Construction of a cDNA library and identification of genes from Liaoning cashmere goat

Polymorphisms and mRNA Expression Levels of IGF-1, FGF5, and KAP 1.4 in Tibetan Cashmere Goats

The Tibetan cashmere goat is a precious breed in China and its cashmere is widely used in clothing and textiles. The genes IGF-1, FGF5, and KAP 1.4 have been shown to be crucial regulators of cashmere growth. In this study, we examined mRNA expression levels of these three genes and detected IGF-1, FGF5, and KAP 1.4 SNP loci in the Tibetan cashmere goat. After amplification and sequence alignment of the genes IGF-1, FGF5, and KAP 1.4 among 206 Tibetan cashmere goats, two new SNP loci were detected in gene KAP 1.4, while no SNP loci were found in amplified fragments of genes IGF-1 and FGF5. The expression levels of gene IGF-1 in Baingoin and Nyima counties were significantly higher than in other counties (p < 0.05). Moreover, the expression level of gene FGF5 in Gêrzê was significantly higher than in Rutog. The expression levels of mRNA in KAP 1.4 showed significant variation among seven counties. There were no significant differences in mRNA expression levels of IGF-1, FGF5, and KAP 1.4 in Tibetan cashmere goats when analysed by sex. The gene IGF-1 was slightly up-regulated in one to five-year-old cashmere goats, except in those that were 4 years old. The mRNA expression levels of FGF5 in one and two-year-old cashmere goats was lower compared with those in three to five-year-old cashmere goats. KAP 1.4 was up-regulated across one to five-year-old cashmere goats. In this study, SNP detection and mRNA expression analysis of IGF-1, FGF5, and KAP 1.4 genes was able to add data to genetic evolutionary analysis. Further studies should be carried out in SNPs to detect other fragments in genes IGF-1 and FGF5, as well as signal pathways and gene functions in protein levels of genes IGF-1, FGF5, and KAP 1.4 in the Tibetan cashmere goat.

Comprehensive analysis of circRNAs from cashmere goat skin by next generation RNA sequencing (RNA-seq)

Circular RNA (circRNA) is endogenous non-coding RNA (ncRNA) with a covalently closed circular structure. It is mainly generated through RNA alternative splicing or back-splicing. CircRNA is known in the majority of eukaryotes and very stable. However, knowledge of the circRNA involved in regulating cashmere fineness is limited. Skin samples were collected from Liaoning cashmere goats (LCG) and Inner Mongolia cashmere goats (MCG) during the anagen period. For differentially expressed circRNAs, RNA sequencing was performed, and the analysis led to an identification of 17 up-regulated circRNAs and 15 down-regulated circRNAs in LCG compared with MCG skin samples. In order to find the differentially expressed circRNAs in LCG, we carried out qPCRs on 10 candidate circRNAs in coarse type skin of LCG (CT-LCG) and fine type skin of LCG (FT-LCG). Four circRNAs: ciRNA128, circRNA6854, circRNA4154 and circRNA3620 were confirmed to be significantly differential expression in LCG. Also, a regulatory network of circRNAs-miRNAs was bioinformatically deduced and may help to understand molecular mechanisms of potential circRNA involvement in regulating cashmere fineness.

Cashmere growth control in Liaoning cashmere goat by ovarian carcinoma immunoreactive antigen-like protein 2 and decorin genes

Objective

The study investigated the biological functions and mechanisms for controlling cashmere growth of Liaoning cashmere goat by ovarian carcinoma immunoreactive antigen-like protein 2 (OCIAD2) and decorin (DCN) genes.

Methods

cDNA library of Liaoning cashmere goat was constructed in early stages. OCIAD2 and DCN genes related to cashmere growth were identified by homology analysis comparison. The expression location of OCIAD2 and DCN genes in primary and secondary hair follicles (SF) was performed using in situ hybridization. The expression of OCIAD2 and DCN genes in primary and SF was performed using real-time polymerase chain reaction (PCR).

Results

In situ hybridization revealed that OCIAD2 and DCN were expressed in the inner root sheath of Liaoning cashmere goat hair follicles. Real-time quantitative PCR showed that these genes were highly expressed in SF during anagen, while these genes were highly expressed in primary hair follicle in catagen phase. Melatonin (MT) inhibited the expression of OCIAD2 and promoted the expression of DCN. Insulin-like growth factors-1 (IGF-1) inhibited the expression of OCIAD2 and DCN, while fibroblast growth factors 5 (FGF5) promoted the expression of these genes. MT and IGF-1 promoted OCIAD2 synergistically, while MT and FGF5 inhibited the genes simultaneously. MT+IGF-1/MT+FGF5 inhibited DCN gene. RNAi technology showed that OCIAD2 expression was promoted, while that of DCN was inhibited.

Conclusion

Activation of bone morphogenetic protein (BMP) signaling pathway up-regulated OCIAD2 expression and stimulated SF to control cell proliferation. DCN gene affected hair follicle morphogenesis and periodic changes by promoting transforming growth factor-β (TGF-β) and BMP signaling pathways. OCIAD2 and DCN genes have opposite effects on TGF-β signaling pathway and inhibit each other to affect the hair growth.

Effects of melatonin implantation on cashmere growth, hormone concentrations and cashmere yield in cashmere-perennial-type Liaoning cashmere goats

The aim of the present study was to investigate the effects of melatonin implants on cashmere growth, the concentrations of plasma melatonin and prolactin and the total cashmere yield in cashmere-perennial-type Liaoning cashmere goats. Twenty female goats were assigned to two treatments (n = 10) including a control and a treatment in which melatonin (2 mg/kg bodyweight) was implanted in March and May, respectively. The experiment lasted for 153 days. Fibre samples were collected in July, August and April the following year (before cashmere harvest). Blood samples were taken monthly from March to August. Cashmere yield was recorded after harvest. In melatonin-treated goats, cashmere length and cashmere growth rate from April to July were significantly increased (P < 0.05), but no influence was observed (P > 0.05) in August. Implantation of melatonin significantly increased plasma melatonin concentrations (P < 0.05) and decreased prolactin concentrations from April to July compared with the control group (P < 0.05), but no difference was observed in August (P > 0.05). Administration of melatonin increased the cashmere yield by 6.2% and the maximum cashmere length by 8.4%, but the differences were not significant (P > 0.05). Moreover, the cashmere fibre diameter was not influenced by melatonin implantation (P > 0.05). The results also indicated that plasma melatonin concentrations were correlated with plasma prolactin in the regulation of cashmere growth. Implantation of melatonin was an effective way to promote cashmere growth, and administration during the cashmere slow-growing period improved cashmere production without changing cashmere fibre diameter in cashmere-perennial-type Liaoning cashmere goats.