it), and your second finger will have a P on the tip and a C on the base.
This is like what happened to Pete. His Z chromosomes crossed over during sperm formation, and instead of having one Z with Purple or one Z with Cameo, some sperm were formed with one Z with NEITHER and one Z with BOTH. One of those Z's with NEITHER fertilized the egg that became the IB girl, and one of the Z's with BOTH fertilized the egg that became the Peach girl. Crossover is the likely explanation for those two additional female offspring who didn't appear in the possibilities according to a Punnett square. Another possible explanation is that a random mutation happened in the IB girl (or the sperm that fertilized the egg from which she developed), which "fixed" the Purple or Cameo gene back to normal IB, and the identical mutation happened in the Peach girl, as well as another, independent, random mutation happened IN THE SAME SPERM that caused it to become a brand new mutation, which we call Peach. So if Peach is NOT a combination of Purple and Cameo, then one random mutation that "fixed" the Cameo or Purple mutation must have happened twice in the same clutch, and then another random and independent mutation happened which caused Peach. Or....the simpler and more likely-to-happen explanation -- crossover, and Peach is really Purple Cameo.
There are ways of test-breeding to confirm or deny either hypothesis without having to sequence the genes on the peafowl's Z chromosome. One way is through a trio that Clifton Nicholson set up, and described to me recently in email correspondence. He used a Peach male with a Purple female and a Cameo female. His first three chicks were two Peach and one that is either Purple or Cameo (he couldn't tell at the time he wrote me last, but it wasn't IB). So let's see which model of Peach works with this outcome.
If Peach is Purple Cameo, then the male has 2 Z's, each with Purple Cameo. The Female (let's say it was the Purple female, and the offspring is Purple) has only 1 Z with Purple on it. We would get:
Purple boys (Purple Cameo Z from Dad, Purple Z from mom)
Purple boys (Purple Cameo Z from Dad, Purple Z from mom)
Purple Cameo girls (Purple Cameo Z from Dad, W from mom)
Purple Cameo girls (Purple Cameo Z from Dad, W from mom)
If Peach is a unique mutation, then the male has 2 Z's, each with one mutation (Peach). The Purple female is the same.
IB boys (Peach Z from Dad, Purple Z from mom)
IB boys (Peach Z from Dad, Purple Z from mom)
Peach girls (Peach Z from Dad, W from mom)
Peach girls (Peach Z from Dad, W from mom)
Thus to give evidence that Peach is really Purple Cameo, I can invoke the results of of a test-breeding which match the results of one model of inheritance over the other. If you breed a Peach male to a Cameo or Purple female, you will get either Peach females or males colored like their mother. If Peach were a separate mutation, the males would be IB.
OK, so what does this mean for people out there? If you want to try your hands at making your own Peach, you can breed a Purple to a Cameo (the gender of either doesn't matter). The female chicks will be colored like the father, while the male chicks will be IB and split to Purple and Cameo (just like the father of the first Peach peahen bred by Clifton). If you use that male enough, you'll likely get (eventually) a female Peach. This fits my model, and if you try it and it works, confirms my model. And...it means you can make your own Peach.
NOW...fun part...All this is hard to get because it relies on crossover. Purple and Cameo are mutations on the same chromosome, so you have to wait for the random event to occur. But if you breed a sex-linked mutation with any of the ones that AREN'T sex-linked, it's just a matter of crossing the F1's to get visual birds in the F2 generation. For example, if you wanted to see what happens when combining the gene for Purple with the gene for Midnight, you can go about it this way: Purple male X Midnight female = Purple females split to Midnight, and IB males split to Purple and Midnight. If you breed one of the F1 males split to Purple and Midnight back to a Midnight, then 1/2 of the female chicks will be Purple Midnight (the other 1/2 of the female chicks will be Purple split to Midnight...and you won't get visual males until the F3 generation this way). Or, if you bred the F1's among themselves, you'll get some Purple Midnight males and females in the F2 generation.
Combining mutations is common in other bird species. I remember reading that the Salmon Golden Pheasant is the result of combining Dark Throated with Cinnamon (Or was it another color? I might be wrong on Cinnamon, but I know that "Salmon" is a combination.). It's easier when the mutations are on different chromosomes. But even when they're on the same chromosome, it's possible to recombine traits
An example in chickens is the "blue egg gene" and the "pea comb" lying close together on the same chromosome. Generally, what I've learned through the Olive Egger thread is that to follow the dominant "blue egg gene" in cockerels, one can follow the "pea comb" since they usually travel together. But sometimes they do separate as a result of genetic crossover. Proof of this is in the breed called the Cream Legbar, which has a single comb but lays blue eggs.
Through this post, I've hoped to convince you that it is possible for Peach to be Purple-Cameo. Further test-breedings will confirm or deny my hypothesis. If it is confirmed, then I hope that it will open the door to future experimental crosses. Perhaps Bronze-Midnight would give a shiny black peafowl. I already have seen Clifton Nicholson's "Indigo" peafowl pics (which he made by combining colors), and hope he will submit an article about them soon, so everyone can see them. And then, in a few years when I'm finally done with school, I can settle down and buy some property, and seek out all you adventuresome breeders who have put together something beautiful that doesn't even exist yet -- but might come about as a result of this post.
