Project description:Our findings help us gain new insight into the immunological reactions induced by transplantation in pearl mussels and markedly bring us more clues about pearl sac formation, contributing to the novel development of management strategies for pearl culture.
Project description:The freshwater pearl mussel Margaritifera margaritifera is one of the most threatened freshwater bivalves worldwide. In this study, we aimed (i) to study the processes by which water quality might affect freshwater mussels in situ and (ii) to provide insights into the ecotoxicological significance of water pollution to natural populations in order to provide necessary information to enhance conservation strategies. M. margaritifera specimens were sampled in two close sites located upstream or downstream from an illegal dumping site. The renal transcriptome of these animals was assembled and gene transcription determined by RNA-seq. Correlations between transcription levels of each single transcript and the bioaccumulation of 9 trace metals, age (estimated by sclerochronology) and condition index were determined in order to identify genes likely to respond to a specific factor. Amongst the studied metals, Cr, Zn, Cd and Ni were the main factors correlated with transcription levels, with effects on translation, apoptosis, immune response, response to stimulus and transport pathways. However, the main factor explaining changes in gene transcription appeared to be the age of individuals with a negative correlation with the transcription of retrotransposons-related genes. To investigate this effect further, mussels were classified into 3 age classes. In young, middle-aged and old animals, transcription levels were mainly explained by Cu, Zn and age, respectively. This suggests differences in the molecular responses of this species to metals during its lifetime that must be better assessed in future ecotoxicology studies.
Project description:The nacre color of shells has an effect on the pearl color in Hyriopsis cumingii, and is an important indicator for its value. However, little exosome and micro (mi)RNA information are available on nacre color formation in mussels. In this study, exosomes of mantles were extracted from white and purple mussels. High-throughput Illumina sequencing was performed on the white and purple mussel mantle exosomes.Moreover, miR-223 negatively regulated hcApo, which plays important roles in the absorption and transport of β-carotene in H. cumingii. These results improve our understanding of the molecular mechanisms of nacre color formation in H. cumingii.
Project description:Clostridium perfringens type A is a common source of food poisoning in humans. Vegetative cells sporulate in the small intestinal tract and produce a major pathogenic factor, C. perfringens enterotoxin (CPE) during sporulation. Although sporulation plays a critical role in the pathogenesis of food poisoning, the mechanisms to induce in vivo sporulation remain unclear. Bile salts had been identified to mediate sporulation, and we have confirmed deoxycholate (DCA)-induced sporulation in C. perfringens strain NCTC8239 co-cultured with human intestinal epithelial Caco-2 cells. In this study, we performed global transcriptome analysis of strain NCTC8239 to elucidate the mechanism to induce sporulation by DCA.
Project description:Experimental IgE-mediated food allergy depends on intestinal anaphylaxis driven by interleukin (IL)-9. However, the primary cellular source of IL-9 and the mechanisms underlying the susceptibility to food-induced intestinal anaphylaxis remain unclear. Herein, we have reported the identification of multifunctional IL-9-producing mucosal mast cells (MMC9s) that can secrete prodigious amounts of IL-9 and IL-13 in response to IL-33, and mast cell protease-1 (MCPt-1) in response to antigen and IgE complex crosslinking, respectively. Repeated intragastric antigen challenge induced MMC9 development that required T cells, IL-4, and STAT6 transcription factor, but not IL-9 signals. Mice ablated of MMC9 induction failed to develop intestinal mastocytosis, which resulted in decreased food allergy symptoms that could be restored by adoptively transferred MMC9s. Finally, atopic patients that developed food allergy displayed increased intestinal expression of Il9 and MC-specific transcripts. Thus, the induction of MMC9s is a pivotal step to acquire the susceptibility to IgE-mediated food allergy.
Project description:Mammals have evolved sex-specific adaptations to reduce energy usage in times of food scarcity. These adaptations are well described for peripheral tissue, though much less is known about how the energy-expensive brain adapts to food restriction, and how such adaptations differ across the sexes. Here, we examined how food restriction impacts energy usage and function in the primary visual cortex (V1) of adult male and female mice. Molecular analysis and RNA sequencing revealed that food restriction modulated canonical, energy-regulating pathways including oxidative phosphorylation, AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) signalling, significantly in males but not in females V1. Moreover, we found that in contrast to males, food restriction in females non-significantly affected V1 ATP usage and visual coding precision (assessed by orientation selectivity). Decreased serum leptin is necessary for triggering energy-saving changes in male mouse V1 during food restriction. Consistent with this result, we found a significant decrease of serum leptin in food-restricted males but no significant change in food-restricted females. Collectively, our findings demonstrate that cortical function and energy usage in female mice are more resilient to food restriction than in males. The neocortex, therefore, contributes to sex-specific, energy-saving adaptations in response to metabolic challenge.