Comparative study of the digestion and metabolism related genes' expression changes during the postnatal food change in different dietary mammals

Impact of DNA methylation on digestive and metabolic gene expression in red pandas (Ailurus fulgens) during the transition from milk to bamboo diet

BACKGROUND

DNA methylation plays a crucial role in species development and environmental adaptation. In mammals, there are significant dietary changes from infancy to adulthood. Notably, the red panda transitions from milk consumption as juveniles to a bamboo-based diet as adults, with significant alterations in food characteristics and nutritional content. However, the regulatory role of DNA methylation in this process remains unclear. In this study, we investigate the regulatory role of DNA methylation on the expression of digestive and metabolic genes in the liver and pancreas during the red panda's dietary transition from suckling stage to adulthood.

RESULTS

Our findings reveal significant differences in DNA methylation patterns before and after dietary transition, highlighting the specific alterations in the methylation profiles of genes involved in lipid, carbohydrate, and amino acid metabolism. We found that perilipin-4 (PLIN4) is hypomethylated and highly expressed in the liver of adult red pandas, facilitating lipid droplet formation and storage, crucial for adapting to the low-fat content in bamboo. In contrast, genes like lipoprotein lipase (LPL), crucial for lipid breakdown, exhibited hypermethylated with low-expression patterns, reflecting a reduced lipid metabolism capacity in adults. Carbohydrate metabolism-related genes like ADH4 and FAM3C are hypomethylated and highly expressed in adults, enhancing glycogen production and glucose utilization. Genes involved in protein metabolism like CTSZ and GLDC, exhibit hypomethylated with high-expression and hypermethylated with low-expression patterns in the pancreas of adults, respectively, contributing to protein metabolism balance post-weaning.

CONCLUSION

This study reveals the regulatory role of DNA methylation in the dietary transition of red pandas from milk to bamboo and provides methylation evidence for the molecular regulation of adaptive expression of digestive and metabolic genes in red pandas with specialized diets.

Dietary type (carnivore, herbivore and omnivore) and animal species modulate the nutritional metabolome of terrestrial species

Ecometabolomics could be implemented as a powerful tool in molecular ecology studies, but it is necessary to know the baseline of certain metabolites and understand how different traits could affect the metabolome of the animals. Therefore, the main objective of this study was to provide values for the nutritional metabolome profile of different diet groups and animal species, as well as to study the differences in the metabolomic profile due to the effect of diet type and species. To achieve this goal, blood samples were taken from healthy animals (n = 43) of different species: lion (Panthera leo), jaguar (Panthera onca), chimpanzee (Pan troglodytes), bison (Bison bison), gazelle (Gazella cuvieri) and fallow deer (Dama dama), and with different types of diet (carnivore, herbivore and omnivore). Each blood sample was analysed to determine nutritional metabolites. The main results this study provides are the nutritional metabolic profile of these animals based on the type of diet and the animal species. A significant effect of the dietary type was found on nutritional metabolite levels, with those metabolites related to protein metabolism (total protein and creatine) being higher in carnivores. There is also an effect of the species on nutritional metabolites, observing a metabolome differentiation between lion and jaguar. In the case of herbivores, bison showed higher levels of uric acid and cholesterol, and lower urea levels than gazelle and fallow deer. More molecular ecology studies are needed to further the knowledge of the metabolism of these animals.