Project description:During the nest-founding phase of the bumble bee colony cycle, queens undergo striking changes in maternal care behavior. Early in the founding phase, prior to the emergence of workers in the nest, queens are reproductive and also provision and feed their offspring. However, later in the founding phase, queens cease feeding offspring and become specialized on reproduction. This transition is synchronized with the emergence of workers in the colony, who assume the task of feeding their siblings. Using a social manipulation experiment, we tested the hypothesis that workers socially regulate the transition from feeding brood to specialization on reproduction in nest-founding bumble bee queens. Consistent with this hypothesis, we found that early-stage queens with workers prematurely added to their nests reduce their brood-feeding behavior and increase egg-laying, and likewise, late-stage queens increase their brood-feeding behavior and decrease egg-laying when workers are removed from their nests. Further, brood-feeding and egg-laying behavior were negatively correlated in these queens. We used an Agilent brain EST-based microarray to explore a second hypothesis, that workers alter brain gene expression in nest-founding queens. We found evidence that brain gene expression in nest-founding queens is altered by the presence of workers, with the effect much stronger in late-stage founding queens. Additionally, expression levels of some genes were correlated with quantitative differences in brood-feeding and egg-laying behavior. This study provides new insights into how the transition from feeding brood to specialization on reproduction in bumble bee queens is regulated during the nest initiation phase of the colony cycle.
Project description:Pancreatic cancer is the 3rd most prevalent cause of cancer related deaths in United states alone, with over 55000 patients being diagnosed in 2019 alone and nearly as many succumbing to it. Late detection, lack of effective therapy and poor understanding of pancreatic cancer systemically contributes to its poor survival statistics. Obesity and high caloric intake linked co-morbidities like type 2 diabetes (T2D) have been attributed as being risk factors for a number of cancers including pancreatic cancer. Studies on gut microbiome has shown that lifestyle factors as well as diet has a huge effect on the microbial flora of the gut. Further, modulation of gut microbiome has been seen to contribute to effects of intensive insulin therapy in mice on high fat diet. In another study, abnormal gut microbiota was reported to contribute to development of diabetes in Db/Db mice. Recent studies indicate that microbiome and microbial dysbiosis plays a role in not only the onset of disease but also in its outcome. In colorectal cancer, Fusobacterium has been reported to promote therapy resistance. Certain intra-tumoral bacteria have also been shown to elicit chemo-resistance by metabolizing anti-cancerous agents. In pancreatic cancer, studies on altered gut microbiome have been relatively recent. Microbial dysbiosis has been observed to be associated with pancreatic tumor progression. Modulation of microbiome has been shown to affect response to anti-PD1 therapy in this disease as well. However, most of the studies in pancreatic cancer and microbiome have remained focused om immune modulation. In the current study, we observed that in a T2D mouse model, the microbiome changed significantly as the hyperglycemia developed in these animals. Our results further showed that, tumors implanted in the T2D mice responded poorly to Gemcitabine/Paclitaxel (Gem/Pac) standard of care compared to those in the control group. A metabolomic reconstruction of the WGS of the gut microbiota further revealed that an enrichment of bacterial population involved in drug metabolism in the T2D group.
Project description:In social insects, workers perform distinct tasks according to the caste they belong to, and workers from different castes differ in their age (nest workers are usually younger than foragers are). The caste shift thus seems inseparable from age, preventing from deciphering the role of labour division and age in regulating individual physiology and ageing rates. We set up an experimental protocol separating age and caste effects by defining four groups of black garden ant (Lasius niger) workers: young foragers (Y.F), old foragers (O.F), young nest workers (Y.NW) and old nest workers (O.NW). Proteomics highlighted differences between individuals according to their age, whereas metabolomics revealed caste-related differences. Our study highlighted that age and caste influence specifically different aspects of the physiology of ant workers.
Project description:Aging is associated with declining immunity and inflammation as well as alterations in the gut microbiome with a decrease of beneficial microbes and increase in pathogenic ones. The aim of this study was to investigate aging associated gut microbiome in relation to immunologic and metabolic profile in a non-human primate (NHP) model. 12 old (age>18 years) and 4 young (age 3-6 years) Rhesus macaques were included in this study. Immune cell subsets were characterized in PBMC by flow cytometry and plasma cytokines levels were determined by bead based multiplex cytokine analysis. Stool samples were collected by ileal loop and investigated for microbiome analysis by shotgun metagenomics. Serum, gut microbial lysate and microbe-free fecal extract were subjected to metabolomic analysis by mass-spectrometry. Our results showed that the old animals exhibited higher inflammatory biomarkers in plasma and lower CD4 T cells with altered distribution of naïve and memory T cell maturation subsets. The gut microbiome in old animals had higher abundance of Archaeal and Proteobacterial species and lower Firmicutes than the young. Significant enrichment of metabolites that contribute to inflammatory and cytotoxic pathways was observed in serum and feces of old animals compared to the young. We conclude that aging NHP undergo immunosenescence and age associated alterations in the gut microbiome that has a distinct metabolic profile.