转录组测序揭示细胞周期通路参与鸡腹脂沉积

近年来,随着生长性状和饲料转化率的提高,中国地方品种肉鸡腹脂率不断增加,大大降低了肉鸡的品质。过多的腹脂沉积不仅降低了肉鸡的屠宰率和抗病力,而且由于脂肪较难处理,导致其被随意丢弃,污染环境。为了挖掘与中国地方品种肉鸡腹脂沉积相关的基因和调控通路,本研究对杏花鸡分别进行高脂和普通饲料的喂养,检测腹脂沉积情况,并利用转录组测序检测高脂饲养对肝脏和腹脂组织中基因表达的影响。结果表明,喂养两周后高脂组肉鸡腹脂重和腹脂率显著增加,且腹脂细胞的直径和面积也显著增大。对两组鸡的腹脂和肝脏进行转录组测序,发现在腹脂中显著差异表达基因主要富集于细胞周期通路、PPAR(peroxisome proliferator-activated receptor)信号通路和ECM(extracellular matrix)受体信号通路中;而在肝脏中,显著差异表达基因同样显著富集于细胞周期通路中,同时也显著富集于类固醇生物合成和PPAR信号通路中。通过分析腹脂和肝脏组织中共同差异表达的基因,发现这些基因同样显著富集于细胞周期中。进一步以鸡肝癌细胞系LMH(chicken hepatoma cell)细胞和鸡前脂肪细胞系ICP(immortalized chicken preadipocytes)细胞进行体外验证,利用高脂培养基和普通培养基进行培养,结果发现48h后,高脂培养基可显著促进细胞周期进程,增加处于S期的细胞数。同时,qRT-PCR结果发现高脂培养基可显著促进细胞周期相关基因的表达。综上所述,本研究通过基因表达差异分析,发现高脂饲养可能通过激活鸡脂肪组织的细胞周期来促进前脂肪细胞增殖,进而增加腹脂沉积。该研究结果为进一步了解优质肉鸡腹脂沉积的机制提供了理论依据。

Transformer’s Condition Assessment Method Based on Combination of Cloud Matter Element and Principal Component Analysis

With the development of power grid, as one of the key equipment, the transformer’s condition assessment method has always receive attention from experts, scholars concern more and more about the method’s practicality and reliability. In the traditional condition assessment method, due to the characteristics of the transformer’s complex structure, the assessment system is not comprehensive enough, or the assessment system is too complex, the indexes are not easy to quantify, such problems are emerging. The traditional method is complex and the degree of quantification is not enough. Therefore it is necessary to propose a condition assessment method that is easy to carry out the condition assessment work and does not affect the assessment results. In this paper, we propose a method to assess the state of the transformer’s complex structure. First, we establish a comprehensive assessment system, then apply the method of principal component analysis to optimize the index system, and then use the theory of cloud-matter-element. Finally the reliability and rationality of the method are verified by an example.