The circadian clock influences nearly all aspects of physiology and behavior, including sleep-wake cycles, the endocrine system, and hepatic metabolism. Glucose and lipid metabolism also exist circadian rhythms in the liver and these processes are regulated by the circadian clock. Methionine (Met) is closely related to lipid metabolism, including de novo lipogenesis, steatolysis and fatty acid oxidation.

Researchers from the Institute of Subtropical Agriculture (ISA) of the Chinese Academy of Sciences conducted a 70-day experiment to explore the effects on serum biochemistry, mRNA expression of circadian clock- and glucose and lipid metabolism-related genes in the liver of laying hens (Brown Hyline, 180 birds, 41-weeks).

These hens are under the circadian feeding regimes with low Met (0.27%) diets and high Met (0.33%) diets in daily cycles.

Researchers found that the serum alkaline phosphatase activity in the High-Low (HL) group was the highest at Zeitgeber time(ZT)9.5 and ZT13.5 and that the serum glucose content in the HL group was lowest at ZT21.5 compared to the other 2 groups (P < 0.05). The mesors, amplitudes and acrophases of the cosine curves for the CLOCK, BMAL1, CRY1, PER2, and PER3 genes were altered in the low-high(LH) and HL groups.

Different feeding regimes significantly affected the expression of FASN, GPAT, HMGCR, LDLR, ACACA, SREBP1, and INSIG1 (P < 0.05). It is concluded that dynamical feeding low and high methionine diets affected the variation of serum alkaline phosphatase and glucose levels, as well as the mRNA expression of circadian clock- and glucose and lipid metabolism- related genes in the liver of laying hens.

Their pervious results showed that dynamic feeding of low and high Met diets altered the circadian variation of serum total cholesterol and triglycerides levels, as well as the yolk ratio in the eggs.

 Dynamic feeding low and high methionine diets may affect energy metabolism not only directly, but also through the circadian clock.

The study entitled “Effects of dynamic feeding low and high methionine on the variation of glucose and lipid metabolism-related genes in the liver of laying hens” was published in Poultry Science, details can be found at https://academic.oup.com/ps/article-abstract/98/5/2231/5281186.

It was supported by the National Key Research and Development Program of China.

Contact: WU Xin

E-mail: wuxin@isa.ac.cn

Institute of Subtropical Agriculture, Chinese Academy of Sciences