Lipid rafts are operationally defined as cholesterol-rich membrane microdomains resistant to solubilization in nonionic detergents at low temperatures. Lipid rafts, which are quite different in lipid composition from the surrounding membranes, are of great importance to signal transduction, protein sorting and membrane transport. They have been implicated in a range of biosynthetic and endocytic processes and systems-signaling, molecular trafficking, diseases as well as being involved in the immune, vascular, digestive and reproductive systems. Dietary nutrients like fatty acids and vitamins of different types also play a critical and decisive role in the regulation of lipid rafts. / text

Previously, the exact phylogenetic relationship between the giant panda (Ailuropoda melanoleuca) and the red panda (Ailurus fulgens) has been unclear, but with the advent of molecular sequencing technologies, these two animals are now known to be distantly related. Although taxonomically distinct, these two panda species have several things in common, primarily their almost exclusively bamboo diet, but also their similar physical adaptations to their diet and their sympatry in some locations. What was unknown was if their similarities also extended to their gastrointestinal tract (GIT) microbiota. Using next-generation 16S rRNA parallel sequencing technologies, we uncovered several factors that impact bacterial communities of the pandas and also found that the two panda species harbor distinct microbial communities. In general, the Firmicutes and the Proteobacteria dominate both pandas’ gut microbiomes, with lesser contributions by the Actinobacteria and the Bacteroidetes. However, for the red panda, sex, age, and season significantly alter GIT microbiota. For giant pandas, we found that bacterial communities differed significantly between their normal fecal samples and mucus excretions. Together, these data display the plasticity of their bacterial communities, with several factors shaping GIT microbiota. As both species are highly threatened, understanding the relationship between the panda and their gut microbiome has given insight into the overall health of these uniquely herbivorous carnivores.