Edited by Ruoqi Lin.
January 20, 2025

Genetics and History of the Shaded Maine Coon Cats

This striking breed originated in Maine coon and has some cool genetic quirks. Breeders have selected for different mutations and genes over time, creating the unique shaded color variant that many cat enthusiasts love.

Shaded Maine Coons are known for their distinct fur color and elegant looks. They have a light gray coat with black noses, dark eye linings, and black paw pads. Their unique coloration is due to a combination of the inhibitor gene, the wide band gene, and a modifier gene. TICA's description for them: “Shaded and Chinchilla Silvers are essentially tabby cats with a depigmented (white), wide agouti band. The hair on the shaded and chinchilla silvers are “tipped” with eumelanin-based or phaeomelanin-based color. The shaded has color from the tip to about one-third way down the hair shaft. The appearance is one of having a mantle of color thrown over the back. The chinchilla will have only the tip of each guard hair colored. Shaded and chinchilla silvers may be born with visible tabby pattern. As they mature, the wide band area increases and the cat appears to be primarily white, tipped with color. The shaded and chinchilla patterns are traditionally distinguished only by the degree of tipping, the shaded being the more heavily tipped cat. ”

While some may argue that this coloration should be classified as "extreme silver" rather than traditional "shaded," primarily due to its lighter appearance, this discussion seeks to delve into the genetics, historical context, and common inquiries surrounding Shaded Maine Coons.

Based on comprehensive observations of shaded phenotypes in Persian cats and other breeds, as well as thorough reviews of the descriptions of Shaded and Chinchilla by TICA and CFA, it is evident that the shaded phenotype encompasses a broader range than traditionally defined. Each shaded cat exhibits a slightly different expression of the phenotype.

Historical records of shaded cats are limited, leading to varied interpretations and controversies. This article invites readers to set aside preconceived classifications and biases and approach this topic with an open and analytical mindset, to fully appreciate the nuances and characteristics of Shaded Maine Coons.

In this discourse, we will explore the intricate genetics, shed light on the historical evolution, and address prevalent questions surrounding shaded cats. The coloration in question, often misidentified as "extreme silver," firmly belongs within the shaded category and merits recognition and appreciation as such.

Shaded Maine Coon (Classic Tabby)

british-silver-shaded-male-kitten-260nw-

Shaded British Shorthair (Mackerel Tabby)

Shaded Persian Doll Face

(Unknown Tabby)

The origins of the Shaded Maine Coon have been a subject of much debate. While this color variant has become increasingly popular, its exact beginnings remain uncertain. A widely accepted theory suggests that in 1977, a breeder introduced Burmilla genes into the Maine Coon gene pool, leading to the creation of Cork Felix, a foundation cat for the ticked tabby lines. Additionally, a significant genetic event in the Maine Coon lineage occurred with a cat named Belushies Utha about 99.99% in all shaded lines. This combination gave rise to the unique shaded phenotype we see today.

Belushies Utha

Cream Silver Classic Tabby

However, Shaded Maine Coons have appeared multiple times between the 1970s and 2010s. These earlier cats didn’t meet the current association standards for shaded color, which demands lighter fur. Early shaded cats had darker coats, falling short of the modern shaded standard.

The first "truly modern" Shaded Maine Coon was recognized around 2014, at Alwaro Cattery. This updated definition of shaded color does not invalidate previous cats; instead, it's a result of advances in breeding techniques and gene expression, evolving into the familiar appearance we know today. Following this, various bloodlines began to exhibit the shaded trait, demonstrating its presence within the Maine Coon population rather than from later crossbreeding. Both American and European lines contain shaded Maine Coons, though the trait is more common in European lines due to breeders’ preference for lighter-colored cats. However, shaded Maine Coons are also found in American lines, suggesting that this color trait was already present in the Maine Coon gene pool since the 1974-2014s, not the result of hidden crossbreeding.

Does Shaded Affect the Body Shape and Fur of Cats?

Regarding the question of whether shaded Maine Coon cats have a smaller body size, the answer is no.

The shaded gene does not affect the size of Maine Coons. This color trait emerged from the incorporation of external bloodlines in the 1970s and has been maintained for over 50 years and more than 40 generations. The Maine Coon lineage is composed of numerous cats, and no single cat's traits can determine the overall size of the breed.Historically, our cattery's largest two intact Maine Coons are both shaded. One was a black shaded male named Alwaro Lord Dallas, weighing 9.5 kg (approximately 21 lbs), but unfortunately, he passed away before the age of two due to urinary disease. The other is a red shaded male named Vorkun Snowball, weighing 10.2kg (approximately 22.5 lbs), making him the heaviest cat in our records. This clearly shows that shaded Maine Coons do not exhibit any size limitation due to their color.

As for the texture of their fur, shaded Maine Coons mostly come from European lines, which might result in them having fluffier and more cotton-like fur rather than a silky texture. However, this is not absolute, as there are also shaded Maine Coons with silky fur. Similarly, Maine Coons from other bloodlines can also have cotton-like fur. Therefore, the differences in fur texture are more influenced by their bloodlines rather than the shaded color itself.

Vorkun Snowball at 7 Months old

Are Shaded Maine Coons Carriers of Genetic Diseases?

The question of whether shaded Maine Coon cats carry any lethal genetic diseases is a critical concern for many, and it is also a topic of utmost importance to us. It is essential to note that the shaded coloration itself does not inherently carry any specific lethal hereditary diseases. This phenotype results solely from the expression of coat color genes and does not directly impact the health of the cat. However, it is true that health issues are statistically more prevalent within shaded bloodlines compared to other color variants. This observation is primarily attributed to the practice of inbreeding that occurred during the early popularization of the shaded trait.

