Talk Budgies Forums banner
Status
Not open for further replies.
1 - 15 of 15 Posts

·
Member of the Month
Joined
·
3,184 Posts
Discussion Starter · #1 ·
Okay. This will be a little long, but I am so cunfused and the background is necessary so...here we go. :D

A while back, I bred Malcolm ( a light green dom pied male) with Bette ( a sky blue normal hen). They've had 2 clutches for me. I got all sky blues and light greens, half dominant pieds. ALL of the sky blue babies were YF. The assumption was made that Bette must be DF YF type 1 as those birds look like a normal sky blue, but give 100% YF babies.

Purl (opaline violet cobalt greywing) has had 2 clutches as well - one with Bruce (YF2 opaline greywing rec. pied) and one with Kiwi (YF2 sky blue). With Bruce we got 100% opaline greywings - some normals, some RP, and some YF. With Kiwi, we got normals and RP, some with YF.

NOW, Purl and Malcolm have 5 chicks - 2 greens, 3 blues.

1 looks like a greywing and RP - so Mal must be split to greywing and RP
1 dom pied. No surprise there.
1 normal green. No surprise there.
1 normal blue. No surprise there.
The 4th chick is pied, and I think RP, but I'm still not sure about that and green. No biggie.

Finally we get to the surprising part. ALL blue series chicks are YF. Just like when Bette was with Mal. The YF can't come from Purl because she has been paired with 2 YF males and has produced non YF babies.

The only explanation is that it's from Malcolm and he carries 2 copies of the YF gene. I'm confused because I DF yf blue and his dad a green bird, would he have a SF YF gene connected to his blue gene and it just so happens that all of his blue chicks got the YF gene? Or maybe his mom was DF yF and his dad was from a DF YF hen and a normal male which would mean he'd have to inherit 2 copies of YF and then all of his blue chicks would be YF???

:so confused:

Any body know? Thanks!
 

·
Member of the Month March 2011
Joined
·
19,551 Posts
While he could be a Df yellowface from his parents description, he could just as easily be a sf :)

The thing about sf is that while when you look at hundreds of chicks about half of them inherit the gene, but on an individual clutch basis you can get 100% sf chicks or 100% normal chicks in a clutch.

Take for example one of my albino hens Opal, who is masking sf grey. She has had 4 clutches of chicks with 3 different cocks. The first 2 clutches were with Zest a light green male spangle and all of the 9 chicks grey so I figured she must be a df grey. Assuming I was going to get all grey chicks I paired her to Tiki my grey df dominant pied male. They had 7 chicks, and after the first 3 came out grey I was shocked that the next 3 were blue! I had figured for sure that she was a DF having so many greys, but nope! It was just a roll of the genetic dice and grey won every time until then lol.

In total she has had 24 chicks from those 4 clutches, and 18 have been grey with only 6 blues :laughing:

So bottom line especially since some of his chicks are going to be green... keep an eye out because he could be either unless proved otherwise :D
 

·
Member of the Month
Joined
·
3,184 Posts
Discussion Starter · #3 ·
Ok sooo...a green bird can carry the YF gene?

And I just made up his parentage as an example. I have no idea what his parents were.
 

·
Registered
Joined
·
96 Posts


Yes, a green bird can definitely be masking any form of yellowface in sf or df :) And my bad I got confused somewhere then :p
Maybe I can be of some help. :) Lindsey's statement above is untrue. (Sorry Lindsey)

People get confused when they think that the yellowface mutation is a separate gene from green and blue. In fact, it is not. It is what is called an "allelomorph", meaning that the same gene has morphed, or mutated, in two different ways.

First the green gene mutated into blue. Then it mutated again, and again, into the several yellowface mutations. All 5 of these genes, the green, the goldenface, the yf2, the yf1 and the blue, are all found on the same locus of the chromosome. (The locus is like the address, the exact place on the chromosome where the gene is always located.)

Since chromosomes come in pairs, each budgie has two copies of the gene for that locus. This can also be phrased as "each budgie has two alleles."

There are 5 types of alleles that fit on that locus, but each bird can only have two of them. (A pair, one from the father and one from the mother.)

