GREENCHEEKED MUTATIONS IN DEPTH

There is so much interest into the breeding of GreenCheeked mutations and I have found there is not much information available in a single place for use or reference. Since GreenCheeked mutations are primarily what I breed, I took the time to write an article that explains the very basics of each of the three most common mutations in the UK today. I explain how the trait effects the colour of the bird and how it is inherited. In addition I explain then how to combine the two most common which are Yellow-Sided and Cinnamon to produce what is commonly referred to as Pineapple. Hopefully this will help explain the basics a little better. I will continue to update this document and add new ones in the very near future and will also include articles on additional GreenCheeked Mutations like Blue Pineapple, Olive (Misty) GreenCheeked,Blue YellowSided, Blue Cinnamon & Pied GreenCheeked.

We are going to go over some basics of genetics and sex linked mutations. I want to just start to scratch the surface of Pyrrhura Mutations and hopefully explain and help someone understand three of the most common mutations. The three mutations that will be discussed are YellowSided, Cinnamon and Pineapple. I want to start with some definitions to verify that a basic understand is established on which the mutations can be discussed. In some ways this may seem elementary but I feel it is necessary to make sure that terms I use later on are fully understood.

CHROMOSOME COMPOSITION

In the pcittacine world the hen actually determines the sex of the off spring. The hen’s DNA genes are made up of an X chromosome and a Y chromosome. This is how the sex of the off spring is determined, by which chromosome string the hen throws during the forming of the egg.

The cock’s DNA genes are made up of two separate X chromosomes. Since they are both X chromosomes the cock has no influence on the sex of the off spring.

SEX LINKED MUTATIONS

Sex linked mutations are attached to the X chromosome since it is the only chromosome large enough to carry the gene. The Y chromosome is to small to carry any of the wild-type genes that oppose mutations carried on the X chromosome. What this means is a hen only needs one gene for a sex-linked mutation to be visual were, as a male needs two. What that means is a hen must show her “colour We are going to go over some basics of genetics and sex linked mutations. I want to just start to scratch the surface of Pyrrhura Mutations and hopefully explain and help someone understand three of the most common mutations. The three mutations that will be discussed are Yellow-Sided, Cinnamon and Pineapple. I want to start with some definitions to verify that a basic understand is established on which the mutations can be discussed. In some ways this may seem elementary but I feel it is necessary to make sure that terms I use later on are fully understood.

CHROMOSOME COMPOSITION

In the pcittacine world the hen actually determines the sex of the off spring. The hen’s DNA genes are made up of an X chromosome and a Y chromosome. This is how the sex of the off spring is determined, by which chromosome string the hen throws during the forming of the egg.

The cock’s DNA genes are made up of two separate X chromosomes. Since they are both X chromosomes the cock has no influence on the sex of the off spring.

SEX LINKED MUTATIONS

Sex linked mutations are attached to the X chromosome since it is the only chromosome large enough to carry the gene. The Y chromosome is to small to carry any of the wild-type genes that oppose mutations carried on the X chromosome. What this means is a hen only needs one gene for a sex-linked mutation to be visual were, as a male needs two. What that means is a hen must show her “colour” and can never be split to a sex linked mutation were as a cock does not have to show his “colour” and can be split.

CINNAMON MUTATION

The Cinnamon mutation is sex-linked and is well established in the UK. The basic mutation definition is that it must be sex-linked and prevents the conversion of brown feather pigment into black. Therefore, a Cinnamon bird cannot produce black or grey in any colour shade, yet there is no reduction in the amount of pigment found in the feathers. Cinnamon GreenCheeked also have plum coloured eyes that darken, as they get older. As new hatchlings they are easily recognized by this eye coloration.

