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# MFSD12 gene
- URL: https://equinecolors.com/mfsd12-gene/
- Published: 2026-02-23T11:43:12.000Z
- Updated: 2026-07-30T20:10:57.000Z
- Description: The MFSD12 gene is responsible for the color mushroom in horses.
- Author: Hannelore Roodhooft
- Tags: Genetics, Dilutions, #Import 2026-08-12 09:42

The MFSD12 [gene](https://equinecolors.com/dictionary/#:~:text=in%20each%20pair.-,Gene,-A%20gene%20is) is responsible for the mushroom coat color in horses.

## Alleles

There are two currently known [alleles](https://equinecolors.com/dictionary/#:~:text=the%20DNA%20sequence-,Alleles,-Different%20versions%20of).

The [recessive](https://equinecolors.com/dictionary/#:~:text=Recessive%20Allele%20%28written%20in%20lowercase%20letters%29) **mu-allele** (mushroom) dilutes the coat of chestnut and bay-based horses to a sepia-toned color.

The wild-type **n-allele** leads to the production of normal amounts of pigment.

| **MFSD12** | **Color**                       |
| ---------- | ------------------------------- |
| **mu/mu**  | Chestnut mushroom, bay mushroom |
| **mu/n**   | No dilution                     |
| **n/n**    | No dilution                     |

## Mechanism

Pigment cells, called **melanocytes**, produce the pigments in the hair and skin of horses. The production of pigments can be influenced at different stages, changing the **type (black or red)** or the **amount (dilutions/ white patterns)** of pigment that is made.

![CTA Image](https://equinecolors.com/content/images/2025/12/Equinecolors_Icon_DNA1-29.png) 

The production of black and red pigment involves several different steps. Some of these steps are shared between the two, and some are unique to each pigment type. This is why certain genes will affect all base colors, while others only affect either red or black pigment: they affect different steps. 

### MFSD12

The MFSD12 gene codes for the **MFSD12 protein** (Major Facilitator Superfamily Domain Containing 12), and has been shown to play a role in the amount of red or black pigment that is produced. It **suppresses** the production of **black pigment**, while it is **required** for the production of **red pigment**.

It is thought that the mushroom mutation leads to a non-functional MFSD12 protein and less red pigment as a result. At the same time, it increases the production of black pigment, which could explain the darker [countershading](https://equinecolors.com/dictionary/#:~:text=Horse%20Terms-,Countershading,-Darker%20color%20on) on bay mushroom horses.

Antes de elegir entre [camisetas de fútbol en línea](https://www.camisetatienda.com/?ref=equinecolors.com), merece la pena comprobar la comodidad, el tejido y la frecuencia de uso. También ayuda revisar que la descripción coincida con las fotografías y las opciones seleccionadas antes de completar el pedido.

| **Alleles** | **Mutation**        | **Effect**          |
| ----------- | ------------------- | ------------------- |
| mu          | Frameshift mutation | Red pigment diluted |
| n           | /                   | No dilution         |

## Colors

[MushroomMushroom is a coat color modifier that lightens the coat of chestnut and bay-based horses to a distinctive “sepia” toned coat .![](https://equinecolors.com/content/images/icon/favicon-170.ico)Equine ColorsHannelore Roodhooft![](https://equinecolors.com/content/images/thumbnail/mushroom.png.png)](https://equinecolors.com/mushroom/)

**Read more:**  
[Color genes](https://equinecolors.com/color-genes/) | [MATP gene](https://equinecolors.com/matp-gene/) | [TBX3 gene](https://equinecolors.com/tbx3-gene/) | [PMEL17 gene](https://equinecolors.com/pmel17-gene/)

[Back to Dilutions](https://equinecolors.com/dilutions/)

## Articles

1. Tanaka, J., Leeb, T., Rushton, J., Famula, T.R., Mack, M., Jagannathan, V., Flury, C., Bachmann, I., Eberth, J., McDonnell, S.M., Penedo, M.C.T., Bellone, R.R.; **Frameshift Variant in MFSD12 Explains the Mushroom Coat Color Dilution in Shetland Ponies**; Genes *(*2019); Doi: [10.3390/genes10100826](http://dx.doi.org/10.3390/genes10100826?ref=equinecolors.com)