Now here is the part that trips people up: A green bird can be split to blue, so it has one green allele and one blue allele. But a green bird can also be split to yellowface, and have one green allele, and one yellowface allele.

But a green bird cannot be split to blue, and also be single factor yellowface. That would give it three copies of the same gene. Likewise, a green bird cannot be split to blue AND double factor yellowface, or then it would have four copies of the same gene.

A budgie can be any combination of 2 alleles from any of those 5 allelomorphs. So there can be green budgies split to yellowface 2, green budgies split to goldenface, Goldenface budgies split to yellowface 1, etc.

They can be combined in every possible combination of two, and there IS a set order of dominance between them all. (That's another discussion :p)

The offspring your green bird has produced is consistent with it being a green bird split to yellowface.

I hope this has helped. I'm sorry about the technical terms, but it's hard to talk about genetics without using them. :)
 

·
Member of the Month March 2011
Joined
·
19,551 Posts


Maybe I can be of some help. :) Lindsey's statement above is untrue. (Sorry Lindsey)

People get confused when they think that the yellowface mutation is a separate gene from green and blue. In fact, it is not. It is what is called an "allelomorph", meaning that the same gene has morphed, or mutated, in two different ways.

First the green gene mutated into blue. Then it mutated again, and again, into the several yellowface mutations. All 5 of these genes, the green, the goldenface, the yf2, the yf1 and the blue, are all found on the same locus of the chromosome. (The locus is like the address, the exact place on the chromosome where the gene is always located.)

Since chromosomes come in pairs, each budgie has two copies of the gene for that locus. This can also be phrased as "each budgie has two alleles."

There are 5 types of alleles that fit on that locus, but each bird can only have two of them. (A pair, one from the father and one from the mother.)

Now here is the part that trips people up: A green bird can be split to blue, so it has one green allele and one blue allele. But a green bird can also be split to yellowface, and have one green allele, and one yellowface allele.

But a green bird cannot be split to blue, and also be single factor yellowface. That would give it three copies of the same gene. Likewise, a green bird cannot be split to blue AND double factor yellowface, or then it would have four copies of the same gene.

A budgie can be any combination of 2 alleles from any of those 5 allelomorphs. So there can be green budgies split to yellowface 2, green budgies split to goldenface, Goldenface budgies split to yellowface 1, etc.

They can be combined in every possible combination of two, and there IS a set order of dominance between them all. (That's another discussion :p)

The offspring your green bird has produced is consistent with it being a green bird split to yellowface.

I hope this has helped. I'm sorry about the technical terms, but it's hard to talk about genetics without using them. :)
The term "masking" is not technically corrct, but it is complicated explaining that yellowface is a split when it behaves as a dominant gene with blue so I did not go there :p

But a green bird cannot be split to blue, and also be single factor yellowface.
The offspring your green bird has produced is consistent with it being a green bird split to yellowface.
These 2 statements contradict each other it seems :) If a green could not be split for both yellowface and blue, then it would be impossible for Erin to have yellowface blue chicks from a green parent? :)

And for that matter if all 5 of these are on the same chromosomes with only 2 being able to be present at any given time, would that not make a df yellowface blue impossible as well with it being 3 genes? There must be some kind of exception, or is it because the yellow face gene itself is split for blue making it basically 2 genes..
 

·
Member of the Month
Joined
·
3,184 Posts
Discussion Starter · #9 ·


These 2 statements contradict each other it seems :) If a green could not be split for both yellowface and blue, then it would be impossible for Erin to have yellowface blue chicks from a green parent? :)

And for that matter if all 5 of these are on the same chromosomes with only 2 being able to be present at any given time, would that not make a df yellowface blue impossible as well with it being 3 genes? There must be some kind of exception, or is it because the yellow face gene itself is split for blue making it basically 2 genes..
I agree. How could I get a yf blue?

And, thanks for all that info. It's a lot to wrap my head around, but I appreciate it.
 

