36 research outputs found
Additional file 2: Figure S2. of The MarR-like protein PchR (YvmB) regulates expression of genes involved in pulcherriminic acid biosynthesis and in the initiation of sporulation in Bacillus subtilis
Effect of iron starvation on the expression of cypX and yvmB. The BFA815 (cypX::lacZ) and BSAS108 (pyvmBâ-lacZ) strains were cultivated in LB medium until OD600 of 1. Samples of 2Â ml of the cultures were spread onto solid LB medium containing 20Â ÎŒg.mlâ1 X-gal. A drop of 10Â ÎŒl 10Â mM bipyridyl was deposited at the center of each plate. Blue rings corresponded to expression of the fusion in cells around the inhibition zone of bipyridyl drops. (PDF 75 kb
Contributions maternelles et zygotiques à la reprogrammation des enhancers chez les embryons bovins pré-implantoires
National audienc
Impact dâun environnement diabĂ©tique sur le dĂ©veloppement embryonnaire prĂ©coce
International audienceDiabĂšte et obĂ©sitĂ©, de prĂ©valence croissante, ont un abaissement de lâĂąge de survenue. Les 1ers signes affectent dĂ©sormais les femmes en Ăąge de procrĂ©er. De nombreuses grossesses sont alors affectĂ©es par une hyperglycĂ©mie associĂ©e Ă une hyperinsulinĂ©mie compensatrice en pĂ©riode pĂ©ri-conceptionnelle sans en connaĂźtre les consĂ©quences sur la descendance (1). Des perturbations de lâenvironnement in utero peuvent programmer un risque accru de dĂ©velopper ces mĂȘmes pathologies mĂ©taboliques Ă lâĂąge adulte (2-3). Nous Ă©tudions lâeffet dâune supplĂ©mentation en glucose (15mM) et/ou en insuline (1,7”M) sur le dĂ©veloppement in vitro dâembryon de lapin. Les embryons, collectĂ©s au stade 1 cellule, sont mis en culture jusquâau stade blastocyste, stade composĂ© de deux compartiments, la masse cellulaire interne (individu) et le trophectoderme (placenta). Les transcriptomes ont Ă©tĂ© rĂ©alisĂ©s par RNA-Seq. Un dĂ©veloppement en prĂ©sence de glucose induit un nombre de gĂšne diffĂ©rentiellement exprimĂ© (DEG) plus important dans le trophectoderme que dans la masse cellulaire interne (104vs35), gĂšnes impliquĂ©s dans la prolifĂ©ration, lâapoptose, la diffĂ©renciation et le remodelage de la chromatine. AprĂšs un dĂ©veloppement en prĂ©sence de glucose et dâinsuline, le nombre DEG est plus faible dans le trophectoderme que dans la masse cellulaire interne (15vs104). Les voies dĂ©rĂ©gulĂ©es sont impliquĂ©es dans la prolifĂ©ration, la diffĂ©renciation, la transcription, la phosphorylation oxydative et le stress oxydant. Dans les deux conditions, les embryons prĂ©sentent une augmentation dans la masse cellulaire interne de lâexpression de gĂšnes impliquĂ©s dans la diffĂ©renciation du trophectoderme. Nous montrons quâun dĂ©veloppement de lâembryon en condition (prĂ©)-diabĂ©tique induit une dĂ©rĂ©gulation de voies impliquĂ©es dans le mĂ©tabolisme Ă©nergĂ©tique, la prolifĂ©ration et la diffĂ©renciation avec une altĂ©ration de lâallocation des cellules au placenta, organe clĂ© dans la mĂ©diation de la programmation. La dĂ©rĂ©gulation des gĂšnes impliquĂ©s dans le remodelage de la chromatine suggĂšre un impact au niveau de la rĂ©gulation Ă©pigĂ©nĂ©tique de lâexpression des gĂšnes
Epigenetic programming of the rabbit preimplantation embryo in a diabetic context
International audienc
Epigenetic biomarkers for environmental enrichment and parity in pregnant sows
