The colors of Pugs are one of the most hotly contested issues on the internet, it is essential to have a conversation about how those colors are inherited genetically. There are a lot of individuals who don’t think it’s vital to know the information that’s on this page, but you may check it out if you’re interested. If you don’t have a clear picture in your head of what the different Pug coat colors look like, you should go to the Pug colors page first by clicking here.
It is difficult to write about genetics without first determining how much an individual already understands about the topic. Therefore, I’m going to begin with the fundamentals, and then I’ll expand from there. If you come across a part that contains information that you already possess, feel free to go on to the next one. Let’s start genes. They are there in all of us. Chromosomes are the fundamental building blocks that determine who we are, and genes are a component of chromosomes. Imagine a string of beads, with each bead representing a different gene, and the strand itself representing the chromosome. You get one gene from each of your parents, one from the mother and one from the father. The genes are what you inherit from your parents and they literally lie on the string in pairs. Because genes faithfully replicate themselves from one generation to the next, the offspring of any given individual will always have the same characteristics. A mutation is the condition that arises as an exception to this norm and describes the situation in which a gene fails to duplicate itself at some point in time. This is a rare occurrence in scientific terms.
The two genes that go together to form a pair will always be found clustered together at the same location on the chromosome. This is how we have learnt which genes are responsible for color, which are responsible for coat, which are responsible for muscular dystrophy, and so on. The single location at which the gene is expressed is referred to as the allele, and every given allele will include variants of the same genes. If the genes aren’t all the same type, one of them has to be the dominant one or the most important one at the same allele. For example, if you have a gene that determines whether you have red, blue, or green toenails, there has to be some sort of hierarchy in which one gene is more important than the others. If red is the dominant gene, then the toenail will be red even if the other gene at that allele is blue or green. This is because dominant genes always win out over recessive genes. This brings us to the concepts of the phenotype and the genotype. The characteristics of a dog that are manifest to the naked eye are referred to as the phenotypic. For instance, you can plainly see that the dog has red toenails. The dog has the traditional appearance of having red toenails. The real characteristics that are carried by the genes of the dog are referred to as its genotype. Therefore, if the sample from before has one gene for red toenails and one gene for blue toes, it carries the genes for both red and blue toenails, even if the only ones that are visible are the red ones. When discussing the alleles that a dog has, we often refer to them using a “shorthand” notation. For instance, if the color red is dominant, we would use the capital letter R. If a dog possesses both alleles for red toenails, the dog’s genetic makeup would be represented by the letters “RR,” which stand for two dominant red genes. If the dog in our example has one gene for red and one recessive gene for blue, the dog’s genetic makeup might be represented as “Rb,” with the “b” representing the dog’s recessive (non-dominant) blue nails. Easy, huh?
The fundamentals of fawn and black are equally as simple to understand. When referring to a pure, dominating black dog, you write BB, and when referring to a pure fawn, you write ff. The first thing that stands out is that the B’s are capitalized, whilst the f’s are lower case. This indicates that the black hue is a recessive trait in the fawn. Now, take note of the fact that I referred to “pure fawn” and “pure black” — if you mix fawns and blacks, the alleles for fawn and black will get confused with one another. The following table provides an overview of the genetic outcomes that may occur if a pure black and a pure fawn are bred together. The genes that come from the sire, or father, are represented by blue letters in the top row, while the genes that come from the dam, or mother, are represented by pink letters on the left side:
Ahah! Therefore, we now have a new group of dogs that are genetically distinct from the others: the hybrid blacks. These are dogs who will always have black coats due to the presence of the dominant black gene; nevertheless, they are also carriers of the fawn gene. When it comes to attempting to predict the colors of the puppies that will be born from a certain litter, this adds a TON of fresh information into the mix. Let’s add a third column to our table, which will be dedicated to the Hybrid Black Parent, and then observe the results:
Wow! It’s easy to become confused with colors, isn’t it? Especially if you have no idea if your Pug is all black, completely fawn, or a hybrid black coloration. Because the fawn gene is not dominant over the black gene in Pugs, you may be certain that if you have a fawn Pug, you have a pure fawn dog. If your Pug had even a single copy of the black gene, it would have the appearance of a black dog rather than a fawn.
