Tricolor cats are one of the most popular pets that are famous for their unusual color. An unusual phenomenon of this breed is the absence of a tricolor coat color in male cats. What is it connected with?
The origin of tricolor cats
Tricolor cats have a pronounced color in the form of spots of black, red and white. The black tint appears due to the eumelanin pigment, while the red tint is completely dependent on the pheomelanin pigment. Their color can be modified by certain genes that turn them into red and chocolate, blue and cream, as well as cream and purple shades.
The name of the tricolor cats Calico cat comes from a type of cotton fabric that was invented in India.
In Japan, this breed is called mike-neko, literally meaning "three-colored cat". In Dutch translation lapjeskat means "patchwork cat". The term "tricolor" in this case means only the color of the coat and has nothing to do with the breed itself. Cat breeds that can be tricolored include American and British Shorthair cats, Maine Coons, Manxes, Japanese Bobtails, Persian cats, Exotic cats and Turkish Vans. The main color in tricolor cats is white, while on colored spots they may have a tabby pattern.
Why cats are not tricolor
The absence of a tricolor color in cats of this breed is explained by the X chromosome, which determines the color of the coat. Unlike females with two X chromosomes, males have one X and one Y chromosome, therefore, the simultaneous combination of black and orange pigments is practically not found. The only exception is the presence of a set of sex chromosomes XXY, in which cats have a tricolor or tortoiseshell color.
Most often, tricolor cats are completely sterile, since the presence of two X chromosomes is an abnormality that causes infertility.
The orange gene, which affects the color of the coat and is tied to the sex, is found only in Syrian hamsters in cats. All melanocytes derived from a cell with its active allele "o" stain the coat red, regardless of the genotype. Melanocytes with an active "o" allele are black. If they have the agouti gene in them, the coat will be covered with islets of black or red pigment. Today this gene is very poorly studied, but it is known that it is he who neutralizes the effect of the mutant allele, which evenly stains the coat with melanin of the same type. As a result, spots or stripes appear on a red background in tricolor cats, regardless of the genotype for the agouti gene.