L locus — coat length

Controls: Whether the coat is short or long.

How it works

The L locus controls hair length. Dominant L gives a short coat; two copies of the recessive l give a long coat. This is why two short-haired cats can produce long-haired kittens.

Alleles

LShortDominant

lLongRecessive

Breeding examples

Shorthair carrying long (L/l) × Shorthair carrying long (L/l)

← ≈ 3 in 4 short-haired, 1 in 4 long-haired.

Longhair (l/l) × Longhair (l/l)

← All kittens long-haired.

Frequently asked questions

Can two short-haired cats have long-haired kittens?+

Yes — if both carry the recessive long-hair allele, a kitten can inherit two copies and be long-haired.

Does coat length change the colour genetics?+

No — length is independent of colour and pattern. The same colour genes give the same colours whether the coat is short or long.

Related genes

W locus — dominant white

A fully white coat that masks all other colour.

B locus — black series

Whether the black pigment shows as black, chocolate or cinnamon.

D locus — dilution

Whether a colour is dense (full) or dilute (softened).

See these colours on real cats.

Browse cat colours