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

Abstract

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 inframe 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.

Analysis of histological and microRNA profiles changes in rabbit skin development

“…Consequently, we carried out a prediction of target genes and verified that FGF5 was a target gene of conserva-tive_NC_013672.1_9290 and conservative_NC_013675.1_10734 miRNAs. FGF5 serves as a crucial regulator in hair length 35,36 and influences the hair cycle by regulating the anagen-catagen transition 35,[37][38][39] . Our results indicated that conservative_NC_013672.1_9290 and conservative_NC_013675.1_10734 were candidate regulatory miRNAs in the hair cycle.…”

Genomic analysis of the domestication and post-Spanish conquest evolution of the llama and alpaca

“…To further investigate potential function of genes identified in the selection signature analysis, we first focused on a gene within our top ranking admixed locus (in the direction of llama to alpaca), comprising a set of candidate genes for adaptive introgression and artificial selection (ANTXR2/PRDM8/FGF5/C4orf22; see the "Results" section) [99,100] and in particular on FGF5. Since functional variation at FGF5 (also known as the angora gene) is known to correlate with short-or longwool phenotypes in sheep and goat [101,102], we examined sequence differences in this gene in short and longwool alpaca. Six healthy 2 year-old longwool (Suri) alpacas (3:3) and shortwool (Huacaya) alpacas (3:3) were selected for mRNA and protein expression testing using the skin samples.…”

Sheep and Goat Genome Engineering: From Random Transgenesis to the CRISPR Era

“…In sheep, CRISPR/Cas9 has been applied to disrupt the normal function of the FGF5 gene, resulting in 3/18 (16.6%) mutated founders that carried a disruption in FGF5 and showed increased wool length (Hu et al, 2017). Another publication has also reported the generation of FGF5 -disrupted sheep; 16/20 (80%) mutated founders carried both monoallelic and biallelic mutations in FGF5 and showed increased wool length and quantity (Li et al, 2017c). Recently, Zhang et al have also confirmed that the disruption of FGF5 in sheep can lead to an increased wool length and average wool growth rate (Zhang et al, 2019c).…”