ABSTRACT

1. Growth performance is significant for chickens. MicroRNAs (miRNAs) have been found to play important roles in the post-transcriptional regulation of skeletal muscle growth. However, the mechanism of miRNAs in this process has not been elucidated.

2. This study involved collecting leg muscle from slow- and fast-growing groups of Bian chicken at 16 weeks of age for high-throughput sequencing. A total of 42 differentially expressed miRNAs (DEMs) were identified. Among them, 22 DEMs were up-regulated and 20 DEMs were down-regulated.

3. Biological process terms, relating to growth, were found by GO enrichment for target genes of DEMs and KEGG pathway analysis of target genes. This revealed some significantly enriched pathways closely related to skeletal muscle development, such as the calcium signalling pathway, ECM-receptor interaction, lysine degradation, apoptosis and tight junctions. Network interaction analysis of DEMs and target genes showed that the top fifty hub genes were targeted by thirteen DEMs.

4. Four important miRNAs (novel_miR_158, novel_miR_144, novel_miR_291, and miR-205a) as well as some other valuable miRNAs, such as gga-miR-214 and gga-miR-3525 were identified. The qPCR results of five DEMs were highly consistent with that of sequencing between the two groups, which proved the reliability of miRNA-seq.

5. The study will help to improve the molecular mechanism of miRNAs in chickens and guide future experiments concerning miRNA function in chicken growth.

摘要

1、鸡的生长性能显着。已发现微小 RNA (miRNA) 在骨骼肌生长的转录后调节中发挥重要作用。然而，miRNA在该过程中的作用机制尚未阐明。

2. 本研究涉及从 16 周龄的慢速和快速生长的卞鸡组中收集腿部肌肉，用于高通量测序。共鉴定出 42 个差异表达的 miRNA (DEM)。其中，22个DEMs上调，20个DEMs下调。

3.通过对DEMs靶基因的GO富集和靶基因的KEGG通路分析，发现与生长相关的生物过程术语。这揭示了一些与骨骼肌发育密切相关的显着丰富的通路，如钙信号通路、ECM-受体相互作用、赖氨酸降解、细胞凋亡和紧密连接。DEMs和靶基因的网络交互分析表明，前50个枢纽基因被13个DEMs靶向。

4.四个重要的miRNA （novel_miR_158，novel_miR_144，新颖_ miR_291，和的miR-205A），以及一些其它的有价值的miRNA，如GGA-的miR-214和GGA-MIR-3525进行了鉴定。5个DEM的qPCR结果与两组测序结果高度一致，证明了miRNA-seq的可靠性。

5. 本研究将有助于完善鸡体内miRNAs的分子机制，为未来有关miRNA在鸡生长中的功能实验提供指导。