Session 10. Impact of epigenetics and genetics in determining animal physiologyInternational audienceChanges in the blood cellsâ epigenome, such as variations in DNA methylation, have been proposed as markers of the long-term effects of various factors in humans and in livestock. Therefore, this study aimed to identify pan-genomic DNA methylation variations in association with the well-being of animals submitted to contrasted welfare states. Pregnant sows of mixed parities (low parity (LP) â 2nd and 3rd gestation and high parity (HP) â 4th gestation or higher) were housed in two contrasting conditions throughout gestation (0 to 105 days): in a conventional system on a slatted floor (C: LP, n=9 and HP, n=6) or in an enriched system on accumulated straw with additional space per sow (E: LP, n=6 and HP, n=7). At gestation day 98, pan-genomic DNA methylation from the sowsâ blood mononuclear cells was analysed by reduced representation bisulphite sequencing (RRBS), following the labâs protocol. Only CpGs sites covered by at least 10 uniquely mapped reads (CpG10) were retained and filtered out using a list of 105,171 known Single Nucleotide Polymorphisms (SNPs). Methylation percentages at each CpG10 were calculated and cluster analyses were conducted. Differentially methylated cytosines (DMCs) were identified using methylKit v1.0. (Îmethâ„25% and adjusted P-value <1%) considering the following comparisons: [LPvsHP]C and [LPvsHP]E (parity effect); [CvsE]LP and [CvsE]HP (system effect). Cluster analyses revealed a clear separation corresponding to parity groups. [LPvsHP] displayed more DMC in C (5,391) than in E (3,886) with a similar loss of methylation (53 and 55% in C and E, respectively). Regarding the housing effect, the contrast [CvsE] displayed more DMCs in HP (2,769) than in LP sows (2,183), with an equal number of hypo and hyper DMCs. DMC-targeted genes were mostly associated with cell migration and adhesion, and other immune processes. Taken together, these results suggest that parity has a stronger effect on the immune cellsâ methylome than the housing system
CaractĂ©risation des trajectoires de diffĂ©renciation des cellules germinales au cours de la diffĂ©renciation de l'ovaire fĆtal chez le lapin
International audienc
Programmation Ă©pigĂ©nĂ©tique de lâembryon prĂ©-implantatoire en situation diabĂ©tique : approche multi-omique chez le lapin
International audienceDes perturbations de lâenvironnement pendant des pĂ©riodes clĂ©s du dĂ©veloppement du mammifĂšre affectent le dĂ©veloppement de lâembryon et ont un impact sur le phĂ©notype adulte. Il est actuellement suggĂ©rĂ© une mĂ©diation de ces effets par des mĂ©canismes Ă©pigĂ©nĂ©tiques. Afin dâidentifier les mĂ©canismes impliquĂ©s dans la sensibilitĂ© de lâembryon prĂ©-implantatoire face aux variations mĂ©taboliques de son micro-environnement, nous dĂ©veloppons des approches multi-omiques sur lâembryon de lapin. Dans ce travail, nous nous intĂ©ressons aux consĂ©quences dâun environnement pĂ©ri-conceptionnel riche en glucose et en insuline, caractĂ©ristiques des 1ers signes du diabĂšte dont la prĂ©valence chez des femmes de plus en plus jeunes est accrue. Nous Ă©mettons lâhypothĂšse quâun environnement hyperglycĂ©mique/hyperinsulinĂ©mique dans les 1ers jours de dĂ©veloppement dĂ©rĂ©gule les mĂ©canismes Ă©pigĂ©nĂ©tiques conduisant Ă une programmation Ă long terme. Pour tester cette hypothĂšse, nous dĂ©terminons l'impact d'une supplĂ©mentation en glucose et/ou en insuline sur le transcriptome et lâĂ©pigĂ©nome de lâembryon de lapin dĂ©veloppĂ© in vitro. Les transcriptomes de la masse cellulaire interne (futur individu) et du trophectoderme (futur placenta) ont Ă©tĂ© obtenus par RNA-Seq. Les toutes 1Ăšres analyses montrent une sensibilitĂ© plus importante du trophectoderme face Ă une culture en prĂ©sence de glucose et/ou