 

 

YELLOW-SIDED MUTATION

The YellowSided mutation is not fully understood but is thought to actually be the Opaline Mutation. To date this mutation has exhibited all the signs to meet the criteria of the Opaline mutation. First, the Opaline mutation is sex-linked in inheritance. Second, it must alter pigment distribution but not actually create any new pigments that the species does not already have. Thirdly the underside wing strip becomes visible from the top of the wing. Even though YellowSided Black Cap Conures and YellowSided GreenCheeked Conures don’t have this feature it is still believed that they are part of this mutation. Finally, in species with grey down pigment, this is lost and the down becomes white. However the yellow pigment is not lost from the down. With these identifying features the Opaline gene reduces the spread of the grey family pigments in the bird while enhancing the spread of the yellow family pigments. The modified yellow family pigments such as red, orange or pink are emphasized in species where they already naturally occur. There is no alteration to structural colour production just an enhancement. This enhancement explains why the yellows, reds and pink have become so vibrant on YellowSided Conures. That also explains why there is such a variation in the colouring of YellowSided Conures.

Now that we have covered some of the basics lets start to get into the genetics part of this. I will use a chromosome pairing chart to show the outcome of each pairing. Since both the Cinnamon Mutation and Yellow-sided mutation are sex-linked I will show examples of either but not always both. If you remember from our discussions above a female has an X and a Y chromosome. Therefore a hen will be shown as YX. The male has two X chromosomes and will be shown as XX. Also remember that the X chromosome is the only gene large enough to carry the sex-linked mutation. So what we will do for these examples is show the mutation in superscript on the X chromosome, for example: YXcin would be a Cinnamon female. Let try one more, XcinXcin any idea? That is a full visual Cinnamon male. Keep in mind two very important rule here for sex-linked mutations. First, the female must show here mutation colour meaning if she is a Cinnamon she has to show the Cinnamon mutation. Second, the male is the only one that can be split to a sex-linked mutation. This also means he does not have to visually show the mutation. We will cover this in more detail so if it does not make total sense it will later. With that said let jump right into it.

CHROMOSOME CHARTS

To begin with lets take a look at a none mutation chromosome matching chart for a pair of ‘Normal’ GreenCheeked Conures. What this chart shows us is in this pairing theoretically you will get 50% male babies and 50% female babies. That is the crazy part about this genetic pairing stuff, it is all theoretical. Statically the numbers will work out for lets say a 1000 babies from this pair, but we all know we will never get that many. So the numbers may seem a little skewed for you because you may actually got 40% males and 60% females where as I might get just the opposite of 60% males and 40% females. It is just like flipping a silver dollar. How many times will it be heads? How many times tails?

	Y	X
X	YX	XX
X	YX	XX

Table 1In the example shown in table 1 I indicated the off spring as to their sex by colour. Remember that XX are males, those are indicated by the blue highlight and the YX are the female offspring. The hens are highlighted in pink. I think that gives us a good starting point to begin talking about the sex-linked mutations.

A similar chart would work just fine for either visual Cinnamon or visual Yellow-sided GreenCheeked Conures. Here are two more examples just to demonstrate what I mean. Keep in mind that only the X chromosome carries the mutation and for the bird to be visual all the X chromosomes must have the mutation attached to it.

	Y	Xcin			Y Xys
Xcin YXcin	XcinXcin		Xys YXys XysXys
Xcin YXcin	XcinXcin		Xys YXys XysXys

Table 2 Table 3

Table 2 and table 3 are basically the same. The off spring is split 50% male and 50% females and they are all visual babies. Since both parents are of the same mutation the babies are visual just like the parents. Table 2 shows the results of pair of Cinnamon GreenCheeked and table 3 shows the same results but with both parents being Yellow-sided GreenCheeked.

SPLITS

In sex-linked mutations only the males can be split to the mutation. Remember that it takes both X chromosomes to be carrying the mutation for the bird to be visual. If only one of the X chromosomes has the mutation that is what is called a split. That is what is referred to as “he is split to YellowSided” or “he is split to Cinnamon”. Since the mutation is only on one X chromosome the male bird will look Normal, meaning showing no or very minimal visual indications that the mutation is present. Here are some charts to help explain how splits are breed and some of the problems with breeding them. I will only use YellowSided in these examples but Cinnamon is exactly the same. On the charts just substitute the Cinnamon mutation in place of the YellowSided mutation.

