Zhang Sihuan, Xu Han, Liu Xinfeng, Yang Qing, Pan Chuanying, Lei Chuzhao, Dang Ruihua, Chen Hong, Lan Xianyong
College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, People's Republic of China.
R Soc Open Sci. 2017 Dec 20;4(12):171415. doi: 10.1098/rsos.171415. eCollection 2017 Dec.
In practical production, almost all rams and about 50% of ewes are used to fatten. Researchers have proved that ewe ovariectomy could improve the productivity significantly, but the specific molecular mechanism is still unknown. In this study, five independent cDNA libraries (three and two from ovariectomized and normal ewe longissimus dorsi samples, respectively) were constructed to thoroughly explore the global transcriptome, further to reveal how the ovariectomized ewes influence muscle development by Illumina2000 sequencing technology. As a result, 205 358 transcripts and 118 264 unigenes were generated. 15 490 simple sequence repeats (SSRs) were revealed and divided into six types, and the short repeat sequence SSR (monomers, dimers, trimers) was the domain type. Single nucleotide polymorphism analysis found that the number of transition was greater than the number of transversion among the five libraries. Furthermore, 1612 differently expressed genes (DEGs) (Log2fold_change > 1 and < 0.05) were revealed between ovariectomized and normal ewe groups, in which 903 genes were expressed commonly in the two groups, and 288 and 421 genes were uniquely expressed in normal and ovariectomized ewe groups, respectively. Gene Ontology (GO) analysis categorized all unigenes into 555 GO terms and 56 DEGs were significantly categorized into 43 GO terms (< 0.05). KEGG enrichment analysis annotated 12 976 genes (containing 137 DEGs) to 86 pathways, among them 24 and 11 DEGs involved in development and reproduction associated pathways, respectively. To validate the reliability of the RNA-seq analysis, 22 candidate DEGs were randomly selected to perform quantitative real-time polymerase chain reaction. The result showed that 9 and 1 genes were significantly and approximately significantly expressed in control and treatment group, respectively, and the results of RNA-seq are believable in this study. Overall, these results were helpful for elucidating the molecular mechanism of muscle development of ovariectomized animals and the application of female ovariectomy in fattening.
在实际生产中，几乎所有的公羊和约50%的母羊都用于育肥。研究人员已证明母羊卵巢切除可显著提高生产力，但具体分子机制仍不清楚。本研究构建了五个独立的cDNA文库（分别来自卵巢切除和正常母羊背最长肌样本的文库各三个和两个），以全面探索整体转录组，进而通过Illumina2000测序技术揭示卵巢切除母羊如何影响肌肉发育。结果，共产生了205358个转录本和118264个单基因。揭示了15490个简单序列重复（SSR），并分为六种类型，短重复序列SSR（单体、二聚体、三聚体）为优势类型。单核苷酸多态性分析发现，五个文库中转换的数量多于颠换的数量。此外，卵巢切除和正常母羊组之间共揭示了1612个差异表达基因（DEG）（Log2倍数变化>1且<0.05），其中903个基因在两组中共同表达，288个和421个基因分别在正常和卵巢切除母羊组中特异性表达。基因本体（GO）分析将所有单基因分类为555个GO术语，56个DEG显著分类为43个GO术语（<0.05）。KEGG富集分析将12976个基因（包含137个DEG）注释到86条通路，其中分别有24个和11个DEG参与发育和繁殖相关通路。为验证RNA测序分析的可靠性，随机选择22个候选DEG进行定量实时聚合酶链反应。结果表明，分别有9个和1个基因在对照组和处理组中显著和近似显著表达，本研究中RNA测序结果可信。总体而言，这些结果有助于阐明卵巢切除动物肌肉发育的分子机制以及雌性卵巢切除在育肥中的应用。
