Cat coat genetics

Cat coat genetics governs the coloration, pattern, length, and texture of feline fur. Understanding these genetics can help explain the wide variety of coats seen in domestic cats and is also useful in breeding for desired traits.

Overview

The genetics of cat coats are determined by multiple genes that influence color, pattern, and hair length. The primary genes include those for coat color (B locus, C locus, D locus, O locus, and S locus), coat patterns (Tabby gene, Spotting gene, and Ticked gene), and hair length and texture (Longhair gene and Rex gene).

Color Genes

The color of a cat's coat is primarily determined by two pigments: eumelanin (black or brown) and pheomelanin (red or yellow). The presence and intensity of these pigments are controlled by various genes:

• B locus: Determines the intensity of the black or brown color.
• C locus: Affects the overall color saturation and can lead to albinism in its recessive form.
• D locus: Controls the dilution of the color, leading to lighter shades.
• O locus: Determines whether a cat will display orange/red colors and operates on the X chromosome, leading to tortoiseshell or calico patterns in females.
• S locus: Influences the presence and distribution of white spotting.

Pattern Genes

Patterns in a cat's coat, such as stripes, spots, or ticking, are influenced by several genes:

• Tabby gene: Responsible for the classic, mackerel, spotted, and ticked tabby patterns.
• Spotting gene: Determines the size and distribution of spots, as well as solid versus bicolor coats.
• Ticked gene: Causes the individual hairs to have bands of color, seen in breeds like the Abyssinian.

Hair Length and Texture

The length and texture of a cat's coat are also genetically determined:

• Longhair gene: A recessive gene that results in long fur.
• Rex gene: Leads to curly or wavy fur, seen in breeds like the Devon Rex and Cornish Rex.

Genetic Inheritance

Cat coat genetics follow Mendelian inheritance patterns, with alleles being dominant, recessive, or co-dominant. For example, the longhair gene is recessive, so a cat must inherit two copies (one from each parent) to have long fur. Similarly, the O locus is sex-linked, which explains why calico and tortoiseshell patterns are almost exclusively found in females.

Breeding and Predictability

Breeders can use knowledge of cat coat genetics to predict the appearance of offspring. However, due to the complex interaction of genes, predicting coat colors and patterns can sometimes be challenging.

Health Implications

Some coat colors and patterns are associated with health conditions. For example, white cats with blue eyes are more likely to be deaf. Additionally, certain genetic mutations that affect coat color or texture can also lead to health issues.