葡萄糖诱导线虫脂肪沉积的表观遗传学研究

发布时间：2018-08-17 18:36

【摘要】：肥胖是一种影响机体健康的代谢疾病,饮食诱导的肥胖是肥胖研究的主要模型。表观遗传是DNA序列不改变的条件下,发生的可遗传的变异。研究肥胖的表观遗传学问题,首先要确定脂肪沉积是否为可遗传的表观遗传现象。是本研究以线虫作为肥胖模型,高浓度的葡萄糖可以诱导线虫脂肪沉积增加。选取秀丽隐杆线虫为研究对象有以下原因：生长周期短、较大的孵化率、遗传操作简单,突变体种类齐全,RNA干扰容易实现。对线虫进行高浓度葡萄糖饮食诱导,再进行普通饮食的饲喂,发现脂肪沉积增加具有表观遗传现象。我们选取了1 mM和5 mM葡糖糖,分别对野生型N2线虫诱导2代,诱导的第二代定义为P0,之后线虫在普通培养基上饲喂。发现两个浓度的葡糖糖诱导均引起的脂肪沉积的增加。这种脂肪沉积的增加至少可以遗传5代,转入普通饮食饲喂的线虫分别称为F1、F2、F3、F4、F5。而且1 mM葡萄糖诱导后与普通饮食的对照组相比,脂肪沉积的增加在各代均达到了显著水平。运用定量PCR检测PO至F5代线虫β一氧化相关基因的表达,发现有些基因的表达发生了显著变化。进一步说明,确定了脂肪沉积具有表观遗传的现象。在线虫中表观遗传与组蛋白甲基化修饰以及组蛋白乙酰化修饰相关。定量PCR分别检测了这几个修饰相关的关键基因,发现组蛋白甲基化修饰和乙酰化修饰基因的表达量显著变化。线虫的遗传背景的改变影响线虫的脂肪沉积,在突变体tph-1中进行1 mM葡萄糖诱导,发现这个突变体的脂肪沉积增加不具有表观遗传现象。说明血清素信号通路,可能影响线虫脂肪沉积的表观遗传。综上所述。mM和5 mM葡萄糖诱导的野生型N2线虫脂肪沉积的增加,具有表观遗传现象。因为,1 mM葡糖糖诱导的线虫脂肪沉积在各代的均显著增加。因此,选取1 mM葡糖糖诱导即可达到实验目的。定量PCR检测β-氧化相关基因,也得到了证实。检测与表观遗传相关的组蛋白修饰的关键基因的表达,发现线虫脂肪沉积的表观遗传受组蛋白的甲基化修饰以及乙酰化修饰影响。通过tph-1突变体的实验,证明血清素信号通路可能影响了线虫脂肪沉积的表观遗传。
[Abstract]:Obesity is a metabolic disease that affects the health of the body. Diet induced obesity is the main model of obesity research. Epigenetics is a heritable variation that occurs under the condition that the DNA sequence does not change. To study the epigenetic problem of obesity, it is necessary to determine whether fat deposition is an epigenetic phenomenon. In this study, nematodes were used as obesity models, and high glucose could induce increased fat deposition of nematodes. The main reasons of this study were as follows: short growth cycle, high hatching rate, simple genetic operation and easy RNA interference of mutants. The nematodes were induced by high concentration glucose diet and fed with common diet. It was found that the increase of fat deposition was an epigenetic phenomenon. 1 mm and 5 mm glucosaccharide were used to induce wild-type N2 nematodes for 2 generations, the second generation was defined as P0, and then the nematodes were fed on ordinary culture medium. It was found that both concentrations of glucosaccharide induced an increase in fat deposition. This increase in fat deposition can be inherited for at least 5 generations, and the nematodes fed on a general diet are called F1F2F3F3F4F5. After 1 mm glucose induction, the increase of fat deposition reached a significant level in all generations compared with the control group. Quantitative PCR was used to detect the expression of 尾 -oxidation-related genes in nematodes from PO to F5 generation, and it was found that the expression of some genes changed significantly. Further, the epigenetic phenomenon of fat deposition was confirmed. Epigenetics is associated with histone methylation and histone acetylation modification. Quantitative PCR was used to detect the key genes related to histone methylation and acetylation respectively, and the expression levels of histone methylation and acetylated modifiers were significantly changed. The change of genetic background of nematode affected the fat deposition of nematodes, and 1 mm glucose was induced in the mutant tph-1. It was found that the increase of fat deposition of the mutant had no epigenetic phenomenon. The results suggest that serotonin signaling pathway may affect the epigenetic of nematode fat deposition. To sum up, the increase of fat deposition induced by. Mm and 5 mm glucose in wild-type N 2 nematode showed epigenetic phenomenon. The fat deposition of nematodes induced by 1 mm glucosaccharide increased significantly in all generations. Therefore, 1 mm glucose induction can achieve the purpose of the experiment. Quantitative PCR detection of 尾-oxidation related genes has also been confirmed. The expression of key genes related to histone modification was detected. It was found that the epigenetic inheritance of nematode fat deposition was affected by histone methylation and acetylation modification. The experiment of tph-1 mutants showed that serotonin signaling pathway may affect the epigenetic of nematode fat deposition.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R589.2;Q78

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