Project description:This study aimed at providing insights into the hypothesized functional link between olfactory sensing of the spawning ground and final sexual maturation. We have therefore assessed the presence and expression levels of olfactory genes by RNA sequencing (RNAseq) of the olfactory rosettes in homing chum salmon Oncorhynchus keta Walbaum from the coastal sea to 75 km upstream the rivers at the pre-spawning ground. RNAseq revealed the expression of 75 known and 27 unknown salmonid olfactory genes of which 13 genes were differentially expressed between fish from the pre-spawning area and from the coastal area, suggesting an important role of these genes in homing. Olfactomedins and ependymin are candidates among the differentially expressed genes that may connect olfactory reception to the expression of sgnrh to regulate final maturation. Deep-sequencing transcriptome analysis of twelve chum salmon olfactory rosette RNA samples: three females and three males from the pre-spawning area and three females and three males from the coastal area.
Project description:Histone acetylation and deposition of H2A.Z variant are integral aspects of active transcription. In Drosophila, the single DOMINO chromatin regulator complex is thought to combine both activities via an unknown mechanism. Here we show that two alternative splice isoforms of the DOMINO nucleosome remodeling ATPase, DOM-A and DOM-B, directly specify two distinct multi-subunit complexes. Both complexes are necessary for transcriptional regulation but through different mechanisms. The DOM-B complex incorporates H2A.V (the fly ortholog of H2A.Z) genome-wide in an ATP-dependent manner, like the yeast SWR1 complex. The DOM-A complex, instead, functions as an ATP-independent histone acetyltransferase complex similar to the yeast NuA4, targeting lysine 12 of histone H4. Our work provides an instructive example of how different evolutionary strategies lead to similar functional separation.
Project description:Non-targeted LC-MS/MS analysis of PPL solid phase extracted dissolved organic matter (DOM) from TARA/TREC Expedition Leg 1, collected in the coastal Atlantic between France to Netherlands in Spring 2023.
Project description:This study aimed at providing insights into the hypothesized functional link between olfactory sensing of the spawning ground and final sexual maturation. We have therefore assessed the presence and expression levels of olfactory genes by RNA sequencing (RNAseq) of the olfactory rosettes in homing chum salmon Oncorhynchus keta Walbaum from the coastal sea to 75 km upstream the rivers at the pre-spawning ground. RNAseq revealed the expression of 75 known and 27 unknown salmonid olfactory genes of which 13 genes were differentially expressed between fish from the pre-spawning area and from the coastal area, suggesting an important role of these genes in homing. Olfactomedins and ependymin are candidates among the differentially expressed genes that may connect olfactory reception to the expression of sgnrh to regulate final maturation.
Project description:Histone acetylation and deposition of H2A.Z variant are integral aspects of active transcription. In Drosophila, the single DOMINO chromatin regulator complex is thought to combine both activities via an unknown mechanism. Here we show that two alternative splice isoforms of the DOMINO nucleosome remodeling ATPase, DOM-A and DOM-B, directly specify two distinct multi-subunit complexes. Both complexes are necessary for transcriptional regulation but through different mechanisms. The DOM-B complex incorporates H2A.V (the fly ortholog of H2A.Z) genome-wide in an ATP-dependent manner, like the yeast SWR1 complex. The DOM-A complex, instead, functions as an ATP-independent histone acetyltransferase complex similar to the yeast NuA4, targeting lysine 12 of histone H4. Our work provides an instructive example of how different evolutionary strategies lead to similar functional separation.
Project description:Histone acetylation and deposition of H2A.Z variant are integral aspects of active transcrip-tion. In Drosophila, the single DOMINO chromatin regulator complex is thought to combine both activities via an unknown mechanism. Here we show that alternative isoforms of the DOMINO nucleosome remodeling ATPase, DOM-A and DOM-B, directly specify two distinct multi-subunit complexes. Both complexes are necessary for transcriptional regulation but through different mechanisms. The DOM-B complex incorporates H2A.V (the fly ortholog of H2A.Z) genome-wide in an ATP-dependent manner, like the yeast SWR1 complex. The DOM-A complex, instead, functions as an ATP-independent histone acetyltransferase com-plex similar to the yeast NuA4, targeting lysine 12 of histone H4. Our work provides an in-structive example of how different evolutionary strategies lead to similar functional separation. In yeast and humans, nucleosome remodeling and histone acetyltransferase complexes orig-inate from gene duplication and paralog specification. Drosophila generates the same diversi-ty by alternative splicing of a single gene.
Project description:Diazotrophs provide the main source of reactive nitrogen to the ocean, sustaining primary productivity and CO2 uptake. Climate change is raising temperatures, decreasing pH and reducing nutrient availability. How microbes respond to these changes is largely unexplained. Similarly, the role of DOM in the growth and survival of certain diazotrophic organisms is poorly understood. Moreover, growing evidence indicates some diazotrophs are capable of utilizing distinct DOM compounds via osmotrophy providing them with additional metabolic plasticity and ecological advantages compared to other non-diazotrophic microbes. We aimed to understand how osmotrophy could modify carbon uptake and alleviate energy stress in diazotrophs under ongoing climate change perturbations. We hypothesized that Crocosphaera preferentially uses DOM when labile as a carbon source in present pH conditions, as compared to future more acidic scenarios with higher access to inorganic carbon. Alternatively, the lower pH may cause Crocosphaera to be energy limited when trying to maintain intracellular homeostasis which would favour DOM uptake as an extra source of energy.
Project description:Deoxynivalenol (DON) is a frequent mycotoxin in grains, produced by Fusarium fungi, which demonstre multiple side effects such as modulation of immune responses, reduced feed intake and weight gain or impairment of the intestinal barrier function. Among animal species, pigs are the best model for humans and are very sensitive to DON. In wheat, DON can be conjugated to glucose to form DON-3-β-D-glucoside (D3G). Some bacteria isolated from digestive tracts or soil, are also able to de-epoxydize or epimerize DON to metabolites such as deepoxy-deoxynivalenol (DOM-1) or 3-epi-deoxynivalenol (epi-DON). The toxicity of these DON metabolites is poorly documented. By the way of ingestion, the intestine is the first organ exposed to these molecules and so constitute a relevant model. The aim of this study was to compare the intestinal toxicity of three DON metabolites (D3G, DOM-1 and epi-DON) with the one of DON. Intestinal explants from 6 pigs were treated with 10mM DON, D3G, DOM-1 or epi-DON for 4 hours and transcriptomic analysis was performed using an âAgilent Porcinet 60Kâ. Jejunal explants from 4 piglets aged of 5 weeks were sampled and exposed in vitro to differents molecules (DON, D3G, DOM-1 & 3-epi-DON) at 10µM during 4h. Then RNA was extracted.