Guinea Fowl Genetics

[rollyard]

I found learning about colour genetics extremely difficult when I first started, still have problems, & know very little comparatively. Some understanding does make breeding for colour so much easier though, particularly when genes identified, mode of transmission understood, & the various mutation combination effects on plumage etc known. The issue I feel re: difficulty in understanding/identifying Guinea genes for colour/pattern is that most free range their birds making it impossible often to accurately assess what has gone into the mix in birds bred, especially when various colours/patterns kept. Keeping Guineas in small pens is no fun for the birds or keeper I don't think.

Info @ this Link for duck colours/patterns, but basic genetic rules apply for all birds!

Good Luck

 

[PeepsCA]

Um.. lol thanks?

 

[rollyard]

I have 100% confidence in your capabilities PeepsCA

 

[PeepsCA]

Quote:
I had a somewhat similar outcome last year out of eggs I incubated from a friend... she only had the one pair of Guineas, the Hen was either a Porcelain or an Opaline, (I could not get close enough to the Hen to get a good look or good pic of her the couple of times I had a chance to actually see her, but either way she was carrying both the buff/tan and blue genes), and the male was a Jumbo Pearl Grey... of course the hatches were mostly Pearl Grey, and a few Royal Purples, but I did hatch 7 identical Browns and 3 identical Chocolates... and all 10 were Hens. So to me it appears the buff/tan factor was definitely sex linked in this case.

 

[PeepsCA]

Quote:
I don't, I started reading and got a head ache, lol but Thanks

 

[rollyard]

The breeding system you have described is good I feel for testing Guinea colours because having only one pair of birds means that there is no/little risk of accidental contamination from other birds if/when free ranging, the natural way to go, & egg collection/storage.

If the factor for buff/brown (d) is on the Z chromosome & recessive, then the ten brown/buff female progeny must have inherited the gene from their father (being Pearl Grey would make him D+/d @ the locus for buff/brown), because they (female progeny) can't have inherited it from their mother whether she has it (d) or not! This would mean that if the mother also has it (d/- for her), then you could potentially get just as many male progeny influenced colour-wise by the gene, ie:-

25% males D+/d (not influenced by buff but one dose hidden)
25% males d/d (influenced by buff)
25% females D+/- (not influenced by buff)
25% females d/- (influenced by buff)

If autosomal mode of transmission, then same outcome, eg, D+/d male x d/d female equals:-

50% D+/d (not influenced by buff) both sexes
50% d/d (influenced by buff) both sexes

Maybe just the way factors segregated in this instance?

One other thing; Porcelain (not Porcelain whites) don't have self-blue dilution according to @ least one source, although photos of both Porcelain & Opaline that I have seen shows that they both do look to have it (blue dilution)?? Confusing!

Edited to remove edit

 

[PeepsCA]

I've only read some of your duck thread on genetics, and not much of it has sunk in yet (especially what the specific terms mean), so most of what you just typed is still over my head and looks like Greek or Chinese to me lol. You're going to have to dumb things wayyyy down to more simple terms for a while until I have a better understanding of it all, lol sorry.

There are several color charts on the net with horrible pics but decent descriptions of the Opaline and Porcelain colors (and several other colors that carry both the tan/buff and blue genes) explaining to what degree they display the dilution of the blue color... but just to confirm, over here they do display a diluted blue color to one degree or another. Exactly how/why they all carry both gene colors in their genetic makeup, I do not know/understand yet. I've been told these colors are good to have in your flock because they have the best probability of hatching a variety of both the blue and tan/buff colors, (depending on what hidden/recessive genes their mate is carrying of course). This past year I had several Lite Lavenders in my main breeding flock, and I'm going to guess they were responsible for most of the Porcelain and Opaline keets that I hatched... I of course can't prove it tho, since it's a mixed flock

Even tho it's kind of incomplete, this link that you referred to not that long ago has a table at the bottom of the page showing some/most of the colors that carry both the tan/buff and blue genes (if "carry" is even the correct term to use in this case), note that the author states the table "is only an educated guess as to what is going on" tho.


Unfortunately the breeding pair of my friend's that I incubated eggs from and hatched out the Brown and Chocolate Hens from is no longer alive. The male got hit by a car in the road towards the end of last year's breeding season(whihc if course made the Hen stop laying shortly after that), and then the Hen got taken by a predator before she started laying this year. I provided a new male for her (and they bonded), but the Hen got taken before the new breeding/laying season. I still have 11 offspring from the pair tho, 6 of the Brown Hens, the 3 Chocolate Hens, 1 Royal Purple Hen and 1 Royal Purple male. I had them all in a 10'x20' breeding pen this past breeding season with 2 other Royal Purple males and a Lavender male (from my other 2 unrelated flocks), but the penned flock did not produce too well for me. Even tho they were all raised together from keets on, it wasn't a happy environment for them being penned full time (I penned them to prevent the 10 Hens from being bred by my Pearl Grey and Royal Purple flock). The Lavender (Alpha) male picked on everybody and there was a lot of tension from his aggression in the pen all season long. All 10 Hens laid eggs regularly all season for me, but only 4-5 Hens laid fertile eggs off and on. So for next year's season Mr Lavender is gettin' the boot and replaced with a Coral Blue...

