How do genetics work?

[talkinboutchickens]

I have always wanted to hatch my own chicks, but know how they would look when they will grow up.
I have been researching chicken genetics, but they are SO COMPLICATED and hard to understand.
I was wondering if anyone can tell me basic genetics in simple terms and words????

 

[CloneFly]

I have always wanted to hatch my own chicks, but know how they would look when they will grow up.
I have been researching chicken genetics, but they are SO COMPLICATED and hard to understand.
I was wondering if anyone can tell me basic genetics in simple terms and words????

 

[Chicks n stuff]

I personally love chicken color genetics. I suppose the first thing you should learn about is the foundation colors.
The foundation color of any chicken is determined by the 10 E locus series base colors. Poultry Genetics.
The E locus genes, in order of most dominant to most recessive. Genes:

1. E(dominant black/extended black)- examples of this base color can be found in many breeds, from the black Australorp to the white crested black polish. Dominant black is very common. But every black chicken is NOT dominant black, and dominant black chickens aren't always black either, for example my paint silkies are E-dominant black, but they appear mostly white thanks to I-dominant white. There are also black dilutions; Bl-blue, lav-lavender, choc-chocolate. Furthermore two copies of c-recessive white covers black and red pigment. Also, while E-dominant black hens are usually free of color leakage, males are the other hand will commonly have red, gold, or silver leakage on their necks, shoulders, and/or body feathers. Chickens that are solid black without any leakage were selectively bred to avoid color leakage, and black based chickens commonly have black enhancers.

As for black chickens that aren't dominant black, a birchen with a Ml-Melanotic gene appears solid black, as is seen in the FBC Marans, which is why Some FBC Marans are completely black. Note that many FBC Marans blood lines were also mixed with black Marans, so some FBC Marans flocks are actually a mix of ER-birchen and E-dominant black and Ml-melanotic. However, the FBC Marans aren't supposed to be dominant black, but you can't tell the difference between a E-dominant black bird and a ER-birchen + Ml-melanotic bird that appears all black, so it would be hard to enforce the idea that E-dominant black shouldn't be allowed in FBC Marans lines, when, Ml-melanotic is considered to be a trait of the breed variety, and it would be hard to breed out the E-dominant black and leave the Ml- melanotic gene. As they are both dominant and it could be hard to distinguish between the two. Another black enhancer that can make a birchen base bird appear solid black is cha(charcoal).

2. ER(birchen), FBC Marans are considered to be red birchen, but there are many breeds that are birchen that better represent this base color, birchen Cochins are a good example. Birchen chick down is similar to a E-dominant black chicks down, birchen chicks are usually mostly black with a few white or off-white spots on their wings and under belly. Birchen is a common color.

3. ER- Fay(fayoumi birchen), as possibly seen in the silver and gold Egyptian Fayoumi chicken, the Egyptian Fayoumi has many alleles contributing to their appearance besides their base color, they possess pattern genes that give them autosomal barring, those genes being Db Darkbrown and Pg pattern gene. The chick down of the ER-Fay is supposed to be red-brown. This is a rare base color.

4. eWh(dominant Wheaten), think salmon faverolles, they are eWh-dominant wheaten, and they are a excellent example for this base color as the salmon faverolle doesn't have many other feather genes at play, therefore you can really observe the difference in chick down, dominant wheaten chick down is a light cream color, and while adult plumage on hens is usually are a buff or beige color, an adult dominant wheaten rooster has a similar appearance compared to other base colors, such as e+, eb, and ER.

5. e+(duckwing/wild type), the welsummer is the poster child for duckwing, Welsummers are a red duckwing. Side note; in American we commonly call duckwing partridge. So commonly it's called partridge instead of duckwing that you may think of "partridge" as meaning American Partridge, also in America we call eb-"European"-partridge, brown, and for some reason we also refer to duckwing as brown and light brown. e+ duckwing is the original base color, the red jungle fowl is gold duckwing. Duckwing is a common color, to tell the difference between e+ and eb you can look at chick down on birds that Aren't carrying other genes that cause changes in chick down, or you can tell by looking at adult females, e+ hens will have what is called a salmon breast, and eb hens chest will be a similar color brown as the rest of their body. The chick down of e+duckwing chicks, they have very uniform stripes, males will have lighter stripes and females will appear to be wearing winged eyeliner. Homozygous e+duckwing chicks can be sexed by looking at their chick down, the accuracy can be as good as 95%, but unlike the welsummer, not all duckwing based breed verities have been bred for their auto sexing potential, therefore the accuracy of sexing chicks is not going to be as good.

