Transcriptomic analysis reveals differentially expressed genes associated with wool length in rabbit

Abstract

Rabbit fur characteristics are primarily genetically determined traits. We used Illumina high-throughput sequencing technology to assess gene expression in the skin tissues of rabbits derived from a cross between Wanxi Angora rabbits and Rex rabbits, which exhibit differential characteristics of short and long wool respectively, to investigate molecular mechanisms related to wool length determination. To identify key regulatory genes involved in rabbit wool length, genes that were differentially expressed between the long- and short-wool rabbits based on a P-value < 0.05 and log |fold change| > 1 were characterized. A total of 798 genes were up-regulated and 523 were down-regulated in the long-wool group compared to expression levels in the short-wool group, and these genes were annotated with GO terms and KEGG pathways, revealing wool-development-related biological functions. The Wnt, Hedgehog and TGF-β signaling pathways, which are related to cell proliferation, fibroblast proliferation and hair follicle regulation respectively, were identified. The expression levels of eight genes were validated by RT-qPCR. In addition, an interaction network was constructed to show the regulatory relationships among the differentially expressed genes. In this study, we found that FGF5, WNT5A, BMP4 and BMP7 showed significant differential expression between the two groups. These transcriptomic profiling results provide comprehensive gene expression information for improving understanding of the molecular mechanisms involved in the growth and development of rabbit wool.

Rabbit Genetic Resources Can Provide Several Animal Models to Explain at the Genetic Level the Diversity of Morphological and Physiological Relevant Traits

“…This gene, assigned to rabbit chromosome 15, was included in the chromosome region in which the Angora locus was located based on segregation analysis followed by microsatellite markers in rabbit families, further supporting the candidacy of FGF5 in this phenotype [111]. Transcriptome analyses based on RNA-seq of skin of long-hair Angora and short-hair Rex rabbits have shown that FGF5 gene expression was upregulated in long-haired rabbits [112,113]. This high FGF5 expression level in Angora rabbits is quite surprising considering that FGF5 has a role in inhibiting hair growth and inducing catagen through a regression of hair follicles [114].…”

Analyses of histological and transcriptome differences in the skin of short-hair and long-hair rabbits

“…FGF5 induced regression of the human hair follicle [38] and knock-out and disruption of FGF5 using the CRISPR/Cas9 system in goat resulted in longer fibres [39, 40]. However, there is a recent report on rabbits indicating that FGF5 was also up-regulated in the long wool group (Wan line Angora rabbit) and down-regulated in the short wool group (Chinchilla Rex rabbit and White Rex rabbit) [41], which was consistent with our findings of RNA-seq and q-PCR, showing that the FGF5 gene was up-regulated in the skin of long-hair rabbit. Previous studies also showed that the polypeptide of FGF5s translated from an alternatively spliced variant of FGF5 mRNA suppressed the activity of FGF5, increasing hair growth [42, 43].…”

Rabbits – their domestication and molecular genetics of hair coat development and quality

“…Rabbit fur and, therefore, wool are formed by keratinocytes, which originate from progenitor populations located at the bottom part of hair follicles (Zhao et al . 2018). These structures are one of the defining anatomical features of mammals and comprise epithelial and mesenchymal cells (Millar 2002; Kim & Yoon 2014; Zhao et al .…”

“…These structures are one of the defining anatomical features of mammals and comprise epithelial and mesenchymal cells (Millar 2002; Kim & Yoon 2014; Zhao et al . 2018; Weir & Garza 2019). At the bottom part of the hair follicle resides a specialized group of cells called the dermal papilla.…”

“…At present, there is a limited number of studies regarding rabbit hair coat development mechanisms, with the most studies on hair growth being focused on humans, sheep and mice (Zhao et al . 2017, 2018). Even then, the most thoroughly researched aspect is hair color.…”