Ivaloueva / Getty Images It's a fact that 99.9 percent of all calico cats are female because of the unique chromosomal makeup that determines the color variations in their coats. Each cat has a pair of sex chromosomes with the possible combinations of XX (female) and By (male).
The X chromosome also carries the coding gene for the black and orange colors in a calico's coat. During development, one X chromosome will override the other, allowing either black or orange to be the dominant color.
This particular color development occurs in each individual cell, shutting down one X chromosome while allowing the other to be active. To make things even more complicated, calico cats must also inherit a gene unrelated to the X and Y chromosomes that codes for white fur.
There is one exception to the females- only calico rule: A genetic anomaly called Klinefelter’s Syndrome. In humans, Klinefelter’s Syndrome occurs when a male inherits an extra X chromosome from either his father or mother, making his genetic makeup OXY.
Unfortunately, since male calico cats are born because of a genetic anomaly, they are often much less healthy than their female counterparts. Male calicoes often have reduced bone mineral content, increasing the risk for broken bones; cognitive and mental developmental issues, which can lead to behavioral problems; and increased body fat, which can cause joint pain, heart disease, and diabetes.
This is also true for a similar coat pattern called tortoiseshell. Genetics behind calico coat pattern Calico, or tricolor coat pattern, is the pattern of white fur with patches of two different colors, most commonly orange and black (or their diluted forms: cream, ginger, red and blue, tabby, gray).
There is usually a significant amount of white in their coat, and the red and black patches form patchwork. A similar coat pattern is tortoiseshell, where there is a lot less white in the fur, and the colored patches are mottled.
The gene which determines whether the coat will be orange or black (or one of the diluted colors) lie on the X chromosome. If a female cat is a heterozygote for the orange gene (OO), it will carry the orange allele (O) on one X chromosome and the non-orange allele (o) on the other X chromosome.
The cells in which the first X chromosome is silenced will express only the non-orange gene, and therefore produce the black (or brown) pigment, and the other cells will produce the orange pigment. The third color of a calico is a product of a completely separate gene.
This is a chromosomal mutation known as XX male syndrome. This mutation exists in humans too, and it's called Klinefelter syndrome.
Ordinarily, male cats have By sex chromosomes, while females have XX. Therefore, female cats inherit their coat color from both their queens (XX) and their toms (By).
Geneticists have discovered that only one of the two X chromosomes in females is functional, which explains why you usually can make a blanket prediction that any male offspring will be the color of the queen. Note that the presence of the extra X chromosome doesn’t in itself create the calico.
Understanding why nearly all calico cats are female takes us back to high school biology class. Think back to Punnet squares and you'll remember that babies receive one chromosome each from their mother and father.
This rule applies to humans, dogs, horses, cats, and all our other furry friends. So instead of the cat's fur coming out all orange or all black, it has patches of each color.
Those cells replicate, and the cat ends up with patches of both black and orange fur. This special coat color phenomena can happen in any and all different cat breeds.
A male calico must receive an extra X chromosome from either his mother or his father, making his genetic makeup OXY. In humans, this condition is called Klinefelter's Syndrome, and an OXY cat is almost always sterile.
The calico is thought to be good luck in many cultures, and are sometimes referred to as money cats. “Mani Nero, a Japanese cat talisman thought to bring good fortune and wealth, is almost always calico.
The Baltimore, Maryland Orioles baseball team also wears these colors. When I adopted a calico kitten, Rookie, several years ago, I didn’t think twice about the fact that she’s female.
I wanted to get a female cat, and Rookie was adorable and fit with my personality, so that was that. To start this investigation, it’s important to point out that calico is a color pattern of a cat, not a breed.
This eliminates a breed specific reason for a female majority of calicoes. In fact, any breed of cat can be born with calico fur; although, it’s rarer for purebreds like say, Russian Blues.
In order for a cat to be considered calico,” three colors must be present in the coat: white, black, and orange. Since a male cat only has one X-chromosome from his mother, his fur color is dictated by that gene.
When a female cat is in fetal development, one of her two X-chromosomes is randomly deactivated, which is known as X-inactivation, for each cell. White fur is determined with a separate gene and may speckle throughout the coat.
A male cat can have tricolor fur if he inherits an extra X-chromosome, making his genetic makeup OXY as opposed to By. If you spot a male calico, it’s highly likely that this cat is sterile, or unable to reproduce.
Breeders still tend to shy away from these fertile male calicoes, as there are potential health issues that can arise in their offspring due to the extra chromosome. While any breed of cat can be born with calico fur, the vast majority of these cats are female, with only about one in three thousand calico cats born male according to the Humane Society.
Because in cats the X-chromosome determines most of the fur color (with the potential exception of white). A male offspring only receives an X-chromosome from his mother, so that alone determines his fur color.
Each cell only needs one X-chromosome, so early on when the feline embryo is developing, one of the two gets shut off, with the inactivated one super coiling into something called a “Barr Body.” In both cases, these cells are replicated and the inactivated chromosome will always stay inactive.
A male cat can have tricolor fur if he inherits an extra X-chromosome, making his genetic makeup OXY. In humans, as with cats, the individual in question is usually considered genetically male despite having two X chromosomes.