	Y X			Y Xys
Xys YXys XXys		X YX XXys
Xys YXys XXys		X YX XXys

Table 4 Table 5

In table 4 we paired a visual male YellowSided with a Normal hen. What the results are, is that all the female offspring are visual YellowSided, but all the male offspring only have one X chromosome that is carrying the mutation. They are then split Yellow-sided. In table 5 for comparison we just reversed which parent was visual. Now the hen is the visual Yellow-sided and the cock is the Normal GreenCheeked. The offspring are quit different. What you see is that all the hen babies are Normal but the males are all still split to Yellow-sided. In both of these example the result are predictable and there are no unknowns. Let’s take two other examples and see what the results are.

	Y X			Y Xys
X YX XX		X YX XXys
Xys YXys XXys		Xys YXys XysXys

Table 6 Table 7In table 6 we have paired a split to Yellow-sided male with a Normal hen. The resulting offspring have now become a problem. The hens are ok. As you can see, you get 25% Normal hens and 25% Yellow-sided hens. The males are where the problems are. You get the same split that you had with the hens, meaning you will get 25% Normal males and 25% split to Yellow-sided males. That is were the problem resides. Remembering that splits look the same as Normal’s you will not be able to tell the difference between the split to Yellow-sided babies and the Normal babies. The only way to possible tell is to wait for them to mature and pair them up and see what type of babies you got. That would tell you if they were the Normals or the splits.

In table 7 we used the same male but paired him with a visual Yellow-sided hen. The results are a little different and as you can tell we don’t have the same problem that we had with the pairing discussed in table 6. The offspring from this pairing are, 25% Normal hens, 25% Yellow-sided hens, 25% Yellow-sided cocks, and 25% split to Yellow-sided cocks. The major difference between table 6 and table 7 results are the fact that the male babies can be differentiated.

DOUBLE SPLITS

Since we know have a good understanding of how splits are made and some of the issues with them let talk about the next type of splits. Since each X chromosome can carry a mutation it is possible for a male bird to be split to more than one mutation. Traditionally the term “Double Split” has meant that the male bird is split to both Cinnamon and to Yellow-sided. Later on we will see that a male can actually be “Double Split” or even “Triple Split” and not always too just these two basic mutations. But for this discussion we will only talk about the male being split to Cinnamon and to Yellow-sided. Let’s look at some charts to see how this is possible.

	Y Xcin			Y Xys
Xys YXys XcinXys		Xcin YXcin XcinXys
Xys YXys XcinXys		Xcin YXcin XcinXys

Table 8 Table 9Tables 8 and 9 are basically the same. They show both ways to make a Double Split Male. As you remember only the X chromosome can carry the mutation and since the male babies receive one X chromosome from each parent. All you do is pair a Cinnamon and a Yellow-side together. Does not matter which is the male and which is the female. That only matters when your counting on what mutation the female babies will be. As you can see in table 8, we paired a male Yellow-side with a Cinnamon hen. All the males are Double splits since they received one X chromosome from each parent and each one is carrying a mutation. As far as all the hen babies they will be all visual Yellow-sides. That is because they received their colour mutation from their father who was a Yellow-side. Now compare those results to table 9. In this table we paired a male Cinnamon with a female Yellow-side. Once again, all the males are Double Splits. But unlike table 8, all the females here are visual Cinnamon’s. So depending on if you need Cinnamon hens or Yellow-sided hens is really the only factor in deciding on how you pair up these mutations for breeding of Double Split males.Figure 8 is an example of a pairing for breeding for Double Split males. The Yellow-side on the left is the male and the Cinnamon on the right is the hen. The offspring from this pair is just like in table 8.

One thing to keep in mind when you are breeding or buying Double Split males is that they look just like a Normal GreenCheeked. They have no visual signs of either mutation. This can be an issue in your nursery as well as from a less than honest breeder if you are in the market to purchase one.