6. eb(partridge/brown), fun fact; brown leghorns most commonly come in e+-duckwing, they can also be actual brown, eb-brown birds will Not have a salmon colored breast feathers on the hens. The eb roosters will look exactly the same the e+ roosters, almost identical. eb-partridge brown leghorns are usually marketed as dark brown leghorns. Partridge/brown is a common color. I have many eb-partridge silkies. A lot of Easter eggers are eb-partridge as well. A eb-partridge chick without any other genes that affect chick down will look chocolate in color, with no stripes or very faint stripes. However many breeds that are eb-partridge carry pattern genes that can cause multiple variations of stripes on the chick down. It should also be noted that, the pattern gene Pg(pattern gene), will Not change eb(partridge) based roosters' juvenile and adult plumage. Currently most eb-partridge based breed varieties have pattern genes, for example the partridge rock is double laced. Ml-melanotic + Pg-Pattern gene = double laced, but this lacing will only show on the females, not the males. Furthermore eb-partridge does Not have auto sexing potential.

7. es(speckled), so I have never seen a es(speckled) base color chicken, to my knowledge any way. If anyone can prove this base color is in fact real, that would be pretty cool. All I know is that es(speckled) was used as a description for the base color for chickens in a study on chicken color genetics, so it's generally assumed that they were seeing some new traits, that they are certain are linked to their base color genes. But I can't find any descriptions of the color, so either it's rare or maybe it's very similar to another base color. One might assume that the color being called speckled would indicate that this particular E locus mutation either causes some form of speckling on the bird, or that this base color has some sort of effect on mo(mottled), or Db(Darkbrown) + Ml(Melanotic) + Pg(Pattern gene) = spangled. But this is just speculation as I can't find any real evidence that this base color exists.

8. ebc(buttercup), I can't tell the midfielder genes from the differences in the E locus mutation, but the Sicillian Buttercup is ebc-buttercup. The adult plumage does look pretty similar to most other base colors that have autosomal barring. ebc-buttercup's distinctive difference from other E locus base colors is, the differences seen in the chick down. Buttercup is a rare color.

9. ey(recessive wheaton), recessive wheaton is generally accepted to exist. But no modern breed claims to be exclusively recessive wheaton. As far as I know, the only way to tell the difference between eWh(dominant Wheaten), and ey(recessive wheaten) is though breeding. Dominant Wheaton is only recessive to dominant black and birchen, whereas recessive wheaten is recessive to either all other base colors, except, perhaps recessive, Wheaton might not be recessive to eq(queen Silvia). It is to my understanding that a recessive wheaton has not been crossed to a queen Silvia, and therefore it is not known which of the two would be expressed phenotypically. Supposedly the chick down of recessive wheaten is different from dominant wheaten as well. Recessive wheaten is considered rare.

10. eq(queen Silvia), The Queen Silvia chicken was developed by Swedish geneticist Martin Silverudd the name choice was to honor Sweden's longest reigning queen, Silvia. This is another breed that has pattern genes, among other feather color modifiers, this breed also has autosomal barring. I don't know how eq-queen Silvia differs from other E series base colors. Queen Silvia as a breed is rare and so there aren't many opportunities for getting a queen Silvia chicken, so I don't have any firsthand experience with this base color. This is a very rare base color.

 

[Chicks n stuff]

You should really only focus on five of the ten known foundation colors as the other five are pretty rare.
E(dominant black) most black chickens are dominant black.

ER(birchen), common foundation color, several breeds of chicken have a birchen based color variation.

eWh(dominant wheaten), this a common foundation color, both the Rhode Island Red and New Hampshire Red are Wheaten based. But the RIR and NHR have many other color genes contributing to their appearance, I highly recommend looking at the salmon faverolle if you want to see this foundation color.

e+(duckwing), common foundation color. The Welsummer, bantam Welsummer, Welbar, Cream Legbar, Bielefelder, Crele Penedesenca, 55 flowery hen, crele old English bantam and many BB Red color variants are duckwing.

eb(partridge), common foundation color, most commonly accompanied by pattern genes. To best view this foundation color I recommend looking at the dark brown leghorn, the hen has a lack of a salmon breast, otherwise the color is very similar to e+(duckwing).

 

[Chicks n stuff]

Female chickens have a Z sex chromosome and a W sex chromosome. Male chickens have two ZZ sex chromosomes.