This should pretty about cover all you need to know about Pug colors. You will see that there are NO genes indicated for brindles, NO genes indicated for spotted Pugs, and NO genes for any other color of dog save fawn or black. This is due to the fact that they are the only colors that are seen in purebred Pugs, regardless of what hues you see in a photograph of a Pug.
The Genes For Color – An Indepth Look
Continue reading this article if you are interested in finding out more about the origins of the various hues. The conversation will go on to cover brindle and spotted dogs, as well as other topics, but from here on out, it will get more technical. Because we are discussing more difficult subjects, this must be the case.
Because each allele is passed down from one of the parents, there is a fifty-fifty probability that the puppies will receive the same characteristics as their parents. The problem arises when the traits that are manifested (the phenotype) are not identical to those that the parents really bear (the genotype). When there are so many different options for coat colors in dogs, the only way to potentially detect or even get a sense of the true geneotype is to do test breeding. This is the only way.
The genes seem to follow the same patterns of dominance across all dog breeds, suggesting that all dogs share a fundamentally identical mode of color inheritance. So that we may discuss the colors of all canines using the same terminology. Letters are used to describe the genes that influence the color of the coat. These letters signify either the gene or the allele that is responsible for producing a certain hue. It has been shown that there are nine primary locuses (gene intersections) that influence the color of a dog’s coat, although it is not necessary for us to be concerned with all of them. The following are the fundamental genes that can be found throughout all nine canine loci:
The A locus, also known as the Agouti locus, is the most complicated gene, including at least five distinct alleles.
— A is the gene for a black coat that is predominant.
— the most prominent shade of yellow is ay.
— ag refers to the hue of an agouti or wolf.
— as well as a saddle pattern across the body, which consists of a broad saddle that is either black or liver brown and stretches over the shoulders, and tan markings on the head and legs.
— at is a black saddled dog with tan points, including tan eyebrows, cheeks, chest, and legs. — at is a saddled dog. In this particular instance, the saddle nearly completely envelops the torso.
B or Black denotes the possibility that a dog has black or dark pigmentation. There are just two alleles present, and in every circumstance, allele B is dominant over allele b.
b stands for chocolate, liver, or tan hues when there is a dark coat color. b also stands for the color black.
This gene, also known as C or Albino, determines whether or not a person will develop color based on certain patterns.
— The C gene is the dominant one, and it is responsible for the formation of color in the coat.
— cch gives the coat an appearance similar to that of a chinchilla.
CD is a canine companion with a white coat, a black nose, and dark eyes.
A dog with blue eyes has a cb coat, which is either white or very light gray in color.
— She has a pink nose and pink eyes, and she has an albino coat. The fact that the hairs are pink suggests that melanin cannot develop in them, which would allow them to display color.
D, also known as Dilution, has only two alleles once again.
— dominating D for strong pigment.
— recessive form D, which results in the pigment’s hue being more muted. The degree of dilution that takes place is directly proportional to the hue that is being altered by the solvent.
This gene is responsible for the extension or limitation of dark or black pigment in the coat, including the black mask, the brindle coat color, and other characteristics. E stands for “extension,” and it’s pronounced “extension.” A discussion of the operation of this specific locus is included later on in the page.
— the dominant allele is Em, which results in the formation of a black pigment in the coat that acts as a black mask.
— following that is E, which enables black pigment to be present in the coat without a mask; — following that is ebr, which is the brindle allele and enables black pigment to form stripes throughout the coat; — following that is e, which does not enable black pigment to be formed even if the dog carries the gene for black pigment; — following that is e, which prevents black pigment from being formed.
This does not indicate old age gray around the muzzle or premature aging in a dog; rather, it refers to the gradual natural lightening of the coat that occurs as a dog matures. G or Greying.