PINEAPPLE MUTATION

We are now up the one of the most desired mutations, the Pineapple. How do you breed for these beautiful birds? Well we have covered all the information needed, let’s just put the pieces together. The mutation known in the USA as a Pineapple is really the combination of two mutations together onto a single X chromosome. It is the combination of both the YellowSided and Cinnamon mutations together. That is why for so long no visual male Pineapples were available. How do you get both mutations onto a single X chromosome? That is were the Double Split male comes into the picture. In the breeding with a Double Split male to a Yellow-side or Cinnamon hen a curious thing happens every once in a while. It is called a ‘Crossover’. That is were the mutation from one X chromosome ‘Crosses Over’ and joins the other X chromosome and both mutations are combined and given to a single offspring. Since only the males can do this, the babies are only hens and that is why, we for so long have only had female Pineapples. Since the female only has one X chromosome to give to the offspring, she cannot offer any such effect like a ‘Crossover’. Therefore it really does not matter what mutation the female is in your pairings to breed for Pineapples. It really depends more on what type of visual babies you want just like in the previous discussion about Double Splits. Keep one thing in mind, just as there is a possibility for the ‘Crossover’ to happen there is a remote possibility for the male to pass on no mutation. This is a possibility but is not very probable. As in most everything, there is always a chance, but the odds are quit small. Let look at some charts to see if we can understand how this works.

	Y	Xcin			Y	Xys
Xcin	YXcin	XcinXcin		Xcin	YXcin	XcinXys
Xys	YXys	XcinXys		Xys	YXys	XysXys
Crossover	YXys-cin	XcinXys-cin		Crossover	YXys-cin	XysXys-cin
No Mutation	YX	XXcin		No Mutation	YX	XXys

Table 10 Table 11

	Y X
Xcin	YXcin XXcin
Xys	YXys XXys
Crossover	YXys-cin XXys-cin
No Mutation	YX XX

Table 12In table 10 we put a Double Split male with a Cinnamon hen, here are the results. About half of the female babies will be visual Cinnamon hens and most of the remaining hens will be visual Yellow-sided hens. Somewhere at about 10% of the time, the Crossover will happen and you will get a Pineapple hen baby. Now lets look at the males. Again about half of the males will be visual Cinnamon males while the remaining majority will be Double Split males. There will be a small number of them that will actually be Visual Cinnamon’s but will also be split to Pineapple. They will look a little different from a normal Cinnamon and I have known them to be referred to as Limes among other names. But they are actually a visual Cinnamon split to Pineapple because as you can see in table 10 there was to Crossover and he is carrying both mutations on a single X chromosome. As stated earlier there is a rare possibility that needs to be mentioned. It is possible that the male gives no mutation. In those rare cases you would end up with a male baby that is split to whatever mutation the mother was carrying. As is the case in table 10 that male would be split to Cinnamon. The only difference in table 11 is that the mother is a Yellow-side. Does not really effect the outcome much except the visual male that is split to Pineapple would be visual Yellow-side and the split male would be split to Yellow-side. It is even possible to pair a Double split male with a Normal GreenCheeked hen and get a Pineapple hen baby. Those results are seen in table 12. There are some real problems with this pairing just like we had discussed in the previous section on Splits. Most all the male babies would be Splits. They would either be Split to Cinnamon, Yellow-sided, Pineapple or nothing. The problem with that is that they would all look like Normal GreenCheeked. They only way you could tell is to breed them with a know mutation and see what the results were to tell what they were Split to. This is a possible pairing but not very advisable. Now the females from this pairing would not be a problem at all. You would get about 50% visual Cinnamon’s and the majority of the remaining hens would be visual Yellow-sided hens. Somewhere around 10% of the Crossover would happened and you would get a Pineapple hen. Keep in mind there is still that remote chance of no mutation passing and you might get a Normal hen. This is not very probable but is statistically possible.We have now covered the most common ways to breed for a female Pineapple. Unless you just buy a Pineapple outright you will need a little patients and some understanding. It will or could take a clutch or two before you actually get a Pineapple hen baby.

So how do we get a male Pineapple? There are several ways. We can pair a Double Split male with a female Pineapple and hope for the ‘Crossover’ to happen. We can pair a male that is split to Pineapple male with a female Pineapple and get far better results. As we discussed in the previous section covering splits, when you pair a split with a visual your resulting offspring carries a much higher percentage of the desired mutation. Lets look at some tables and see how that works out.

