The genes that build it
Every feather in a mille fleur bird tells the same little story from base to tip — gold, then black, then white — and each part comes from a specific gene. The full genotype is eb/eb · Db/Db · Pg/Pg · Ml/Ml · mo/mo:
| Gene | Genotype | What it contributes |
|---|---|---|
| Extension — brown | eb/eb | The gold / red-brown ground colour (pheomelanin). |
| Dark Brown | Db/Db | Deepens the ground to a rich mahogany-gold. |
| Pattern & Melanotic | Pg/Pg, Ml/Ml | Organise eumelanin into a black spangle at the end of each feather. |
| Mottling | mo/mo | The recessive mottling gene tips each feather white — the "flower" spot.1 |
So the tricolour is built in layers: a gold-brown base (eb) enriched by Dark Brown (Db); a black spangle laid onto each feather by the Pattern and Melanotic genes (Pg, Ml); and a white tip added by Mottling (mo). The mottling gene is the pattern's signature — it is recessive, and the same gene on different bases also produces mottled, speckled and related looks.1 Add a single copy of the Blue gene (Bl/bl+) and the black spangles dilute to blue — the "blue mille fleur" variant.
How it breeds
Because the defining gene is recessive, two things follow for anyone working with mille fleur:
- Mille fleur × mille fleur breeds reasonably true for the mottling — both parents are
mo/mo, so all chicks are too (the ground-colour modifiers can still vary). - Crossing mille fleur out to a non-mottled bird loses the white tips in the F1 — those chicks are mottling carriers that look un-mottled — and the white tips reappear in about a quarter of the F2, the classic recessive pattern.
Db, Pg, Ml and the recessive mo all to two copies on a brown base — recreating mille fleur from parts is a multi-generation project. It helps that Db, Pg and Ml are linked genes that tend to travel together once you have them. The Breeding Outcomes tool is built for exactly this kind of multi-locus planning.
Related patterns
- Porcelain is mille fleur with the lavender gene added, which softens all its colours — see Porcelain genetics.
- Tollbunt swaps the Dark Brown gene for Columbian, which pushes the black to the feather edge for a laced look instead of a spangle — see Tollbunt genetics.
- Mottled is the same mottling gene without the gold ground and black spangling of mille fleur — most familiar on a solid black base (the Ancona: black feather, white tip), but
mo/moworks on many bases, so mottled and speckled varieties also appear on red, buff and other grounds. See Mottling genetics. - The white-tipping behaviour of
mo/mois defined in the glossary alongside the other pattern terms.
- Somes RG Jr (1980) The mottling gene, the basis of six plumage color patterns in the domestic fowl. Poultry Science 59(7):1370–1374 — establishes the recessive mottling gene (
mo) as the shared basis of mottled, mille fleur, porcelain and related spangled patterns. - Extension (E-locus) base and the
ebbrown/partridge allele: Smyth JR Jr (1990) Genetics of plumage, skin and eye pigmentation in chickens, in Crawford RD (ed.) Poultry Breeding and Genetics, Elsevier. See the Genetics Guide references.