Fibroblast Growth Factor 5 Gene Research Articles

Influence of mutations in the FGF-5 gene on wool performance in sheep (review)

The effect of mutations in the FGF-5 gene on the wool productivity of sheep is considered. The conservation and rational use of the sheep gene pool is a very pressing problem for the development of sheep breeding in modern conditions. Thanks to the widespread use of methods for searching for genome-wide associations, the list of candidate genes for sheep productivity indicators is annually replenished. After identifying a new candidate gene, further work is aimed at a detailed study of its polymorphism and the search for mutations associated with gene expression and economically beneficial animal traits. A promising candidate for the quality indicators of sheep's wool is the hair growth regulator gene FGF-5 (fibroblast growth factor 5). FGF-5 plays a vital role in regulating the hair growth cycle during the development of mammalian hair follicles and skeletal muscle development. Haiyu Zhao et al. conducted a study of FGF-5 gene variation in the SG and SGG sheep populations, according to which ten putative SNPs were identified in the FGF-5 gene, and only five of them could be genotyped (SNPs 1-5). These SNPs are intronic mutations located in the first intron of the ovine FGF-5 gene. It was found that the frequencies of homozygous wild alleles at SNP1, SNP2, SNP3 and SNP5 were higher than those of the mutant alleles, except at the SNP4 locus. This study suggests that the presence of polymorphisms in the FGF-5 gene may affect hair growth in sheep and that hair growth may be enhanced by altering the expression of the FGF5 gene.

Five SNPs Within the FGF5 Gene Significantly Affect Both Wool Traits and Growth Performance in Fine-Wool Sheep (Ovis aries).

Fibroblast growth factor 5 (FGF5) gene, a member of fibroblast growth factor superfamily, plays significant roles in the regulation of the hair growth cycle during the development of mammalian hair follicles as well as the skeletal muscle development. In this study, DNA sequencing was used to scan the putative SNPs within the full-length of FGF5 gene, and SNPscan high-throughput technique was applied in the individual genotyping of 604 crossbred sheep. 10 SNPs were identified within FGF5 gene while five of them located in intron 1 could be genotyped, namely SNP1 (g. 105914953 G > A), SNP2 (g. 105922232 T > C), SNP3 (g. 105922244 A > G), SNP4 (g. 105922334 A > T) and SNP5 (g. 105922340 G > T). All these SNPs were in accord with the Hardy-Weinberg equilibrium (P > 0.05), and displayed the moderate polymorphism with PIC values ranging from 0.302 to 0.374. Thereafter, the correlation analysis between each SNP locus and economic traits including wool length, greasy wool weight and growth performance of sheep was systematically implemented. In our results, SNP1, SNP3, SNP4 and SNP5 were significantly associated with wool length, greasy wool weight and growth traits of SG sheep (P < 0.05); SNP1, SNP2, SNP3, and SNP4 were significantly correlated with wool length and growth traits of SSG sheep (P < 0.05). Meanwhile, our study revealed a strong linkage disequilibrium (LD) relationship among these SNPs (r2 > 0.33), except for SNP3 and SNP4 sites (r2 = 0.30). Combination genotype analysis showed that combination genotypes were significantly associated with mean fiber diameter of SG (P < 0.05), and body weight trait of SSG (P < 0.01). The above findings suggested that these SNP loci might affect economic traits synergistically and could be regarded as potential molecular markers for improving both wool production and growth performance of fine-wool sheep, which lay a molecular foundation for the breeding of fine dual-purpose sheep thereby accelerating the pace of sheep breeding.

Using Genetic Risk Score Approaches to Infer Whether an Environmental Factor Attenuates or Exacerbates the Adverse Influence of a Candidate Gene.

