Easy guide to genes and genetic symbols and terminology
So you have an interest in your birds, and you want to find out more about them. But you've asked a question and people have responded in jargon.
Firstly all genes that effect colour can do so in one of 3 ways. They can either enhance a colour, restrict or dilute a colour, or effect pattern.
Let's have a look at some of the common jargon, and what it means in plain english.
Firstly all genes that effect colour can do so in one of 3 ways. They can either enhance a colour, restrict or dilute a colour, or effect pattern.
Let's have a look at some of the common jargon, and what it means in plain english.
Wildtype
We have to start with something called "wild type" this is essentially a clean slate.
Wild type is a bird that has absolutely no genes that modify the feather colours, and would be how first fowl (Jungle fowl) appeared before we started breeding in variations.
Wild type is indicated in a gene as a "+" for example (pg+). Wherever the plus appears, it shows an absence of a modifier gene.
If a bird has one copy of the Columbian gene, it is written as Co/co+. You can see that the bird differs from the wild type by the gene that doesn't have the +, in this case Co.
So we use the lack of the + symbol to show which genes have been modified. This is an easy way for people to compare the genetics of various birds, to know how some people got a certain colour or pattern.
Wild type is a bird that has absolutely no genes that modify the feather colours, and would be how first fowl (Jungle fowl) appeared before we started breeding in variations.
Wild type is indicated in a gene as a "+" for example (pg+). Wherever the plus appears, it shows an absence of a modifier gene.
If a bird has one copy of the Columbian gene, it is written as Co/co+. You can see that the bird differs from the wild type by the gene that doesn't have the +, in this case Co.
So we use the lack of the + symbol to show which genes have been modified. This is an easy way for people to compare the genetics of various birds, to know how some people got a certain colour or pattern.
"Split" and gene pairs
As we have seen from the wild type section above genes are written in pairs, without going into too much detail, most genes that effect colour or pattern come in pairs, so a bird can have two copies of a gene.
The only major two differences are the gold or red gene, and the barring gene. Females can only carry one copy of these, that is why they are used in sex-linking breedings(more on that later).
So now that we have a basic understanding of wild type, let us look at how gene combinations are written down.
You may have seen the words heterozygous and homozygous floating around. Lets get a basic explanation for them.
So, homozygous, means that both genes in a pair are the same. (Co/Co), the birds has two copies of Co.
Heterozygous means that one of the genes in the pair is different. (Co/co+), the bird has one copy of Co and is missing one copy shown as co+.
The term "split" is also used, and means the same thing as heterozygous, split means it carries one copy of a certain gene. Something "split for Columbian"is also written Co/co+.
(As a side note, females can NEVER be split for any sex linked genes, they can never be split for gold, or split for barred, they either are or they are not)
Pretty easy when you look at it.
The only major two differences are the gold or red gene, and the barring gene. Females can only carry one copy of these, that is why they are used in sex-linking breedings(more on that later).
So now that we have a basic understanding of wild type, let us look at how gene combinations are written down.
You may have seen the words heterozygous and homozygous floating around. Lets get a basic explanation for them.
So, homozygous, means that both genes in a pair are the same. (Co/Co), the birds has two copies of Co.
Heterozygous means that one of the genes in the pair is different. (Co/co+), the bird has one copy of Co and is missing one copy shown as co+.
The term "split" is also used, and means the same thing as heterozygous, split means it carries one copy of a certain gene. Something "split for Columbian"is also written Co/co+.
(As a side note, females can NEVER be split for any sex linked genes, they can never be split for gold, or split for barred, they either are or they are not)
Pretty easy when you look at it.
Common Terms
Lets give a brief explanation of some other terms in bullet point.
(if you want an explanation of any other terms/genes or effects, then post a comment below!)
Dominant - This gene usually displays an action even if only one copy is present.(Patterning gene into this category)
Recessive - This gene will only display an effect if a bird has two copies (mottling falls into this category)
Phenotype - This is to describe how a chicken looks, and has nothing to do with the underlying genetics.*
Genotype - Genotype is which genes makes up a specific colour or variety. *
Melanisers - Genes are referred to as a melaniser, when they enhance black.
Leakage - The term leakage is used when a colour seeps through, or "leaks" into another colour. So a black bird with yellow or red patches on it is said to have leakage.