. (I'll probably take out the Royal Purple males too and maybe add one of my Buff males, and see how just the 2 new males works out). I had the Lavender in there for a reason tho, I specifically wanted some Coral Blue keets from that flock (so I'd have Coral Blues from 2 unrelated flocks for next year). And he did produce several of them for me, but I no longer need his services, lol.

 

[perchie.girl]

Quote:
OK Now I have some really Stoopid questions.

What do the - and + symbols represent
What is the significance of upper and lower case "d's" are they representing Dominant and recessive?

My brain is cracking..... All I know is what I was taught in high school..... Blue eyes are recessive and that if you get a blue eyed child out of two brown eyed parents they both have to carry the recessive gene. I have NO idea how that would be represented in the proper code or notation.

OK I looked up what Autosomal means and its very interesting indeed.

""If a trait is autosomal dominant, it means you only need to get the abnormal gene from one parent in order for you to inherit...."" (I replaced the word disease with the word Trait for clarity)

 

[rollyard]

Quote:
Yes, that sounds logical to me because they (Porcelain & Opaline) both have the two factors required to make self blue (Lavender) & buff/tan/brown. The Light Lavenders may have had the recessive genes for buff/tan/brown (omongst others), & if mated together (or other birds carrying hidden factors for both Lavender & buff/tan/brown, & partial spotting) could potentially produce some Porcelain & Opaline Guineas.

I had another look @ that link & yes I see that there Porcelain is said to have buff & blue factors; info can vary a little from one source to another, a bit like the colour charts I guess.

Unfortunate story about the Guineas but interesting. Also interesting about the penned birds; I have been meaning to ask how successful others have been breeding in confined areas? Thank you for info.

perchie.girl :

What do the - and + symbols represent
What is the significance of upper and lower case "d's" are they representing Dominant and recessive?

The negative symbol (-) represents no gene, so d/- tells us that one chromosome in the pair (usually come in pairs) have the gene for buff (d), while the "-" tells us that the other chromosome in the pair doesn't have a gene or form of the gene @ that locus (position).
The positive symbol (+) tells us that the gene is the original wild-type, or that found in the original coloured/typed organism, such as in this case, the wild Pearl Grey Guinea Fowl in Africa. So, D+ is the wild-type @ a particular locus on the chromosome, but @ some point in time a variation (mutation) of this factor occured that changed how the bird would look. Because it is another form of D+ @ the same locus (therefore an allele) & was found to be recessive in nature to its wild-type form D+ it was denoted d, so two doses required for it to express (be seen).

Yes, upper case means "more dominant to", but not always completely so. Examples, D+ is more dominant to its mutated allele d, so:
D+/D+ means the bird has two copies of wild-type @ the D locus, so wild-type trait designated for @ this locus is what we see;
D+/d means that the bird has one copy of wild-type & one copy of the recessive to wild-type mutated buff form d. In this instance the influence from the recessive d won't be seen, or @ least not fully, because its wild-type allele being more dominant will influence what we see moreso.
d/d means that the bird has two copies of the mutated gene @ this particular position (locus) on the pair of chromosomes. So in this case, d will influence what we see & buff will express. But sometimes expression can be altered/masked by other genes @ other loci in the mix. An example is Opaline colour said to be made of (probably amongst other things) both Lavender (l/l) & buff (d/d) mutations. Lavender influence appears to be epistatic (more influencial or dominant) to that of buff, so even though the Opaline bird is pure (has two copies) for both mutations we tend to see the Lavender influence colour-wise moreso. Theoretically, in combination the combined diluting power of l/l & d/d (d/- if on Z chromosome for females because they are genetically Zw) are thought to contribute to the lighter shade seen in Opalines.

Autosomal; Chromosomes are divided into either autosomal or sex-determining. Sex-determining chromosomes are denoted Z & w, while all others are autosomal. Therefore, genes on the sex-determining chromosomes are genes on the Z & w chromosomes, & it is these genes that can allow us to sex birds by colour (or some other trait) due to sex-linked trait expression in some instances.

Edited to correct the mistakes that you always notice after you have posted