Besides potential other health issues, the extra X-chromosome almost always causes male calico or tortoiseshell cats to be sterile. For this reason, and potential other health problems with the cat, even when these rare fertile male calico or tortoiseshell cats do pop up, they are almost never used for breeders as there are simply no advantages, and some disadvantages, to using them over more virile felines.
It was once popularly thought that cats were domesticated by humans in order to provide rodent control. A cat’s normal body temperature is around 101.5° F. Unlike humans, they can comfortably withstand high external temperatures ranging up to 126° F to 133° F before showing any signs that they are hot.
Their feces are also typically very dry and their urine highly concentrated so as not to waste water. They accomplish this largely via a tape tum lucid um, which reflects light passed through the retina back into the eye.
They also have exceptionally large pupils for their body size and a much higher density of rods than humans do. For reference, humans hearing range is typically between 31 Hz to 18 kHz and dog’s hearing range is typically between 67 Hz and 44 kHz.
Actually, calico isn’t a breed of cat but a type of coat coloring. In this post you’ll learn all about calico cats, what makes them so special, and why it’s rare to find a male calico cat.
Apart from the term used to describe a type of cat coat coloring, calico is also a fabric. Made from unbleached cotton, calico is slightly thicker than muslin.
If you’re interested in knowing what makes a cat develop calico coloring, it’s all down to genetics. To prevent a potentially dangerous double dose of survival proteins, one of the X chromosomes is switched off.
This is known as X chromosome inactivation and occurs in the womb when the kitten is just a tiny ball of cells. To try and simplify things, if an X chromosome carrying The white coat color gene is switched off in an area of the cat’s body, black or orange fur will grow there instead.
If one of your kitten inherits two Lb alleles from both parents her fur will be black. As you can imagine this will result in patches of orange and black similar to tortoiseshell.
Unlike tortoiseshell cats, calicoes have white patches of fur, as well as black and orange. If you’re not familiar with this term, it simply means white spotting gene.
Cows, rabbits, guinea pigs, and horses are examples of other animals that carry the piebald gene In contrast, tortoiseshell cats have coats with a mix of orange, black, and white forming a brindled pattern.
Just to complicate things, there are variations that can make it hard to tell if your cat is a sortie, or calico. Calico cats can be found in a variety of breeds, from Persian to British Short hair.
Breeds that do allow calico though include Persian, British short hair and Manx. If you manage to find a male calico kitten, just because it’s sterile doesn’t mean there’s no need for neutering.
That being said, there are many owners who say how sweet and loving their calico kitties are:) It’s also been claimed they’re very loyal with a brave trait. The belief was they’d protect their ship from harm and ensure a safe passage.
In the USA male calico cats are referred to as “money cats.” This is because many mistakenly believe they’re of high value. You’ll find a Nero cat figurine with a beckoning paw outside many Chinese restaurants, and in homes.
The cat is depicted as a calico with mostly white coloring and splodges of black and orange. The lower paw carries an item such as a magic money mallet, marble, gem, or a Japanese coin.
Lastly, an old Irish folklore suggests that if you have a wart, rubbing it against a calico cat’s tail will get rid of it! This is the state bird, and you’ll also find orange, black and white worn by the Maryland Orioles basket ball team.
There are plenty of resources online to help, and contacting local breeders is another option. In this article you’ve discovered exactly what calico cats are and how genetics plays a big part.
They’re generally easier to care for than dogs and make ideal pets if you live in an apartment. That said, exceptions to this rule can occur with atypical genetics due to mutations or chimeras, resulting in the elusive male calico cat.
The calico coat involves a combination of orange, black and white patches. Cats receiving two sets of X chromosomes (XX karyotype) are female and cats receiving one set of each X and Y chromosomes (By karyotype) are male.
The tricky part is that the orange coat color alleles are only found on the X chromosome, making this a sex-linked trait. Whereas a recessive allele (o) is non-orange, allowing the black coat color to be present.
Contrary to popular belief, all orange cats are not male and are just as likely to be female. In order to achieve the full calico appearance, cats that are tortoiseshell with the heterozygous orange gene (OO) must also develop white patches.
Male cats have calico or tortoiseshell coats if they have an extra X chromosome or are a chimera. Chimeras occur when two embryos are fused together during development, resulting in the combination of genetic material, yet this is very rare.
For example, the tabby cat has a variety of different alleles that can result in different striped, patchy or ticked patterns. Cats may have an about gene, which can result in variations in the color on a single strand of hair.
Genetics also play a role in the specific shade of a coat color by affecting the distribution of melanin (pigment) within the hair. There’s a reason that colorful cats, like tortoiseshells and calicoes, tend to be female.
If a female cat inherits one X chromosome with the black allele and one with the orange version, each cell will have both versions, but X-inactivation means that some of her skin cells will code for orange and some for black. One of those primordial skin progenitor cells that happens to have an active orange allele will give rise to a cohesive blob of millions of cells in the fully developed cat, forming a big orange blotch.
Even with the exact same genetic make-up, a calico cat’s coloration would be different from her twin’s because it’s random whether a cell codes for orange or black fur. Because X-inactivation only happens if there are multiple X chromosomes in one cell, coloration patterns that stem from the process tend to only pop up in female cats.
Rarely, a genetic mutation can result in a cat being born with an extra chromosome (OXY), leading to a male calico or tortoiseshell cat, but for the most part, it’s purely a ladies’ club.