去势对淮南公猪背最长肌转录组的影响

Effect of Castration on Gene Expression in Longissimus dorsi Muscle of Huainan Male Pig by Transcriptome Analysis

旨在分析去势对猪背最长肌基因表达的影响,探讨去势对肉质性状的分子调控机制。本研究将6头健康公猪分为两组,去势组和非去势组(对照组),在体重达到130 kg时(大约300~315日龄)采集背最长肌样品,利用Illumina HiSeq 2000高通量RNA-seq测序技术对两组猪背最长肌进行转录组测序,使用DESeq软件筛选差异表达基因,并在GO和KEGG数据库中对这些差异表达基因进行功能注释和富集分析。结果显示,去势和非去势淮南公猪分别获得83 613 018和83 746 508条可用读段,与猪参考基因组(Sscrofa10.2)的比对率分别为73.78%和74.09%。与非去势组相比,去势后共有差异表达基因935个,其中上调基因503个,下调基因432个(P<0.05且|log2(Fold Change)|>0.8)。其中与肌肉发育相关上/下调最显著的基因分别是胶原蛋白XI型α1(COL11A1)和血管紧张素Ⅱ1型受体(AGTR1),而与脂肪代谢相关上/下调最显著的基因分别是硬脂酰辅酶A去饱和酶1(SCD-1)和脂肪特异性磷脂酶A2(PLA2G16)。GO和KEGG通路分析发现,两组差异表达基因显著富集于胰岛素、脂解、脂肪酸延长等脂质代谢相关通路,以及肾上腺素能、心肌收缩、磷酸腺苷活化的蛋白激酶等肌肉发育相关通路。本研究表明,去势后公猪脂肪沉积能力增强,肌肉发育改变,肉质性状随之改变。SCD-1、激素敏感脂酶(HSL)、葡萄糖转运体4(GLUT4)、丝氨酸/苏氨酸激酶(AKT)、促分裂原活化蛋白激酶(MEK)等12个差异表达基因能同时或部分参与激素分泌、脂肪沉积和肌肉发育的调控,这些基因与去势后肉质性状的改变显著相关,值得进行进一步的功能验证。

The aim of this study was to detect the influence of castration on gene expression in porcine longissimus dorsi(LD) muscle and reveal the molecular regulation mechanism of castration on porcine meat quality. Six healthy Huainan male pigs were divided into 2 groups, castrated group and intact group(control group), the LD muscle was collected when their body weight achieved 130 kg(300-315 days of age). The LD muscle transcriptomes of pigs in the 2 groups were analyzed by Illumina HiSeq 2000 high-throughput RNA sequencing system. The differentially expressed genes were screened using DESeq software. All of differentially expressed genes were annotated by using GO and KEGG databases. The results showed that 83 613 018 and 83 746 508 reads were obtained from the castrated and intact groups, respectively. And the ratios of these reads to porcine reference genome(Sscrofa10.2) were 73.78% and 74.09%, respectively. Compared with intact pigs, there were 935 differentially expressed genes in LD muscle of castrated pigs, of which 503 up-regulated genes and 432 down-regulated genes(P<0.05 and |log2(Fold Change)|>0.8). The top up-and down-regulated differentially expressed genes associated with muscle development were collagen type XI alpha 1 chain(COL11 A1) and angiotensin II receptor type 1(AGTR1) in castrated group vs intact group. Similarly, the top up-and down-regulated differentially expressed genes associated with lipid metabolism were stearoyl-coA desaturase 1(SCD-1) and phospholipase A2 group XVI(PLA2 G16). GO and KEGG analysis showed that the differentially expressed genes were mainly associated with lipid metabolism(like insulin, lipolysis, fatty acid elongation) and muscular development(such as adrenergic signaling, muscle contraction, AMPK signaling pathway) related pathways. In conclusion, castration can increase male pigs’ lipid deposition, change muscular development and meat quality. There were 12 differentially expressed genes, including SCD-1, hormone-sensitive lipase(HSL), glucose transporter type 4(GLUT4), serine/threonine kinase(AKT), mitogen-activated protein kinase(MEK), and so on. It was reported that these genes could regulate hormone secretion, muscle development and lipid deposition. These genes were significantly associated with the alteration of meat quality in porcine after castration, so they were worth of further functional verification.