小鼠实验 z-bo 2020-12-17 332

　　Researchers have discovered that the health effects of a poor diet can be passed on to offspring through eggs and sperm cells without DNA mutations. A mouse study published a few days ago in the journal Nature Genetics provides some of the strongest evidence so far for the non-gene inheritance of acquired characteristics in organisms. Moreover, although previous studies have shown that sperm cells can carry epigenetic factors, this is the first time such effects have been observed in egg cells.

　　 Scientists have long suspected that parents’ lifestyle and behavior choices will affect children’s health through epigenetics. The chemical modification of DNA or chromosome proteins can affect how genes are expressed, but they will not change the sequence of genes. Therefore, whether these changes can be inherited remains controversial.

　　 In the latest study, Peter Huypens, an endocrinologist at the German Environmental Health Research Center, and his colleagues fed mice with the same genes one of three foods-high-fat, low-fat or standard laboratory foods-for 6 weeks. Unsurprisingly, the mice that ate high-fat food began to gain weight and impaired glucose tolerance, which is an early symptom of type 2 diabetes.

　　 Subsequently, the team removed eggs and sperm cells from the three groups of mice, performed in vitro fertilization, and transplanted the obtained embryos into healthy "surrogate" mothers. Their idea is that if a physical characteristic or behavior can be observed in offspring, it can only be passed on through egg or sperm cells.

　　 When the offspring of adult mice are subsequently fed a high-fat diet, those with obese parents seem to be more likely to gain weight and develop glucose intolerance, especially if both parents are obese. The offspring with thinner parents gained the least weight.

　　 Surprisingly, the authors of the paper report the difference between male and female offspring: If the parents are obese, daughters seem to gain weight more easily, while sons often only suffer from glucose intolerance. Compared with the father, the mother's diet seems to have a greater impact on the offspring's metabolism. Huypens said that this is very interesting, because similar patterns have also appeared in some human epidemiological studies.