Some candidate genes have been robustly reported to be associated with complex traits, such as the fat mass and obesity-associated (FTO) gene on body mass index (BMI), and the fibroblast growth factor 5 (FGF5) gene on blood pressure levels. It is of interest to know whether an environmental factor (E) can attenuate or exacerbate the adverse influence of a candidate gene. To this end, we here evaluate the performance of “genetic risk score” (GRS) approaches to detect “gene-environment interactions” (G × E). In the first stage, a GRS is calculated according to the genotypes of variants in a candidate gene. In the second stage, we test whether E can significantly modify this GRS effect. This two-stage procedure can not only provide a p-value for a G × E test but also guide inferences on how E modifies the adverse effect of a gene. With systematic simulations, we compared several ways to construct a GRS. If E exacerbates the adverse influence of a gene, GRS formed by the elastic net (ENET) or the least absolute shrinkage and selection operator (LASSO) is recommended. However, the performance of ENET or LASSO will be compromised if E attenuates the adverse influence of a gene, and using the ridge regression (RIDGE) can be more powerful in this situation. Applying RIDGE to 18,424 subjects in the Taiwan Biobank, we showed that performing regular exercise can attenuate the adverse influence of the FTO gene on four obesity measures: BMI (p = 0.0009), body fat percentage (p = 0.0031), waist circumference (p = 0.0052), and hip circumference (p = 0.0001). As another example, we used RIDGE and found the FGF5 gene has a stronger effect on blood pressure in Han Chinese with a higher waist-to-hip ratio [p = 0.0013 for diastolic blood pressure (DBP) and p = 0.0027 for systolic blood pressure (SBP)]. This study provides an evaluation on the GRS approaches, which is important to infer whether E attenuates or exacerbates the adverse influence of a candidate gene.

Crosstalk between androgen and Wnt/\u03b2-catenin leads to changes of wool density in FGF5-knockout sheep

Fibroblast growth factor 5 (FGF5) is a famous dominant inhibitor of anagen phase of hair cycle. Mutations of FGF5 gene result in a longer wool in mice, donkeys, dogs, cats, and even in human eyelashes. Sheep is an important source of wool production. How to improve the production of wool quickly and effectively is an urgent problem to be solved. In this study, we generated five FGF5-knockout Dorper sheep by the CRISPR/Cas9 system. The expression level of FGF5 mRNA in knockout (KO) sheep decreased significantly, and all FGF5 proteins were dysfunctional. The KO sheep displayed a significant increase in fine-wool and active hair-follicle density. The crosstalk between androgen and Wnt/β-catenin signaling downstream of FGF5 gene plays a key role. We established downstream signaling cascades for the first time, including FGF5, FGFR1, androgen, AR, Wnt/β-catenin, Shh/Gli2, c-MYC, and KRTs. These findings further improved the function of FGF5 gene, and provided therapeutic ideas for androgen alopecia.

Expression of Fibroblast Growth Factor 5 (FGF5) and Its Influence on Survival of Breast Cancer Patients.

BackgroundThe clinical outcome of patients with breast cancer (BC) remains poor.Material/MethodsWe analyzed BC microarray studies GSE37751, GSE7390, and GSE21653 to investigate the expression of FGF5 gene between BC patients and their normal counterparts and the relationship between FGF5 expression and age, tumor size, histopathological grading, estrogen receptors, clinical risk group according to St Gallen criteria, clinical risk group according to NPI criteria, clinical risk group according to Veridex signature, distant metastasis-free survival (DMFS), time to distant metastasis (TDM), disease-free survival (DFS), and overall survival (OS) of BC patients. Gene set enrichment analysis (GSEA) was used to investigate the exact mechanisms.ResultsFGF5 expression was significantly upregulated in BC patients relative to that in normal controls (P<0.0001). BC patients in the FGF5 low-expression group were correlated with better clinical characteristics, including tumor size, histopathological grading, estrogen receptors, clinical risk group according to St Gallen criteria, NPI criteria and Veridex signature, DMFS, TDM, and DFS compared with those in the FGF5 high-expression cohort. The result of GSEA indicated that FGF5 inhibits the proliferation of BC cells via ultraviolet response and TGF-β signaling. Quantitative PCR verified that FGF5 was overexpressed in patients with BC.ConclusionsOur results suggest that FGF5 is an independent protective factor for BC patients.

Evidence of post-transcriptional readthrough regulation in FGF5 gene of alpaca

Two different phenotypes are described in alpaca, identified as suri and huacaya, which differ in the type of fleece. The huacaya fleece is characterized by compact, soft and highly crimped fibers, while the suri fleece is longer, straight, less-crimped and lustrous. In our study, the Fibroblast growth factor 5 (FGF5) was investigated as a possible candidate gene for hair length in alpaca (Vicugna pacos). As previously identified in other mammals, our results show that the alpaca FGF5 gene gives rise to a short (FGF5S) and a long (FGF5) isoform. Interestingly, in the long isoform, we observed a point mutation (i.e., a transition C>T at position 499 downstream of the ATG codon) that is able to generate a premature termination codon (PTC). The highly conserved nucleotide and amino acid sequence after PTC suggested a readthrough event (RT) that was confirmed by western blot analysis. The analysis of cDNA sequence revealed motifs and structures of mRNA undergoing RT. In fact, the event is positively influenced by particular signals harbored by the transcript. To the best of our knowledge, this is the first case of a readthrough event on PTC reported for the FGF5 gene and the first case of this translational mechanism in alpaca.