E-Locus - The E locus is a trickier one to explain easily. There are certain different foundations that birds are built on. These are commonly called backgrounds. For a more in depth look at the e-locus section.
Will add more when they come up.
A note about phenotype, while pehontype describes the look of a bird, it says nothing about the genes that make up that look. There can be any number of genotypes that make up a phenotype. Think about a black bird, there
are many genotypes(gene combinations) that make up the black phenotype.
(if you want an explanation of any other terms/genes or effects, then post a comment below!)
Dominant - This gene usually displays an action even if only one copy is present.(Patterning gene into this category)
Recessive - This gene will only display an effect if a bird has two copies (mottling falls into this category)
Phenotype - This is to describe how a chicken looks, and has nothing to do with the underlying genetics.*
Genotype - Genotype is which genes makes up a specific colour or variety. *
Melanisers - Genes are referred to as a melaniser, when they enhance black.
Leakage - The term leakage is used when a colour seeps through, or "leaks" into another colour. So a black bird with yellow or red patches on it is said to have leakage.
E-Locus - The E locus is a trickier one to explain easily. There are certain different foundations that birds are built on. These are commonly called backgrounds. For a more in depth look at the e-locus section.
Will add more when they come up.
A note about phenotype, while pehontype describes the look of a bird, it says nothing about the genes that make up that look. There can be any number of genotypes that make up a phenotype. Think about a black bird, there
are many genotypes(gene combinations) that make up the black phenotype.
Sex Linkage basics
Above we reffered to certain genes being sex linked. This means the males can carry two copies of a gene, and the females only one. Because genes can have a different
effect in one or two copies, we use them to make identifing males and females easier at day one.
Looking at a few examples.
A partridge male crossed to a silver pencilled female with give you sex linked offspring, the males will be yellow, the females red. This happens because males will get a copy of silver from the mother (S) AND a copy of red from the father(s+). The females will only get a copy of the colour from their father, so they will be red. The males will be a mixture of silver and red, and end up yellow.
This effect can be applied to any red based male, over a silver female.
The barring gene can also be used for sex linking offspring. if you cross a black male to a barred female, all the males from that cross will come out barred, all the females will be black. This is again because males can only pass a copy of barring onto their male offspring, and not the females in this breeding.
effect in one or two copies, we use them to make identifing males and females easier at day one.
Looking at a few examples.
A partridge male crossed to a silver pencilled female with give you sex linked offspring, the males will be yellow, the females red. This happens because males will get a copy of silver from the mother (S) AND a copy of red from the father(s+). The females will only get a copy of the colour from their father, so they will be red. The males will be a mixture of silver and red, and end up yellow.
This effect can be applied to any red based male, over a silver female.
The barring gene can also be used for sex linking offspring. if you cross a black male to a barred female, all the males from that cross will come out barred, all the females will be black. This is again because males can only pass a copy of barring onto their male offspring, and not the females in this breeding.
Double Breeding
Some breeders use a practice known as Double Breeding and i have seen this term confuse a lot of people.
Double breeding is basically having two separate "pens" or "lines" of birds, one to produce show quality males, and the other to produce show quality females. It is an odd thought that breeding show quality males to a show quality females wont always get you show quality offspring.
This happens due to Judging standards looking for things in a breed that cannot come from a single breeding pen. An example of this is the Partridge Wyandotte or Partridge Pekin.
Show quality males will come from breeding females who are more "mossy" and have less distinct pencilling in the feathers.
Show quality females come from males who have some spots coming through on their breast.
- To breed show quality males (full black breast) you use females that are not show quality.
- To breed show quality females (crisp distinct pencilling) you use males with a spotty breast that are not show quality.
To get a show quality male and female then, you need to separate breeding lines.
Double breeding is basically having two separate "pens" or "lines" of birds, one to produce show quality males, and the other to produce show quality females. It is an odd thought that breeding show quality males to a show quality females wont always get you show quality offspring.
This happens due to Judging standards looking for things in a breed that cannot come from a single breeding pen. An example of this is the Partridge Wyandotte or Partridge Pekin.
Show quality males will come from breeding females who are more "mossy" and have less distinct pencilling in the feathers.
Show quality females come from males who have some spots coming through on their breast.
- To breed show quality males (full black breast) you use females that are not show quality.
- To breed show quality females (crisp distinct pencilling) you use males with a spotty breast that are not show quality.
To get a show quality male and female then, you need to separate breeding lines.