In the initial years when shaded Maine Coons first gained popularity, breeders often resorted to excessive inbreeding to stabilize this desirable trait. Consequently, this led to a higher inbreeding coefficient within certain bloodlines, thereby increasing the risk of hereditary diseases.

To address and mitigate these health concerns, we have implemented rigorous health screening protocols for our shaded breeding cats. Before any shaded cat is incorporated into our breeding program, it undergoes comprehensive genetic testing to confirm that it does not carry any known high-risk genetic diseases. Additionally, the majority of our shaded breeding cats come from trusted colleagues or long-term partner catteries. Through these exchanges, we establish cooperative relationships and ensure genetic diversity within our breeding lines. We seldom introduce shaded breeding cats from unfamiliar catteries to safeguard the health of our lines. This practice significantly reduces the risk of inbreeding and contributes to the stability and reliability of our shaded bloodlines.

We consistently prioritize health as our foremost concern.

The Impact of Tabby Patterns on Shaded, and Silver Tabby

Shaded is actually a pattern rather than a color. This means each shaded cat will exhibit some form of tabby markings, be it classic tabby, ticked tabby, mackerel tabby, or spotted tabby. These various patterns create distinct effects under a shaded coat.

Among them, ticked tabby stands out for its uniformity. Because ticked tabby lacks overt pattern separation, shaded cats with this pattern appear exceptionally smooth, with almost every hair sharing similar band frequencies, devoid of light and dark "patches”—a phenomenon known as the "merle effect." It is important to clarify that the "merle effect" is not a color or a pattern. Rather, it's a presentation style with a genetic predisposition, but it isn't controlled by a single gene and can't be entirely predicted. It differs from the merle effect seen in Border Collies and cannot be registered as a color.

In contrast, classic tabby and mackerel tabby patterns, due to their stripe distributions, often result in shaded cats having alternating dark and light patches, giving a more chaotic visual texture. Each hair strand varies, with one having a short dark banded tip, the next with two dark bands, another with a medium dark tip, and so forth. A thorough examination reveals some hairs to be solid black or white, while others present a seemingly erratic mix, making the hair follicles appear inconsistent in their coordination. A well-bred classic tabby maintains even coloration, with minimal "confusion or Merle"

Within the black striped regions of a classic tabby without Shaded, the hair reveals a banded pattern where the tip is true black pigment, and the undercoat bears brown bands. In silver tabbies, this banded pattern changes; the pigment tip is shorter, band frequency higher, and the undercoat closer to a gradient silver-white. As the coloring extends to the belly, it typically becomes lighter, sometimes appearing pure white, lacking root pigmentation.

Black Silver Shaded with White（Ticked Tabby)

Black Silver Shaded（Classic Tabby)

Black Silver Tabby（Classic Tabby)

How is the Shaded Color Inherited in Maine Coon Cats?

The shaded phenotype in Maine Coon cats is neither a dominant gene nor a recessive one. This means that the phenotype is due to the combination of three genes: the inhibitor gene, the wide band gene, and a modifier gene. The modifier gene influences the phenotypic expression and/or molecular expression of other genes and can affect the band frequency of the fur. When both parents carry the shaded trait, the likelihood of producing shaded offspring is higher. Chinchilla pairings have the highest probability of producing shaded progeny.

Working with shaded genetics over these years has provided some fascinating insights into the probabilities of producing shaded or chinchilla offspring. Here’s a detailed breakdown:

Probability of Producing Shaded or Chinchilla Offspring:

Chinchilla x Chinchilla: Highest probability of shaded or chinchilla offspring.
Shaded x Shaded: Slightly lower but still high probability.
Chinchilla x Carrier of Shaded Gene: Next highest probability.
Shaded x Carrier of Shaded Gene: Slightly lower probability than Chinchilla x Carrier.
Two Carriers of Shaded Gene: Lower probability.
Non-Carrier x Carrier: Very low probability.
Non-Carrier x Non-Carrier: Impossible to produce shaded offspring.

The shaded genotype is one of the most complex color patterns in cat genetics. The shaded phenotype involves multiple distinct genes. When shaded cats are bred with non-carriers and carriers of the shaded gene in classic tabbies, their offspring exhibit genetic independence. It is the combination of these genes that results in the shaded color.

It is not recommended to continuously pair chinchilla with chinchilla or shaded with shaded cats. While it increases the probability of producing shaded or chinchilla kittens, it also risks mixing too many shaded bloodlines. Given the limited number of shaded Maine Coons, such practices may lead to a high inbreeding coefficient, eventually impacting the overall health and genetic diversity of shaded Maine Coons.

The ideal pairing strategy involves mating shaded cats with either carriers of the gene or with non-shaded cats. Such pairings produce carrier kittens that can be subsequently mated with shaded cats. This method ensures the quality of shaded kittens while maximizing genetic diversity, improving overall health, and effectively reducing inbreeding rates.

It is important to note that when shaded cats are mated with any other color, their offspring will always carry the shaded gene. This means that even if the kittens do not externally present as shaded, they can still transmit this recessive gene to the next generation through further breeding. An informed pairing strategy not only preserves the distinctive shaded phenotype but also ensures the long-term health and genetic stability of Shaded Maine Coons.

This article is written based on my research and personal insights regarding the extreme silver & shaded phenotypes. If you have any questions or concerns, please feel free to contact me. I am more than happy to discuss or correct any inaccuracies.

References:

INHIBITOR GENE: SILVER AND GOLD: SMOKE, SHADED AND TIPPED CATS

Part 10 - Wideband - Description - Silver/Golden-Shaded/Shell

Emailing-UCD-Version-B-30-May-2022-4.pdf

The Genetics of Shaded Silver American Shorthairs

Basic Feline Genetics - cfa