	Y	Xys-cin
Xcin	YXcin	Xcin Xys-cin
Xys	YXys	Xys Xys-cin
Crossover	YXys-cin	Xys-cin Xys-cin
No Mutation	YX	XXys-cin

Table 13

	Y	Xys-cin			Y	Xys-cin
Xcin YXcin	Xcin Xys-cin		Xys YXys	XysXys-cin
Xys-cin YXys-cin	Xys-cin Xys-cin		Xys-cin YXys-cin	Xys-cin Xys-cin

Table 14 Table 15

	Y	Xys-cin			Y	Xys-cin
Xys-cin YXys-cin	Xys-cin Xys-cin		X YX	XXys-cin
Xys-cin YXys-cin	Xys-cin Xys-cin		Xys-cin YXys-cin	Xys-cin Xys-cin

Table 16 Table 17In Table 13 we paired a Double Split male with a Pineapple hen. The female babies will be split almost 50% visual Cinnamon and 50% Yellow-sided. As stated above when the Crossover happens you still will get Pineapple hens about 10% of the time just the same as we did in the above tables 10 thru 12. Now the males will be a little different. Since the hen in this pair is a Pineapple she already has the combined mutation gene. That will be passed to all the male babies. All of her male babies will be split to Pineapple. This is because the hen is giving one of the X chromosomes and the male gives the other X chromosome. So, the male babies with either be Cinnamon split YellowSided or YellowSided split Cinnamon. Once again, if the Crossover happens in those 10% of the cases you will get a full visual male Pineapple. We can’t forget that remote possibility of the male not passing on any mutation. In those rare cases the female babies will be normal and the males will look normal but will be split to Pineapple.

Now let’s look at tables 14 and 15. These are pairings of either a Cinnamon split YellowSided or a Cinnamon split Yellow-side male paired with Pineapple hens. I am not going to cover each table but will cover them in general. The results are very similar in that 50% of all the hen babies will be Pineapples and 50% of all the male babies will Pineapples. This is very similar to the results that were discussed in detail when we covered Splits earlier. The only difference in these two males is what his visual colour is. In table 14 he is split to Cinnamon. That split then effects the remaining visually babies. The remaining 50% of the hens will be Cinnamon and the other 50% of the male babies will be Cinnamon split Yellow-side. The same results apply to table 15 except that instead of being Cinnamon they will be Yellow-sided. The only exception is Table 17. The male in this case is a Normal looking male that is split to Pineapple. In that case the remaining 50% hens will be normal and the remaining 50% males will be just split to Pineapple.

A TWIST TO THE PINEAPPLE MUTATION

An interesting phenomenon can, will and has been observed with the combined mutation known as Pineapple. Even though both mutations are present on a single ‘X’ chromosome they are separated by a fairly large distance on the gene (relatively speaking). What this means is that they are very loosely bound to each other, if at all. What has happened and been observed is that the babies of a Split Pineapple male may not always have both mutation genes. The Split Male Pineapple parent may only pass on either the Yellow-sided mutation or the Cinnamon mutation or neither. It is not a given that the combined mutation will be passed on to the offspring. What this really means is that it just complicates the whole picture. Here are some charts to explain what I mean and these are by no means the only combinations. Use them for a reference. What we have learned is that Visual Pineapples will breed true to colour. This means if both parents are full visuals all the babies will be visual Pineapple babies. But if the father is not a visual Pineapple the mutation will come apart. The best way to describe this is since there are 4 mutation locations available in the male, if all 4 locations, 2 Cinnamon & 2 Yellow-sided, are not occupied the mutations will move around or jump. Lets go back a bit. I had talked about Cinnamon split YellowSided and YellowSided split Cinnamon. Tables 18 and 19 show how you breed for those.

	Y	Xys-cin			Y	Xys-cin
Xcin YXcin	Xcin Xys-cin		Xys YXys	Xys Xys-cin
Xcin YXcin	Xcin Xys-cin		Xys YXys	Xys Xys-cin

Table 18 Table 19In table 18 a male Cinnamon is paired with a Pineapple hen. You see that you get only Cinnamon hens. On the male side the offspring you get will be Cinnamon split Yellow-side. They are also some times called Limes or even Cinnamon split Pineapple. We have settled on Cinnamon split Yellow-side since that is genetically what they are and best describes these males. Table 19 has very similar results except the females are visual Yellow-side. Likewise the males are Yellow-side split Cinnamon. The usefulness of these males in breeding for Pineapple males is equal. It really comes down to what mutation you prefer the non Pineapples to be. Personally I lean towards YellowSided, but that is just my preference.

