Transgenerational effect of cold challenge

Abstract

It has long been observed that certain phenotypic alterations caused by environment would be transferred to the next generation. However, the phenomenon was hard to be explained by the Mendelian theory. Since last century, there have been advancement in Epigenetics research, which provides alternative explanations to the transgenerational effect of the environmental modification on the organism. Variation of temperature happens all the time and it is known that the cold challenge would modify the hormone levels and adipose tissue biology in the body. However, whether and how cold challenge will have transgenerational influence is unknown. Therefore, in the current study, we aim to examine the transgenerational effect conferred by cold challenge. To this end, the mice (F0) were subjected to intermittent mild cold challenge for one month and the metabolic phenotypes in their offsprings (F1) were monitored and compared with those born from the control mice. We found that the long-term cold challenge changes on the parents not only changes the body mass, but also the nutritious and energy metabolism, especially during the early stage of high fat diet feeding and upon an acute cold challenge on the offsprings. Compared to the F1 mice from parents housed at room temperature, the F1 mice, whose fathers were stimulated with cold temperature, gained more weight and were more insulin resistant upon high fat diet feeding; In addition, when F1 mice were exposed to short term cold challenge, the significant difference on their thermogenesis level in adipose tissues was also detected between sons of cold challenge mice and sons of room temperature mice. The DNA methylation level in adipose tissue was significantly elevated in F1 mice from cold challenged mice. Therefore, in this study, we found that cold challenge impacts the metabolic behaviors in their offsprings. Moreover, the phenotypic changes were accompanied by changes in DNA methylation on the next generation. It indicated that there was transgenerational cold challenge effect which was mediated in an epigenetic mechanism. The detailed changes on DNA methylation and whether the changes on metabolic traits would de inherited to the third generation (F2) are under investigation.