·
Registered
Joined
·
96 Posts
I'm sorry that this is going to be long. Genetics is a pretty complicated subject, and if it could be explained in a few short sentences, then we wouldn't need nerds. :p

I think some of the confusion lays with the terminology that is commonly used. And that terminology was started by the breeders who first discovered yellowface, because they thought that green mutated to blue (correct), and then some other mutation came along that added some yellow back to the blue bird (incorrect). So they thought that this second mutation could only be seen if the bird was blue first, and that if a green bird had the special new mutation, it would be masked by the green's natural color.

What they didn't realize, but which has been proven and is accepted now, is that all the yellowfaces and the blues are a "failure to produce yellow" mutation, and they all lie on the same locus that codes for yellow pigment.

So they didn't give the yellowface series its own color shade names for the dark factors. They just used the blue names (sky, cobalt and mauve). That's why people get confused, because they think they actually have a sky blue bird or a cobalt bird (homozygous for the blue gene) to start with.

Lindsey hit the nail on the head when she said a single factor yellow face is a yellowface split to blue. And yes, that makes it basically two genes, because genes come in pairs. It has one gene for yellowface and one gene for blue, and nothing else at all.

I don't want to muddy the waters, but if you understand how the dilution genes work, which turn regular black wing markings to different shades of grey, that is another example of multiple allelomorphs on the same locus, and the green-yellowface-blue series works in exactly the same way.

In the greywing gene, it is the gene that codes for melanin production that gets damaged, and fails to produce full levels of melanin. How much damage there is to the gene determines how dark or light the birds markings will be.

It's the same with the yellowface-blue gene. There is damage to the gene that codes for yellow pigment. Depending on which level of breakage has occured, the bird will produce more or less yellow. In the case of blue, it can't produce any yellow at all.

In the normal wild type bird, the gene codes for full yellow production, which give us the normal green bird. It's a shame that the blue mutation appeared before the yellowface one. Because if yellowface had come first, the breeders would have said "Oh look, these birds have lost some of their ability to produce yellow. Let's call them part blue bodies". (Or whatever their imaginations might have come up with.) Then when the blue mutation would have finally shown up, they would have understood that now the same gene had broken all the way down, and was failing to produce any yellow at all. It would have made more sense to them if they had seen a gradual reduction in abillity to produce yellow, with birds becoming less yellow and more white.
 

·
Registered
Joined
·
96 Posts
Hey, I forgot to add that there is an order of dominance to the 5 allelomorphs.

Green is dominant over all of them. Next in dominance is Golden face, then yf2, then yf1. Those three all show a certain level of co-dominance with each other. Then last comes blue, which is completely recessive to all the others.

Since the yellowfaces are in the middle, they are dominant over blue, which is what people usually talk about. But note that the yellowfaces, being in the middle, are recessive to green.

Green > GF > yf2> yf1 > blue
 

·
Member of the Month January 2009
Joined
·
3,676 Posts
In the past it was thought that green birds could mask yellow face but as Budgiedin has explained it is more correct to say that green can be split for yellow face. Because blue and yellow face both come from the same genes a green bird can't be split for both at the same time.
(This works the same way as greywing, clearwing & dilute are carried by a normal)

A green bird that is carrying a yellow face gene mated to a blue bird will only produce green or yellow face blue chicks. You can not get a white faced blue from this pairing. Therefore the results you got from Malcolm are exactly what would be expected
 

·
Member of the Month
Joined
·
3,184 Posts
Discussion Starter · #13 ·
In the past it was thought that green birds could mask yellow face but as Budgiedin has explained it is more correct to say that green can be split for yellow face. Because blue and yellow face both come from the same genes a green bird can't be split for both at the same time.
(This works the same way as greywing, clearwing & dilute are carried by a normal)

A green bird that is carrying a yellow face gene mated to a blue bird will only produce green or yellow face blue chicks. You can not get a white faced blue from this pairing. Therefore the results you got from Malcolm are exactly what would be expected
Thanks, Nev. I know you and Budgiedin were saying the same thing, but, for whatever reason, I get it now. That is fascinating.
 

·
Registered
Joined
·
96 Posts
Ah, Neville! So this is where you've been hanging out! We've missed you over on that other place. (Which I'm not naming, because I'm not sure if that's allowed. :p )

-Finnie
 
1 - 15 of 15 Posts
Status
Not open for further replies.
Top