Project description:In rodents, brown adipose tissue (BAT) contributes to whole body energy expenditure and low BAT activity is related to hepatic fat accumulation, partially attributable to the gut microbiome. Little is known of these relationships in humans. In adults (n=60), we assessed hepatic fat and cold-stimulated BAT activity utilizing magnetic resonance imaging and the gut microbiome with 16S sequencing. We transplanted gnotobiotic mice with feces from humans to assess the transferability of BAT activity and NAFLD through the microbiome. Individuals with NAFLD (n=29) had lower BAT activity than those without and BAT activity was inversely related to hepatic fat. Although the fecal microbiome was different in those with NAFLD, no differences were observed in relation to BAT activity and neither of these phenotypic traits were transmissible through fecal transplant to gnotobiotic mice. Thus, low BAT activity is associated with hepatic steatosis but this is not mediated through the gut microbiota.
Project description:Background: Through the evolution of novel wing structures, bats (Order Chiroptera) became the only mammalian group to achieve powered flight. This achievement preceded the massive adaptive radiation of bats into diverse ecological niches. We investigate here some of the developmental processes that underlie the origin and subsequent diversification of one of the novel membranes of the bat wing: the plagiopatagium, which connects the fore- and hind limb in all bat species. Results: Our results suggest that the plagiopatagium initially arises through novel outgrowths from the body flank that subsequently merge to the limbs to generate the wing airfoil. Our findings further suggest that this merging process, which is highly conserved across bats, occurs through modulation of the programs controlling the development of the periderm of the epidermal epithelium. Finally, our results suggest that the shape of the plagiopatagium begins to diversify in bats only after this merging has occurred. Conclusions: This study demonstrates how a focus on the evolution of cellular processes can inform an understanding of the developmental factors shaping evolution of novel, highly adaptive structures.
Project description:Induced pluripotent stem cells (iPSCs) are capable of providing an unlimited source of cells from all three germ layers as well as germ cells. The derivation and usage of iPSCs from various animal models may facilitate stem-cell-based therapy, generation of gene-modified animals, and evolutionary studies assessing interspecies differences. However, there is a lack of species-wide methods for deriving iPSCs, in particular by means of non-viral and non-transgene-integrating (NTI) approaches. Here, we demonstrated the derivation of iPSCs from somatic fibroblasts of multiple mammalian species from three different taxonomic orders, including the common marmoset (Callithrix jacchus) in Primates, the dog (Canis lupus familiaris) in Carnivora, and the pig (Sus scrofa) in Cetartiodactyla, by combinatorial usage of chemical compounds and NTI episomal vectors. Interestingly, the somatic fibroblasts temporarily acquired a neural stem cell (NSC)-like state during the reprogramming procedure. Collectively, our method, robustly applicable to various species, holds a great potential for facilitating stem-cell-based research using various animals in Mammalia.
Project description:Induced pluripotent stem cells (iPSCs) are capable of providing an unlimited source of cells from all three germ layers as well as germ cells. The derivation and usage of iPSCs from various animal models may facilitate stem-cell-based therapy, generation of gene-modified animals, and evolutionary studies assessing interspecies differences. However, there is a lack of species-wide methods for deriving iPSCs, in particular by means of non-viral and non-transgene-integrating (NTI) approaches. Here, we demonstrated the derivation of iPSCs from somatic fibroblasts of multiple mammalian species from three different taxonomic orders, including the common marmoset (Callithrix jacchus) in Primates, the dog (Canis lupus familiaris) in Carnivora, and the pig (Sus scrofa) in Cetartiodactyla, by combinatorial usage of chemical compounds and NTI episomal vectors. Interestingly, the somatic fibroblasts temporarily acquired a neural stem cell (NSC)-like state during the reprogramming procedure. Collectively, our method, robustly applicable to various species, holds a great potential for facilitating stem-cell-based research using various animals in Mammalia.