RESUMO
The mammalian hair follicle (HF) is a unique, highly regenerative organ with a distinct developmental cycle. Cashmere goat (Capra hircus) HFs can be divided into two categories based on structure and development time: primary and secondary follicles. To identify differentially expressed genes (DEGs) in the primary and secondary HFs of cashmere goats, the RNA sequencing of six individuals from Arbas, Inner Mongolia, was performed. A total of 617 DEGs were identified; 297 were upregulated while 320 were downregulated. Gene ontology analysis revealed that the main functions of the upregulated genes were electron transport, respiratory electron transport, mitochondrial electron transport, and gene expression. The downregulated genes were mainly involved in cell autophagy, protein complexes, neutrophil aggregation, and bacterial fungal defense reactions. According to the Kyoto Encyclopedia of Genes and Genomes database, these genes are mainly involved in the metabolism of cysteine and methionine, RNA polymerization, and the MAPK signaling pathway, and were enriched in primary follicles. A microRNA-target network revealed that secondary follicles are involved in several important biological processes, such as the synthesis of keratin-associated proteins and enzymes involved in amino acid biosynthesis. In summary, these findings will increase our understanding of the complex molecular mechanisms of HF development and cycling, and provide a basis for the further study of the genes and functions of HF development.
Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Redes Reguladoras de Genes , Cabras/genética , Folículo Piloso/metabolismo , Transcriptoma , Animais , Autofagia , Transporte de Elétrons , Feminino , Perfilação da Expressão Gênica , Ontologia Genética , Cabras/crescimento & desenvolvimento , Cabras/imunologia , Folículo Piloso/crescimento & desenvolvimento , Imunidade Inata/genética , Queratinas/genética , Sistema de Sinalização das MAP Quinases/genética , Sistema de Sinalização das MAP Quinases/imunologia , MicroRNAs/genética , Proteínas Mitocondriais/genética , Anotação de Sequência Molecular , Análise de Sequência de RNARESUMO
Previous molecular genetic studies of the goat hair life cycle have focused primarily on a limited number of genes and proteins. To identify additional genes that may play important roles in hair follicle cycle regulation, Illumina sequencing technology was used to catalog differential gene expression profiles in the hair growth cycle (anagen to catagen) of goat, comparing the primary hair follicle with the secondary hair follicle. There were 13,769 and 12,240 unigenes assembled from the reads obtained from primary hair follicle and secondary hair follicle, respectively. Genes encoding keratin proteins and keratin-associated proteins were the most highly expressed. A total of 5899 genes were differentially expressed in anagen vs catagen primary hair follicles, with 532 genes up-regulated and 5367 genes down-regulated. A total of 5208 genes were differentially expressed in anagen vs catagen secondary hair follicle, including 545 genes that were up-regulated and 4663 genes that were down-regulated. Numerous hair growth genes are expressed in the goat hair follicle, of which 73 genes showed co-up-regulation in both hair follicles during the anagen stage. Many of these up-regulated genes, such as STC2, VEGFR, and ROR2, are known to be transfactors in the process of cell differentiation and in the cell cycle. The differential gene expression profiles between primary hair follicles and secondary hair follicles obtained provide a foundation for future studies examining the network of gene expression controlling hair growth cycle in Cashmere goat.