A 1-bp deletion in Fgf5 causes male-dominant long hair in the Syrian hamster

Abstract

Hair length in mammals is generally regulated by the hair cycle, and its disruption leads to abnormal hair morphogenesis in several species. FGF5, one of the hair cycle regulators, has a role in inducing catagen, and that mutation causes abnormal hair length in both sexes in humans, mice, dogs, and cats. Male-dominant long-haired coat (MALC) is an inbred strain of Syrian hamster exhibiting spontaneous long hair in males. After castration, MALC exhibited significantly shorter hair than the control individuals, but testosterone administration to castrated MALC showed reversion to the original phenotype. Moreover, flutamide administration led to MALC phenotype repression. Histological analysis revealed that hair follicle regression was shown in the wild-type 4 weeks after depilation, but that of MALC remained in the anagen phase. We detected a c.546delG of Fgf5 in MALC (Fgf5malc) that might lead to truncation resulting from a frame shift in FGF5 (p.Arg184GlyfsX6). Additionally, homozygous Fgf5malc was only detected in long-haired (Slc:Syrian×MALC)F2 and (J-2-Nn×MALC)F2 progenies, and all homozygous wild and heterozygous Fgf5malc individuals showed normal hair length. Thus, Fgf5malc leads to male-dominant long hair via a prolonged anagen phase which is affected by testosterone in hamsters. To our knowledge, this report is the first to present the sexual dimorphism of hair length caused by the Fgf5 mutation.

Highly efficient base editing with expanded targeting scope using SpCas9‐NG in rabbits

“…21 It has been demonstrated that the Fgf5 gene negatively regulates hair length in humans 22 and a variety of other mammal species such as mice, 23 dogs, 24 and goats. Hair length is a critical economic trait in rabbits because it is closely associated with hair productivity.…”

“…3 CBEs and ABEs, composed of a cytidine deaminase or an evolved adenine deaminase fused to Cas9 nickase (nCas9), enable the conversion of C·G to T·A or A·T to G·C base pair in organisms, respectively. 6 Efficient base editing requires the presence of a NGG PAM that places the target C within an ~5-nucleotide window near the PAM-distal end of the protospacer (positions 4-8, counting the PAM as positions [21][22][23] in human cells. 6 Efficient base editing requires the presence of a NGG PAM that places the target C within an ~5-nucleotide window near the PAM-distal end of the protospacer (positions 4-8, counting the PAM as positions [21][22][23] in human cells.…”

“…4,5 Additionally, the recently developed base editors, BE4max and ABEmax, can significantly increase editing efficiency by modifying nuclear localization signals (NLS) and codon usage. 6 Efficient base editing requires the presence of a NGG PAM that places the target C within an ~5-nucleotide window near the PAM-distal end of the protospacer (positions 4-8, counting the PAM as positions [21][22][23] in human cells. 4,5 Therefore, the NGG PAM requirement of SpCas9 substantially limits the target sites suitable for base editing.…”

Social context modulates food hoarding in Syrian hamsters

“…Syrian hamsters build larder hoards and defend them against competitors (Gismonoli, 1999;Lupfer, Frieman & Coonfield, 2003). Golden Syrian hamsters are the domestic variety most similar to the wild type at the phenotypic and behavioral level; while long-haired Syrian hamsters are a domestic variety selected by its long hair and low aggression level (Yoshizawa et al, 2015). The aim of the present study was to evaluate the extent to which changes in the social environment affect food hoarding strategies in two varieties of Syrian hamster.…”

A nonsense mutation in the FGF5 gene is associated with the long‐haired phenotype in domestic guinea pigs (Cavia porcellus)

“…In mammals, the disruption of hair growth regulation can result in abnormal hair morphogenesis. Mutations in the FGF5 gene encoding fibroblast growth factor 5, which plays an important role in inducing catagen, have been associated with long‐haired phenotypes in Syrian hamsters, dogs, cats, donkeys and llamas . Domestic guinea pigs ( Cavia porcellus ) with long hair are very popular as pets in many countries because of their appealing appearance (Fig.…”