dâinsuline, comparativement Ă la masse cellulaire interne. Dans le trophectoderme, le glucose dĂ©rĂ©gule lâexpression de gĂšnes impliquĂ©s dans le cycle cellulaire, la phosphorylation oxydative mais Ă©galement dans la mĂ©thylation des histones. Ces altĂ©rations sont moindres lors dâune culture en prĂ©sence de glucose et dâinsuline. Une analyse approfondie des gĂšnes candidats est en cours. Nous dĂ©terminerons ensuite le mĂ©thylome de la masse cellulaire interne et du trophectoderme de ces embryons par RRBS (Reduced Representation Bisulfite Sequencing). Le profil de mĂ©thylation des CpG sera analysĂ© afin de dĂ©terminer les rĂ©gions diffĂ©rentiellement mĂ©thylĂ©s (DMR) dont l'emplacement permettra d'identifier les gĂšnes candidats. Afin de dĂ©terminer le lien entre altĂ©ration de lâexpression des gĂšnes et modifications Ă©pigĂ©nĂ©tiques, nous intĂšgrerons les donnĂ©es de transcriptome et de mĂ©thylome. Selon les rĂ©sultats obtenus, nous effectuerons un profilage mĂ©tabolomique par 1H RMN des milieux de culture ayant contenu les embryons. Nous envisageons Ă©galement de dĂ©terminer les profils mĂ©tabolomiques de la masse cellulaire interne et du trophectoderme. LâĂ©tablissement dâun spectre RMN sur petite quantitĂ© de matĂ©riel est en cours de mise au point (CI-EndoMetaBryo-2019). LâintĂ©gration de ces donnĂ©es omiques nous permettra dâidentifier les voies altĂ©rĂ©es par le glucose et lâinsuline au sein des deux compartiments embryonnaires
Single-cell RNA Transcriptome Atlas of the Developing Fetal Rabbit Ovary
International audienceIn mammals, the formation of the ovary begins early during fetal development by the differentiation of gonadal supporting cells into ovarian pre-granulosa cells. Subsequently, female germ cells differentiate and acquire the ability to enter meiosis. Meiosis initiation is a crucial step for the production of functional haploid gametes. The onset of meiosis is driven by interactions between somatic cells and germ cells and it is controlled by a strict transcriptomic program. While this process occurs almost synchronically in the mouse ovary, germ cells enter meiosis between 24- and 28-days post-conception (7 to 3 days before birth) and coexist with proliferating germ cells in the rabbit ovary. The asynchrony of the transition from mitosis to meiosis results in heterogeneity in the female ovarian cell populations, which make difficult the study of the mechanisms involved in meiosis initiation and progression. To further understand the process of ovarian differentiation at the level of the individual cell populations, we used the 10X Genomics single-cell RNA-seq technology (scRNA-seq) and analyzed the transcriptional profiles of two independent replicates of 8 000 single ovarian cells collected from 24 and 28-days dpc rabbit fetal ovaries. Hierarchical clustering analysis of our data set revealed 14 distinct clusters at both stage. To classify each cell population, we analyzed the transcriptional profiles of established cell typeâspecific markers. Among them, we listed WNT6 and LGR5 as pre-granulosa cells markers, CYP17A1 as steroidogenic cells marker, NR2F2 as mesenchymal cells marker, DDX4 and POU5F1 as germ cells markers, STRA8 and REC8 as early meiotic germ cells markers and SPO11 and SYCP3 as late meiotic germ cell markers. These findings provide the first global view of cellular differentiation in a window of time which correspond to the onset of meiosis in the rabbit ovary
The Transcription Factor DMRT1 Regulates Germ Cell Differentiation and Meiosis in the Rabbit Fetal Ovary
International audienc