Autosomal basically means NOT sexlinked.



Sexlinked means that the gene is on one of the sex chromosomes. Spoiler! Currently all the known sexlinked chicken color genes on the Z sex chromosome.



Gold v.s. Silver

S(Silver) is a sexlinked, incomplete dominant gene, s+(gold) is a sexlinked, recessive gene, gold is the absence of silver, s+ is gold, S is silver. Silver is not a gold dilution or inhibitor. Silver is a mutation of gold, silver and gold are the same gene, silver is the mutated form of gold. If the Z sex chromosome has a S(silver) gene then it doesn't have a s+(gold) gene. Think of silver and gold as being two different sides of the same coin. A more accurate analogy would be, think of the chromosome as a city, and the locus is the exact address of a one gene apartment, only one type of gene can live there, and only one gene can live there, there can only be a s+(gold) or a S(silver) on the gold/silver locus of a Z chromosome. That said, a rooster has two Z sex chromosomes and therefore can have a s+(gold) gene on one Z sex chromosome and a S(silver) gene on the other. Hens, however, have only one Z sex chromosome and therefore can only ever be silver or gold.

 

[Chicks n stuff]

Gold diluters/gold inhibitors:

Di(dilute)- autosomal, dominant gene. Lightens gold.



ig(inhibitor of gold/lemon/cream) - autosomal, recessive gene. Lightens gold, however the results of this gene vary widely from individual to individual. The amount of change this gene causes to the gold of a particular chicken seems to be random.



Cb(Champagne blond) - autosomal, dominant gene. Lightens gold.



lav(lavender)- autosomal, recessive gene. Lightens gold and black. Lightens gold to a cream color.



Gold enhancer:

Mh(mahogany/red)- autosomal, dominant gene. Darkens gold.

 

[Chicks n stuff]

Black enhancers:

Ml(Melanotic/melanised)-autosomal, dominant gene.



cha(charcoal/melanised)-autosomal, recessive gene.



Black diluters:

Bl(blue)- autosomal, incomplete dominant gene. One copy lightens black to grey, while two copies lighten black to white/pale grey with flecks of gray.



lav(lavender)- autosomal, recessive gene. Lightens black and gold. Lightens black to a light gray.



choc(chocolate) - sexlinked; found on the Z sex chromosome, recessive gene. Lightens black to a dark brown.

 

[Chicks n stuff]

White:

I(dominant white/inhibitor of black)- autosomal, incomplete dominant gene. One copy removes most black, two copies remove all black, it can also lightens gold.



c(colorless/recessive white) - autosomal, recessive gene.



White stripes:

B(Barring/cuckoo)- sexlinked; found on the Z sex chromosome, incomplete dominant.



White spots or white spots accompanied by and attached to black spots:

mo(mottled)- autosomal, recessive gene.

 

[Chicks n stuff]

Auto sexing chickens.

First and foremost auto sexing implies generational stability, in the accuracy of sexing chicks, aka, being able to see constant differences in male and female chick down throughout the generations.

Sex linked on the other hand gives you a single generation of chicks that can be sexed by looking at the chick down. A sexlinked chicken does Not breed true, an auto sexing chicken does.



Genes that have auto sexing potential:



e+(duckwing/wild type) is a E series base color that has auto sexing properties. The female chick down has darker stripes and looks to be wearing black eyeliner.



ig(cream) is a gold inhibitor. It lightens the chick down of male chicks.



B(sexlinked barring/cuckoo) is a gene mutation that causes white stripes on the feathers of the birds carrying this gene. This gene has both auto sexing and sexlink potential. It is a sexlinked gene, which is carried on the Z sex chromosome, as female chickens are ZW they can only ever be hemizygous, whereas males can be homozygous or heterozygous as they two Z sex chromosomes. Males that are homozygous for sexlinked barring will have a larger white head spot and be lighter in color than their hemizygous female counterpart.



The cream legbar is an auto sexing breed that's foundation color is e+(duckwing), they have the gold inhibitor ig(cream), and they have the sexlinked barring B(barring/cuckoo). Cream legbars are very easy to sex.

 

[Chicks n stuff]

Sexlinked pairings:



Homozygous s+(gold) rooster paired with a S(silver) hen.



Solid colored rooster paired with a B(sexlinked barring/cuckoo) hen.



choc(sexlinked chocolate) rooster paired with solid colored hens.