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. 2014 Sep 25;46(1):65.
doi: 10.1186/s12711-014-0065-5.

Two recessive mutations in FGF5 are associated with the long-hair phenotype in donkeys

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Two recessive mutations in FGF5 are associated with the long-hair phenotype in donkeys

Romain Legrand et al. Genet Sel Evol. .

Abstract

Background: Seven donkey breeds are recognized by the French studbook. Individuals from the Pyrenean, Provence, Berry Black, Normand, Cotentin and Bourbonnais breeds are characterized by a short coat, while those from the Poitou breed (Baudet du Poitou) are characterized by a long-hair phenotype. We hypothesized that loss-of-function mutations in the FGF5 (fibroblast growth factor 5) gene, which are associated with a long-hair phenotype in several mammalian species, may account for the special coat feature of Poitou donkeys. To the best of our knowledge, mutations in FGF5 have never been described in Equidae.

Methods: We sequenced the FGF5 gene from 35 long-haired Poitou donkeys, as well as from a panel of 67 short-haired donkeys from the six other French breeds and 131 short-haired ponies and horses.

Results: We identified a recessive c.433_434delAT frameshift deletion in FGF5, present in Poitou and three other donkey breeds and a recessive nonsense c.245G > A substitution, present in Poitou and four other donkey breeds. The frameshift deletion was associated with the long-hair phenotype in Poitou donkeys when present in two copies (n = 31) or combined with the nonsense mutation (n = 4). The frameshift deletion led to a stop codon at position 159 whereas the nonsense mutation led to a stop codon at position 82 in the FGF5 protein. In silico, the two truncated FGF5 proteins were predicted to lack the critical β strands involved in the interaction between FGF5 and its receptor, a mandatory step to inhibit hair growth.

Conclusions: Our results highlight the allelic heterogeneity of the long-hair phenotype in donkeys and enlarge the panel of recessive FGF5 loss-of-function alleles described in mammals. Thanks to the DNA test developed in this study, breeders of non-Poitou breeds will have the opportunity to identify long-hair carriers in their breeding stocks.

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Figures

Figure 1
Figure 1
Long-hair phenotype in Poitou donkeys. Poitou donkeys exhibit lifelong hair growth with young animals usually showing a medium-sized coat with short-hair areas (A, B, C) and adult donkeys showing a long matted and tangled coat (D).
Figure 2
Figure 2
Wild type and mutant FGF5 proteins. (A) Alignment of the FGF5 amino-acid sequence predicted from the equine wild type allele (Wt-FGF5, [Ensembl:ENSECAT00000016512]) and the c.433_434delAT mutant Poitou allele (Po-FGF5). The signal peptide is indicated in bold characters. The secondary structure predicted by the Phyre2 program is represented by the arrows below the Wt-FGF5 sequence. Arrows with numbers represent the 12 β-strands. The predicted N-ter α-helix is indicated. The frameshift produced by the c.433_434delAT deletion is framed. A star indicates the location of the stop codon produced by the c.245G > A nonsense mutation. (B) 3D models built using the Phyre server represent the horse wild type Wt-FGF5 (left) and the donkey c.433_434delAT Poitou Po-FGF5 (right) proteins; the α-helix is highlighted in blue and the β strands are depicted by arrows.

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References

    1. Ozawa K, Suzuki S, Asada M, Tomooka Y, Li AJ, Yoneda A, Komi A, Imamura T. An alternatively spliced fibroblast growth factor (FGF)-5 mRNA is abundant in brain and translates into a partial agonist/antagonist for FGF-5 neurotrophic activity. J Biol Chem. 1998;273:29262–29271. doi: 10.1074/jbc.273.44.29262. - DOI - PubMed
    1. Beenken A, Mohammadi M. The FGF family: biology, pathophysiology and therapy. Nat Rev Drug Discov. 2009;8:235–253. doi: 10.1038/nrd2792. - DOI - PMC - PubMed
    1. Zhan X, Bates B, Hu XG, Goldfarb M. The human FGF-5 oncogene encodes a novel protein related to fibroblast growth factors. Mol Cell Biol. 1988;8:3487–3495. - PMC - PubMed
    1. Hébert JM, Rosenquist T, Götz J, Martin GR. FGF5 as a regulator of the hair growth cycle: evidence from targeted and spontaneous mutations. Cell. 1994;78:1017–1025. doi: 10.1016/0092-8674(94)90276-3. - DOI - PubMed
    1. Suzuki S, Ota Y, Ozawa K, Imamura T. Dual-mode regulation of hair growth cycle by two Fgf-5 gene products. J Invest Dermatol. 2000;114:456–463. doi: 10.1046/j.1523-1747.2000.00912.x. - DOI - PubMed

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