Speaking lionhead

The presence of a mane encircling a rabbit's head is certainly an incredible sight. So what causes this and what do we know about it? The mane on a Lionhead is the result of a genetic mutation. MANES ARE NOT CREATED BY THE WOOL GENE that makes angora or wooly rabbits, but an actual mane gene, which is a unique and totally separate gene unto itself. Unlike most other genetic mutations in rabbit fur types, it is a dominant gene. This means you will see its effect on a first generation cross. The current agreed on letter designation for the mane gene is the letter M.

M = mane
m = no mane

There are two possible combinations of the M gene that produce Lionhead manes.
Lionheads with two copies of the mane gene, or what we call double mane (MM), and Lionheads with one copy of the mane gene, or what we call a single mane (Mm). Rabbits without manes are (mm).
At conception, a rabbit will get a copy of either M or m from each parent. Double mane Lionheads can only contribute an M gene. A single mane parent can contribute either an M or an m gene. Non-maned rabbits can only contribute an m gene. The mane gene is a dominant gene, therefore the rabbit needs only one parent to contribute a mane gene (Mm) to have a physical mane. 

If a rabbit has no mane gene (mm) it will NOT have a mane  and will NEVER produce one unless it is bred to a rabbit with a mane. 

(One can argue that a no-maned Lionhead is technically NOT a Lionhead, as they are so named for their mane.)

It is possible that there are additional modifiers seen in some Lionheads that increase density or length and effect texture much the same as you see in other breeds. 

Lionhead Shorthand

When visiting Lionhead websites or chat rooms as well as if you look at some Lionhead pedigrees you will see terms and shorthand notes denoting you may not be familiar with. Some of this information is common genetic coding used in animal breeding for many years but some of the terms are new. These new terms and codes have been devised by breeders to communicate information that there never has been a need to communicate before. This is how truly unusual this breed is!

Lionhead Shorthand and terms -
Lionhead with one gene for the mane. This rabbit will have a mane.
It is called:
- single mane gened
- 1XM (shorthand)
- SMG (abbreviation)

A Lionhead with two genes for the mane. This rabbit will have a mane.
It is called
- Double Mane gened
- two mane genes
- 2XM (shorthand)
- DMG (abbreviation)

A Lionhead with no mane gene. This rabbit will have NO MANE.
It is called
- a slick
- a non maned Lionhead (these can be "purebred Lionheads depending on the breeder and how they handle them in their breeding program)
- a normal fur
- 0MX (shorthand) 

General Genetic Shorthand and Terms -
F1 is a purebred Lionhead crossed with a rabbit of a different breed. Mostly Netherland Dwarf, Polish. In addition some Britannia Petites, Florida Whites, Holland or Mini Lops and Mini Rex have been used. You may also find almost any other breed listed including Dutch, New Zealands and Rex!
It is questionable if a Lionhead hybrid without a mane can be considered a F1 generation because - to be considered a generation the offspring must look like the breed, meeting basic breed requirements. Many Lionhead breeders do count non-maned rabbits that are produced in a F1 Lionhead cross.

F2 is a F1 crossed to a Purebred Lionhead or another hybrid that is F1 or F2. It denotes another generation of Lionhead breeding.

F3 is a F2 bred to a purebred or a F3 or another F2. It denotes you now have three generations of Lionhead breeding before another bred shows on the pedigree.

F4 is the same as purebred. A F3 bred to another F3 or a purebred would produce bunnies with four generations of Lionhead on the pedigree. This is what is required by the ARBA (American Rabbit Breeders Association) to be considered for registration as a PUREBRED if the Lionhead was a recognized breed.

* Some people denote their crosses with percentage number such as 1/2 Lionhead or 3/4 Lionhead but the F system is recognized but almost all animal breeding materials, and is the form most commonly used.
HYBRID is a Lionhead that has rabbits of a breed other then Lionhead showing on a four generation pedigree.
PUREBRED is a rabbit that meets specific breed requirements and has a four generation pedigree showing individual information on each rabbit on the pedigree.
* Currently Lionhead breeders also consider Lionheads imported form overseas as purebred even though most do not have a complete pedigree.