Feline long hair – test of FGF5-gene variants

The hair length in cats is controlled by the FGF5-gen (fibroblast growth factor 5). The short fur is the natural hair form in cats (wild-type).

According to Kehler et al., four mutations in FGF5 gene were identified that cause a cat to have long hair – M1(c.356insT), M2 (c.406C>T), M3 (c.474delT) and M4(c.475A>C). Cats that carry two copies of the same mutation (recessive homozygote) or two different mutations of these four mutations (compound heterozygote) have long hair.

The mutation M4 was identified in long-haired cats of all breeds involved in the study, the mutations M1, M2 and M3 are specific for some breed types. The M1 mutation was found in Ragdoll breed. The M2 mutation is prevalent in Norwegian Forest cats and the M3 mutation was identified in Ragdoll breed and Maine Coon cats.

Possible results

• N/N – the cat does not carry any variant specific for long hair – the cat has short hair
• N/M1, N/M2, N/M3, N/M4 – the cat carries one copy of the variant gene – the cat is short-haired, but she can give birth to long-haired offsprings, if suitably crossed.
• M1/M1, M2/M2, M3/M3, M4/M4 – the cat carries two same variants in the FGF5 gene – the cat is long-haired
• N/M1 & N/M2; N/M1 & N/M3; N/M1 & N/M4; N/M2 & N/M3; N/M2 & N/M4; N/M3 & N/M4 – the cat carries two different variants in FGF5 gene – the cat is long-haired on condition that the cat inherited one variant from each parent.

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Reference:

Kehler J. S., V. A. David, A. A. Schaffer, K. Bajema, E. Eizirik, D. K. Ryugo, S. S. Hannah, S. J. O'Brien, M. Menotti-Raymond. Four independent mutations in the feline fibroblast growth factor 5 gene determine the long-haired phenotype in domestic cats. Journal of Heredity 98(6):555-566 (2007).