Gene Expression Patterns in Different Wool Densities of Rex Rabbit Using cDNA Microarray

Identification of key genes and signaling pathways related to Hetian sheep wool density by RNA-seq technology

Hetian sheep is a breed of sheep unique to the Hetian area of Xinjiang whose wool is used for producing blankets. Individual differences and hair follicle density are the key factors affecting wool production. Therefore, this study aimed to assess the Hetian sheep having different wool densities to statistically analyze the wool traits and hair follicle parameters. Furthermore, the transcriptome sequencing analysis was performed on the skins with different wool densities. The results showed that wool quantity and total hair follicle density of the high wool density sheep was significantly higher than low wool density sheep. The sheepskin with high wool density was found to grow more and finer wool than sheepskin with low wool density. A total of 1,452 differentially expressed genes were screened from the two sets of samples, including 754 upregulated and 698 downregulated genes. The differentially expressed genes were involved in the TGF-β/BMP and MAPK signaling pathways related to hair growth. Eleven differentially expressed genes belonging to the KAPs and KIFs might affect the fineness of the wool. The key genes, like the TNF, MAP2K2, INHBA, FST, PTPN11, MAP3K7, KIT, and BMPR1A, were found to probably affect the growth and density of the wool. The qPCR verified eight genes related to the MAPK pathway whose gene expression trends were consistent with the transcriptome sequencing results. This study furnishes valuable resources for enhancing the quality and production of wool in the Hetian sheep.

Analysis of histology and long noncoding RNAs involved in the rabbit hair follicle density using RNA sequencing

BACKGROUND

Hair follicle density influences wool fibre production, which is one of the most important traits of the Wan Strain Angora rabbit. However, molecular mechanisms regulating hair follicle density have remained elusive.

RESULTS

In this study, hair follicle density at different body sites of Wan Strain Angora rabbits with high and low wool production (HWP and LWP) was investigated by histological analysis. Haematoxylin-eosin staining showed a higher hair follicle density in the skin of the HWP rabbits. The long noncoding RNA (lncRNA) profile was investigated by RNA sequencing, and 50 and 38 differentially expressed (DE) lncRNAs and genes, respectively, were screened between the HWP and LWP groups. A gene ontology analysis revealed that phospholipid, lipid metabolic, apoptotic, lipid biosynthetic, and lipid and fatty acid transport processes were significantly enriched. Potential functional lncRNAs that regulate lipid metabolism, amino acid synthesis, as well as the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) and hedgehog signalling pathways, were identified. Consequently, five lncRNAs (LNC_002171, LNC_000797, LNC_005567, LNC_013595, and LNC_020367) were considered to be potential regulators of hair follicle density and development. Three DE lncRNAs and genes were validated by quantitative real-time polymerase chain reaction (q-PCR).

CONCLUSIONS

LncRNA profiles provide information on lncRNA expression to improve the understanding of molecular mechanisms involved in the regulation of hair follicle density.

Polymorphisms of exon 5, exon 7 and intron 10 of MMP2 gene and their association with wool density in Rex rabbits

<p>Wool density is an important index that influences Rex rabbit fur quality. In our earlier studies, we found some important differentially expressed genes in different wool density of Rex rabbit by cDNA microarray. Based on the outcome, we conducted an association study to identify single nucleotide polymorphisms (SNPs) of exon 1, 5, 7 and 10 of matrix metalloproteinase-2 (MMP2) gene and their ligands associated with wool density. The results showed that exon 1 and exon 10 of MMP2 gene did not occur mutation in 100 Rex rabbits, meanwhile 3 SNPs were identified in exon 5, exon 7 and intron 10 of MMP2 gene sequence respectively, the 3 mutation sites were as follows: MMP2-exon 5-26C/G, MMP2-exon 7-101C/T and MMP2-intron 10-6C/T. The 3 SNPs were all in Hardy-Weinberg equilibrium. Phenotypic correlation analysis results showed the 3 mutations lacked significant associations (P&gt;0.05) with the wool density.</p>