Expression level of fibroblast growth factor 5 (FGF5) in the peripheral blood of primary hypertension and its clinical significance.

ObjectiveTo explore the expression level of FGF5 in the peripheral blood of primary hypertension patients and its clinical significance.MethodsThe 34 patients with primary hypertension treated in this hospital from June 2012 to June 2014 were selected as the observation group, while the 25 patients at this hospital who had physical exam with heathy results were selected as control group. Venous blood was drawn early in the morning after an overnight fast. FGF5, mRNA and protein level changes in the peripheral blood cells and peripheral blood serum were analyzed by real-time fluorescence based quantitative PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). FGF5 gene SNP (rs16998073) were amplified by PCR and inserted into T vector, and its genetic variation were analyzed by sequencing. The relationship of FGF5 protein levels and genetic variation with diastolic/systolic blood pressure was also analyzed.ResultsComparing with the control group, the observation group’s FGF5 mRNA and protein levels significantly increased in the peripheral blood cells and peripheral blood. The difference was statistically significant (P < .05). Correlation analysis showed that FGF5 protein level and systolic/diastolic blood pressure were positively correlated (P < .05). T/A genetic variation of FGF5 gene SNP (rs16998073) and diastolic/systolic blood pressure were positively correlated (P < .05).ConclusionThe FGF5 mRNA and protein expression levels of the patients with primary hypertension were abnormal and had genetic variation, which were associated with blood pressure of the patients with primary hypertension.

Molecular characterization of the llama FGF5 gene and identification of putative loss of function mutations.

Llama, the most numerous domestic camelid in Argentina, has good fiber-production ability. Although a few genes related to other productive traits have been characterized, the molecular genetic basis of fiber growth control in camelids is still poorly understood. Fibroblast growth factor 5 (FGF5) is a secreted signaling protein that controls hair growth in humans and other mammals. Mutations in the FGF5 gene have been associated with long-hair phenotypes in several species. Here, we sequenced the llama FGF5 gene, which consists of three exons encoding 813bp. cDNA analysis from hair follicles revealed the expression of two FGF5 alternative spliced transcripts, in one of which exon 2 is absent. DNA variation analysis showed four polymorphisms in the coding region: a synonymous SNP (c.210A>G), a single base deletion (c.348delA), a 12-bp insertion (c.351_352insCATATAACATAG) and a non-sense mutation (c.499C>T). The deletion was always found together with the insertion forming a haplotype and producing a putative truncated protein of 123 amino acids. The c.499C>T mutation also leads to a premature stop codon at position 168. In both cases, critical functional domains of FGF5, including one heparin binding site, are lost. All animals analyzed were homozygous for one of the deleterious mutations or compound heterozygous for both (i.e. c.348delA, c.351_352insCATATAACATAG/c.499T). Sequencing of guanaco samples showed that the FGF5 gene encodes a full-length 270-amino acid protein. These results suggest that FGF5 is likely functional in short-haired wild species and non-functional in the domestic fiber-producing species, the llama.

CRISPR/Cas9-mediated loss of FGF5 function increases wool staple length in sheep.

Fibroblast growth factor 5 (FGF5) regulates hair length in humans and a variety of other animals. To investigate whether FGF5 has similar effects in sheep, we used clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated 9 (Cas9) to generate loss-of-function mutations with the FGF5 gene in Chinese Merino sheep. A total of 16 lambs were identified with genetic mutations within the targeting locus: 13 lambs had biallelic modifications and three lambs had monoallelic modifications. Characterization of the modifications revealed that 13 were frameshift mutations that led to premature termination, whereas the other three were in-frame deletions. Thus, CRISPR/Cas9 efficiently generated loss-of-function mutations in the sheep FGF5 gene. We then investigated the effect of loss of FGF5 function on wool traits in 12 lambs and found that wool staple length and stretched length of genetically modified (GM) yearling sheep were significantly longer compared with that of wild-type (WT) control animals. The greasy fleece weight of GM yearling sheep was also significantly greater compared with that of WT sheep. Moreover, the mean fiber diameter in GM sheep showed no significant difference compared with WT sheep, suggesting that the increase in greasy fleece weight was likely attributed to the increase in wool length. The results of this study suggest that CRISPR/Cas9-mediated loss of FGF5 activity could promote wool growth and, consequently, increase wool length and yield.