Let me get back to what I was explaining about the mutations being loosely bond. Lets take a YellowSided split Cinnamon for example. As stated earlier there are 4 locations open. In a Yellow-sided split Cinnamon only 3 of the 4 location are filled or occupied. This allows the Cinnamon to move back and forth between the two ‘X’ Chromosomes. In the example we are using that really does not matter since the male is a visual yellow-side.

	Y	Xys-cin			Y	Xys-cin
Xcin	YXcin	Xcin Xcin		Xys	YXys	Xys Xys
Xcin-ys	YXcin-ys	Xys-cin Xys-cin		Xys-cin	YXys-cin	Xys-cin Xys-cin

Table 20 Table 21 Lets look at Table 21 for example. This is a Yellow-side split Cinnamon Male paired with a Pineapple hen. As I was explaining earlier, even if the Cinnamon mutation moves, because there is no Cinnamon mutation on the other ‘X’ chromosome to hold it in place the results are the same. 50% of the babies are Pineapple, both male and female, and 50% of the babies are Yellow-side, both male and female.As a side note, I personally prefer using these males in my breeding programs over the use of a Double Split male. Here is why. When using a YellowSided split Cinnamon or a Cinnamon split YellowSided male first you don’t have to wait for the ‘Cross-over’ to happen. It already is present. Also you get no ‘Normal’ or Green babies that you have no ideal what they are genetically.

Now let’s look an example where the Pineapple mutation can split apart. Remember how we were talking about the 4 mutation locations on the ‘X’ chromosome? What if only 2 of the 4 were occupied? This would then allow both the Yellow-side and the Cinnamon to move between the two ‘X’ chromosomes freely since there was nothing to hold either of them in there current location.

	Y	Xys
X	YX	Xys X
Xys-cin	YXys-cin	Xys Xys-cin
Mutation Splits	YXys	Xys Xys
Mutation Splits	YXcin	XysXcin
No Mutation	YX	Xys X

Table 22If you look at Table 22 there is a Normal split Pineapple male paired with a Yellow-sided hen. As I was describing earlier, if both mutations are on a single chromosome, and there is no mutation on the other chromosome to hold the mutation in place it is free to move or unbind. The results are shown in Table 22. This became very apparent in breeding for Blue mutations. Here is a teaser about breeding Blue Mutations and combining Blue with Sex Linked Mutations:The first step is to create a Triple Split male. This was done by breeding a Male Blue to Pineapple hen for example. Since Blue is a recessive mutation and the bird is ‘Normal’ as far as Sex Linked mutations are concerned you end up with males that are Normal split Pineapple split Blue. The hens would be just Normal split Blue. If by chance you have a Male Pineapple and a Female Blue around that is a much better pairing. The babies would be: All the males are Normal split Pineapple split Blue and the hens would be Pineapple split Blue. Now if you take this Triple Split male and breed him to a Blue hen you will find that the Pineapple mutation in him will come apart. You will get Normal Hens, YellowSided Hens, Cinnamon Hens and Pineapple hens. As far as the males are concerned, they will all just be splits and will either be Blue or split Blue. The cool part is that since he is split Blue and the Hen is Blue those hen babies can and will be Blue as well or at least split to Blue. This pairing is a great way to start you Blue/Sex Link combination program. It is almost like Christmas with each clutch. As they start to feather you will get a new present with each new colour combination you get. The combinations are many. If you want to bread for a specific colour that can be targeted by changing the Hen.As we learn more thru breeding and documenting the results I will make every effort to update this document. I personally did not fully expect that the Pineapple combined mutation would separate the way that it is being seen. So please consider this a working document that will change as new facts are found and understood about these wonderful mutations. In closing I hope that this has helped to explain mutations and give you a better understanding of three of the most common GreenCheeked mutations available in the UK today. There are probably other combinations that you could use but these are some of the most common. I just wanted to cover these examples to give a beginning looking into the exciting topic of GreenCheeked mutations.

For a teaser let’s complicate this whole thing by throwing in the Blue mutation. What about Blue Cinnamon or Blue YellowSided, or how about Blue Pineapple . Wonder how those would be. Blue is totally different in that it is not sex linked it is recessive.

 

Blue YellowSided

Blue Cinnamon