— G imparts an overall coat color that becomes lighter with age — g itself does not become lighter with age
S or Spotting is the term used to describe the white markings that may be seen on a dog, regardless of how extensive or few they are.
— S for self-colored or totally solid pigmented coat — st for Irish spotting, which shows a few definite areas of white (toes, chest, belly, muzzle or tail) — sp produces pinto or piebald spotting — sw is extreme white piebald coloring — — S for self-colored or totally solid pigmented coat — — S for self-colored or totally solid pigmented coat — — S for self-colored or totally solid pigmented coat —
This gene, known as T or Ticking, causes the white coat to have minute flecks of black hair throughout it. The ‘ticking’ that is most noticeable is that of the Dalmatian breed. In this breed, dominant T causes little colorful spots to appear in white sections of the coat, while recessive T causes the coat to have distinct white dots.
At least when it comes to pure bred Pugs, we don’t have to be too concerned about a lot of issues when we have pugs, which is a huge plus! It has been demonstrated through the use of specialized breeding techniques over the course of time that pure bred Pugs are homozygous, which means that both sets of genes inherited from the parents are identical, and that ALL PUGS carry the following set of genes:
B D Em g S t
Black Pugs carry either AA for pure black (AA BB CC DD EmEm gg SS tt) or Aay for the hybrid blacks (Aay BB Cc DD EmEm gg SS tt), and they contain at least one C gene. Pure black Pugs carry the AA gene set, whereas hybrid black Pugs have the Aay gene set. There is a strong possibility that the apricot fawns are carriers of the ayay allele of the C gene. The true silver color is ayay with probably the cch allele instead of the C (ayay BB cchcchDD EmEm gg SS tt), so it is easy to see how difficult it would be to have a true silver, as the cch gene is very difficult to find in Pugs at all, let alone to find two and mate them. Because of this, it is easy to see how difficult it would be to have a true silver. The presence of white spots in pugs (fawns also have white spots) is due to the dog carrying one of the S modifying genes, rather than the S gene itself. Fawns also have white spots.
Now that we’ve gotten that out of the way, let’s discuss the troublesome brindle color and how it just cannot exist in a pure bred Pug. First, the color of the animal’s coat is determined by the activity of the ayay gene, which might be red, tan, or fawn (in this case). The em has a dominating relationship with both the plain E and the plain e. That being the case, dogs who carry the EmEm, EmE, or Eme gene will always have the same appearance, which is fawn with a black mask. It is impossible to know for certain which gene a particular dog contains without having access to the breeding records of both the dog’s parents and their progeny.
Because the allele A for the black coat hides the brindle gene, dogs who have both the ebr brindle gene and the A allele for the black coat will have complete black coats. The brindle gene, ebr, when detected in conjunction with an Em will ALWAYS show up as a dog with brindle markings and a black mask. This is because the brindle gene is a recessive gene. Combinations of Eebr or ebrebr will result in brindle that does not have a black mask or brindle that is uniformly distributed throughout the body. However, if the ebr gene is present in ANY amount, even just one copy, the dog will ALWAYS have a coat that clearly displays the brindle pattern. Because of this, it is impossible to have a brindle gene that is recessive, and it is also impossible to have a brindle gene that is “hidden,” unless the dog is full black, which would hide the gene. However, the brindle colouring will appear in any dog that does not have a black coat and has the brindle gene. Therefore, if someone tells you that they married a fawn sire to a fawn mom and had a brindle puppy, you should know that this cannot occur genetically. If the mother is a fawn Pug, then the father had to have been another dog that DOES contain the brindle gene in order to produce this offspring. This was demonstrated during test breedings conducted in the 1940s under carefully monitored and controlled scientific conditions. Pugs have carried only the Em gene for over a century, which means that every dog has both the Em and the EmEm genes. Therefore, all dogs in existence today who contain the brindle gene must have originated from another breed that had the ebr gene, making them a hybrid breed of dog.