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

BackgroundSeven 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.MethodsWe 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.ResultsWe 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.ConclusionsOur 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.Electronic supplementary materialThe online version of this article (doi:10.1186/s12711-014-0065-5) contains supplementary material, which is available to authorized users.

Isolation, characterization, and expression analysis of FGF5 isoforms in cashmere goat

Fibroblast growth factor 5 (FGF5) is a secreted signaling protein which has been proved to inhibits hair growth and induces catagen in mouse hair follicle in vivo. Shaanbei white cashmere goat (SWCG), a unique genetic resource in China, was used as the subject in this study. The cDNA of FGF5 of SWCG (cgFGF5) was firstly cloned. The length of the open reading frame (ORF) in cgFGF5 was 813bp, encoding a protein of 270 amino acid residues. Our results showed that the cgFGF5 gene expressed one alternative variant, designated as cgFGF5s, which was derived from the cgFGF5 complete transcript via alternative splicing (AS). Analyses of the putative proteins sequences revealed that the same signal peptide was identified in the two transcripts, and the cleavage site was between position 20th and 21st of amino acid residues. A basic FGF domain, which is a characteristic domain of FGFs family, was found in the predictive cgFGF5, but not in the acquired cgFGF5s sequence. Homologous comparison with various species indicated that cgFGF5 gene implied good evolutional conservation in sequence. Analysis using real-time PCR showed that cgFGF5 and cgFGF5s mRNA were both detected in the 12 tissues examined (heart, subcutaneous fat, liver, muscle, spleen, brain, skin, kidney, rumen, large intestine, small intestine and lung). High expression levels of cgFGF5 mRNA were detected in brain, rumen and skin; while cgFGF5s mRNA was highly expressed in subcutaneous fat, heart and skin. In addition, the temporal expression analysis showed that expression of the two transcripts varied throughout hair growth cycle of cashmere goat: mRNA expression of cgFGF5 peaked at telogen; cgFGF5s peaked at catagen, and the lowest level of expressions were both observed at anagen. Results from the present study suggested that FGF5 gene may play a crucial role in cashmere goat hair growth cycle. This study is the first research to provide the primary foundational evidence for further insight into the role of cashmere goat FGF5 gene.

Cloning, expression analysis and RNA interference of &lt;I&gt;FGF5&lt;/I&gt; gene in sheep

The cDNA of fibroblast growth factor 5 (FGF5) gene in sheep was cloned, and the nucleotides sequence homology of FGF5 was compared with other six mammal. In addition, the expression of FGF5 in different tissues was analysed. Gene FGF5 was then recombined into prokaryotic expression vector (pGEX-4T-2) and RNA interference vector (pSilencer 5.1 H1) to study its expression in fibroblast cell lines. Results showed that the open reading frame (ORF) of cDNA in sheep consisted of 813 nucleotide acids encoding 270 amino acids, with the molecular mass of 29.58 kDa and theoretical pI of 10.59. The amino acids sequence of FGF5 gene in sheep shared high identity with those in cow, human, mouse, rat, dog, cat and rabbit. In addition, analysis on tissue expression showed that FGF5 expressed in skin, heart, kidney, liver, pancreas, spleen, lung, and small intestine, especially presenting high levels in skin. The expression of FGF5 in E. coli was induced with IPTG, which produced a protein band with the expected size of 56 kDa on SDS-PAGE, while the expression of FGF5 in sheep fibroblast cell line was knocked down remarkably with the help of integrated RNAi vector.

Confirmation of top polymorphisms in hypertension genome wide association study among Han Chinese

