Recessive Genes in Cat Breeding: PART ONE: What Is a Recessive Gene?

Featuring the Dilute Gene — the “Soft Colour” Secret in Cats

Examples of the dilute gene, top left is a seal Burmese and to the right is its dilute, a blue Burmese and bottom is a lilac Burmese, a dilute of chocolate.

When we admire a gorgeous blue, lilac, cream, or fawn cat, we’re really admiring genetics at work. Behind every coat colour lies a tiny set of instructions written in DNA — and some of those instructions are quiet, subtle, and easily overlooked. These are recessive genes.

Understanding them is the key to predicting colour outcomes, avoiding surprises in the kitten room, and protecting valuable genetic diversity in your breeding lines.

Let’s dive in.

Dominant vs Recessive: Who Speaks Loudest?

Every cat carries two copies of each gene — one from its mother and one from its father.

• A dominant gene only needs one copy to be seen in the cat’s appearance.

• A recessive gene needs both copies to match before it shows itself.

Think of dominant genes as speaking loudly:

“I’m here — and I’m in charge!”

Recessive genes whisper:

“I’ll wait quietly… unless there are two of me.”

So a cat can carry a recessive gene without showing it. These hidden carriers are incredibly important in breeding.

The Dilute Gene

The dilute gene affects how strongly pigment is produced in the coat. It doesn’t change the base colour family — instead, it softens it.

• Black becomes Blue

• Chocolate becomes Lilac

• Cinnamon becomes Fawn

• Red becomes Cream

This is Glitterpaws Cocosplash Penelope, a chocolate Burmese with her litter of 8, she was mated to Bahati Georgio Armani - an ebony Mandalay. Two recessive genes are at play here as Burmese (pointed) is recessive to Mandalay (solid colour) as well as the dilute gene. This litter produced and ebony (solid black) and its pointed- a seal, a blue (dilute of seal), 3 chocolates and 1 lilac (the dilute of chocolate), and a lavender (solid of lilac), -a truly rainbow litter!

The Genetics

• Dominant allele: D (full colour)

• Recessive allele: d (dilute)

Genotypes and Phenotypes

Genotype is the genetic code an animal carries, while phenotype (or "photo") is how those genes are actually expressed in its physical appearance or traits.

Genotype	What It Means	Coat Appearance
DD	Non-dilute, not a carrier	Full colour
Dd	Carrier of dilute	Full colour (but carries dilute)
dd	Dilute	Dilute coat colour

Only dd cats will appear dilute.

Carriers: The Hidden Players

A cat with Dd looks full colour — but secretly holds the dilute gene. Carriers are crucial because they:

• Keep recessive traits alive in the breed

• Can produce dilute kittens when matched correctly

• Add diversity without changing phenotype

Recessive genes can hide for generations, then pop up when the right pairing occurs.

How Is Dilute Inherited?

Both parents must contribute one d allele for a kitten to be dilute.

This means:

• Two dilute parents (dd × dd) = all dilute kittens

• One dilute parent (dd) and one carrier (Dd) = 50% dilute, 50% carriers

• Two carriers (Dd × Dd) = 25% dilute, 50% carriers, 25% full colour non-carriers

Punnett Square Example

Let’s imagine a mating between two carriers of dilute (Dd × Dd). Neither parent looks dilute — but both carry the recessive allele.

Carrier × Carrier

           D        d
        ----------------
     D |    DD     Dd
        |
     d |    Dd     dd

Outcomes:

• 25% DD – Full colour, not a carrier

• 50% Dd – Full colour, but carriers

• 25% dd – Dilute kittens

So even if both parents look full colour, a dilute kitten can still arrive — like a genetic surprise party.

Why This Matters in Breeding

Understanding recessive inheritance helps breeders:

• Predict litter outcomes

• Make informed pairing decisions

• Maintain colour diversity responsibly

• Avoid accidental loss of valuable recessive traits

Carriers are incredibly important — they’re the hidden genetic custodians of recessive colours like lilac, blue, and cream.

Key Takeaways

• A recessive gene needs two copies to be seen.

• Dilute cats are always dd.

• Full-colour cats can still carry dilute.

• Carrier × carrier matings can produce dilute kittens.

Final Thought

Recessive genes may be quiet, but they shape some of the most beautiful colours in our pedigrees. By understanding how they work, we can plan breedings wisely — protecting both type and genetic diversity.

Glitterpaws science is my favourite kind!