Identification and molecular analysis of cashmere goat lncRNAs reveal their integrated regulatory network and potential roles in secondary hair follicle

N6-Methyladenosine modification (m6A) of circRNA-ZNF638 contributes to the induced activation of SHF stem cells through miR-361-5p/Wnt5a axis in cashmere goats

OBJECTIVE

The objective of this study was to investigate the effects of N6-Methyladenosine modification-circRNA-zinc finger protein 638 (m6A-circRNA-ZNF638) on the induced activation of secondary hair follicle (SHF) stem cells with its potential mechanisms in cashmere goats.

METHODS

The m6A modification of ZNF638 was analyzed using methylation immunoprecipitation with real-time quantitative polymerase chain reaction technique in SHF stem cells. The effects of circRNA-ZNF638 on the induced activation of SHF stem cells in m6A dependence were evaluated through the overexpression of circRNA-ZNF638/its m6Adeficient mutants in circRNA-ZNF638 knockdown SHF stem cells. The competitive binding of miR-361-5p to circRNA-ZNF638/Wnt5a 3'- untranslated region was analyzed through Dual-luciferase reporter assay.

RESULTS

The m6A-circRNA-ZNF638 had significantly higher transcription at anagen SHF bulge of cashmere goats compared with that at telogen, as well as it positively regulated the induced activation of SHF-stem cells in cashmere goats. Mechanismly, m6A-circRNA-ZNF638 sponged miR-361-5p to heighten the transcriptional expression of Wnt5a gene in SHFstem cells. We further demonstrated that the internal m6A modification within circRNAZNF638 is required for mediating the miR-361-5p/Wnt5a pathway to regulate the induced activation of SHF stem cells through an introducing of m6A-deficient mutant of circRNAZNF638.

CONCLUSION

The circRNA-ZNF638 contributes the proper induced activation of SHF-stem cells in cashmere goats in m6A-dependent manner through miR-361-5p/Wnt5a axis.

Identification and Molecular Analysis of m6A-circRNAs from Cashmere Goat Reveal Their Integrated Regulatory Network and Putative Functions in Secondary Hair Follicle during Anagen Stage

Simple Summary

Cashmere is a natural, high-end textile material. It is derived from the secondary hair follicle (SHFs) tissue in the skin of cashmere goats. Previous studies have indicated that m⁶A modifications in circRNA molecules play important roles in a variety of cells through multiple mechanisms. However, little information is available on the expression profile and functional regulatory characteristics of m⁶A-modified circRNA (m⁶A-circRNA) in SHFs of cashmere goats. In this study, a total of 15 m⁶A-circRNAs were identified. Six of these m⁶A-circRNAs were revealed to have significantly higher expression in skin at anagen than at telogen. To gain insight into the potential regulatory mechanisms of the anagen up-regulated m⁶A-circRNAs, we constructed the regulatory networks along with related pathways in SHFs of cashmere goats. In addition, we found that the expression trends of four m⁶A-circRNAs in the SHFs during SHF cycles were highly similar to their host genes. However, the expression patterns of two m⁶A-circRNAs were inconsistent with the linear RNAs from their host genes in the SHFs of cashmere goats. These results will provide new insights to elucidate the biological functions and regulatory features of m⁶A-circRNA in SHF development and cashmere growth in goats.

Abstract

N⁶-methyladenosine (m⁶A) is the most abundant modification in linear RNA molecules. Over the last few years, interestingly, many circRNA molecules are also found to have extensive m⁶A modification sites with temporal and spatial specific expression patterns. To date, however, little information is available concerning the expression profiling and functional regulatory characteristics of m⁶A modified circRNAs (m⁶A-circRNAs) in secondary hair follicles (SHFs) of cashmere goats. In this study, a total of fifteen m⁶A-circRNAs were identified and characterized in the skin tissue of cashmere goats. Of these, six m⁶A-circRNAs were revealed to have significantly higher expression in skin at anagen compared with those at telogen. The constructed ceRNA network indicated a complicated regulatory relationship of the six anagen up-regulated m⁶A-circRNAs through miRNA mediated pathways. Several signaling pathways implicated in the physiological processes of hair follicles were enriched based on the potential regulatory genes of the six anagen up-regulated m⁶A-circRNAs, such as TGF-beta, axon guidance, ribosome, and stem cell pluripotency regulatory pathways, suggesting the analyzed m⁶A-circRNAs might be essentially involved in SHF development and cashmere growth in cashmere goats. Further, we showed that four m⁶A-circRNAs had highly similar expression trends to their host genes in SHFs of cashmere goats including m⁶A-circRNA-ZNF638, -TULP4, -DNAJB6, and -CAT. However, the expression patterns of two m⁶A-circRNAs (m⁶A-circRNA-STAM2 and -CAAP1) were inconsistent with the linear RNAs from their host genes in the SHFs of cashmere goats. These results provide novel information for eluci-dating the biological function and regulatory characteristics of the m⁶A-circRNAs in SHF development and cashmere growth in goats.

Association analysis for SNPs of KRT26 and TCHH genes with cashmere production performance, body measurement traits and milk production traits in Liaoning cashmere goats

Cashmere fineness is getting thicker, which is one of the key problems in cashmere breeding, however, there have been no systematic studies on the molecular regulation of cashmere fineness. The aim of this study was to investigate the relationship between KRT26 and TCHH gene polymorphism and production performance in Liaoning cashmere goats (LCG). The potential single nucleotide polymorphisms (SNPs) of LCG were detected by sequence alignment and PCR-Seq polymorphism of KRT26 and TCHH genes and analyzed the effect of SNPs on production performance by SPSS software. Two SNPs sites (A559T and A6839G) of two genes were detected. The AA genotype of KRT26 A559T locus was the dominant genotype. AG and GG at TCHH A6839G locus were the dominant genotypes. AAAA was the dominant haplotype combination. The results showed that KRT26 and TCHH genes were associated with cashmere fineness of LCG, and A559T (AA) and A6839G (GG) genotypes were the preferred marker genotypes for cashmere fineness, which provided more theoretical basis for further research on cashmere fineness.