Confirmation of genome wide association (GWA) results in independent samples has recently become new research tendency. We focused on 8 positive top polymorphisms identified in the to-date largest hypertension GWA study and determined whether these polymorphisms were associated with hypertension among Han Chinese. Genotyping was performed among 548 patients diagnosed with essential hypertension and 560 age- and gender-matched controls using ligase detection reactions method. Statistical analyses were conducted using Logistic regression and genotype risk score. Except for a rare polymorphism (rs653178), no deviation from Hardy-Weinberg equilibrium was observed for genotype distributions of others. There was significant differences in the genotype/allele distribution (P=0.006/P=0.002) of rs16998073 in FGF5 (fibroblast growth factor 5) upstream and the allele distribution (P=0.037) of rs16948048 in ZNF652 (zinc finger protein 652) upstream between hypertensive patients and controls. Strong significance was also noted under assumption of different genetic models for the two coalescent polymorphisms, even after controlling covariates of interest. For example, rs16998073 had a 72% increased risk for hypertension under the co-dominant model (95% confidence interval: 1.20-2.45; P=0.003). However, construction of genetic risk scores on common polymorphisms did not reveal any significance with both hypertension and blood pressure, suggesting that contribution of these polymorphisms to hypertension moderate or small in magnitude. Our results implicate variation in FGF5 and ZNF652 gene upstream regions with altered susceptibility to hypertension in Han Chinese.

Genetic variation at hair length candidate genes in elephants and the extinct woolly mammoth

BackgroundLike humans, the living elephants are unusual among mammals in being sparsely covered with hair. Relative to extant elephants, the extinct woolly mammoth, Mammuthus primigenius, had a dense hair cover and extremely long hair, which likely were adaptations to its subarctic habitat. The fibroblast growth factor 5 (FGF5) gene affects hair length in a diverse set of mammalian species. Mutations in FGF5 lead to recessive long hair phenotypes in mice, dogs, and cats; and the gene has been implicated in hair length variation in rabbits. Thus, FGF5 represents a leading candidate gene for the phenotypic differences in hair length notable between extant elephants and the woolly mammoth. We therefore sequenced the three exons (except for the 3' UTR) and a portion of the promoter of FGF5 from the living elephantid species (Asian, African savanna and African forest elephants) and, using protocols for ancient DNA, from a woolly mammoth.ResultsBetween the extant elephants and the mammoth, two single base substitutions were observed in FGF5, neither of which alters the amino acid sequence. Modeling of the protein structure suggests that the elephantid proteins fold similarly to the human FGF5 protein. Bioinformatics analyses and DNA sequencing of another locus that has been implicated in hair cover in humans, type I hair keratin pseudogene (KRTHAP1), also yielded negative results. Interestingly, KRTHAP1 is a pseudogene in elephantids as in humans (although fully functional in non-human primates).ConclusionThe data suggest that the coding sequence of the FGF5 gene is not the critical determinant of hair length differences among elephantids. The results are discussed in the context of hairlessness among mammals and in terms of the potential impact of large body size, subarctic conditions, and an aquatic ancestor on hair cover in the Proboscidea.

Four Independent Mutations in the Feline Fibroblast Growth Factor 5 Gene Determine the Long-Haired Phenotype in Domestic Cats

To determine the genetic regulation of "hair length" in the domestic cat, a whole-genome scan was performed in a multigenerational pedigree in which the "long-haired" phenotype was segregating. The 2 markers that demonstrated the greatest linkage to the long-haired trait (log of the odds > or = 6) flanked an estimated 10-Mb region on cat chromosome B1 containing the Fibroblast Growth Factor 5 (FGF5) gene, a candidate gene implicated in regulating hair follicle growth cycle in other species. Sequence analyses of FGF5 in 26 cat breeds and 2 pedigrees of nonbreed cats revealed 4 separate mutations predicted to disrupt the biological activity of the FGF5 protein. Pedigree analyses demonstrated that different combinations of paired mutant FGF5 alleles segregated with the long-haired phenotype in an autosomal recessive manner. Association analyses of more than 380 genotyped breed and nonbreed cats were consistent with mutations in the FGF5 gene causing the long-haired phenotype in an autosomal recessive manner. In combination, these genomic approaches demonstrated that FGF5 is the major genetic determinant of hair length in the domestic cat.

Expression of the murine fibroblast growth factor 5 gene in the adult central nervous system.

The murine homolog of the fibroblast growth factor-5 (FGF-5) gene has been cloned, and the sequence of the gene's three exons has been determined. The murine gene and the previously isolated human FGF-5 gene are substantially homologous within the coding sequences and in upstream sequences, which contain an additional open reading frame. We have used a portion of the murine gene as probe to detect FGF-5 RNA in adult mouse tissues by both Northern blot and in situ hybridization methods. FGF-5 RNA is present at low levels in widely distributed areas of the central nervous system. Several loci of FGF-5 expression could be localized by in situ hybridization and include portions of the cerebral cortex, hippocampus, and thalamus. Neuronal expression accounts for at least some of the FGF-5 RNA synthesized in the central nervous system.