Project description:Bioinformatic prediction, deep sequencing of microRNA and expression analysis during phenotypic plasticity in the pea aphid acyrthosiphon pisum We developed high throughput Solexa sequencing and bioinformatic analyses of the genome of the pea aphid Acyrthosiphon pisum in order to identify the first miRNAs from a hemipteran insect. By combining these methods we identified 155 miRNAs including 56 conserved and 99 new miRNAs. Moreover, we investigated the regulation of these miRNAs in different alternative morphs of the pea aphid by analysing the expression of miRNAs across the switch of reproduction mode.
Project description:In the present study, genomic binding sites of glucocorticoid receptors (GR) were identified in vivo in the rat hippocampus applying chromatin immunoprecipitation followed by next-generation sequencing. We identified 2470 significant GR-binding sites (GBS) and were able to confirm GR binding to a random selection of these GBS covering a wide range of P values. Analysis of the genomic distribution of the significant GBS revealed a high prevalence of intragenic GBS. Gene ontology clusters involved in neuronal plasticity and other essential neuronal processes were overrepresented among the genes harboring a GBS or located in the vicinity of a GBS. Male adrenalectomized rats were challenged with increasing doses of the GR agonist corticosterone (CORT) ranging from 3 to 3000 μg/kg, resulting in clear differences in the GR-binding profile to individual GBS. Two groups of GBS could be distinguished: a low-CORT group that displayed GR binding across the full range of CORT concentrations, and a second high-CORT group that displayed significant GR binding only after administering the highest concentration of CORT. All validated GBS, in both the low-CORT and high-CORT groups, displayed mineralocorticoid receptor binding, which remained relatively constant from 30 μg/kg CORT upward. Motif analysis revealed that almost all GBS contained a glucocorticoid response element resembling the consensus motif in literature. In addition, motifs corresponding with new potential GR-interacting proteins were identified, such as zinc finger and BTB domain containing 3 (Zbtb3) and CUP (CG11181 gene product from transcript CG11181-RB), which may be involved in GR-dependent transactivation and transrepression, respectively. In conclusion, our results highlight the existence of 2 populations of GBS in the rat hippocampal genome. - See more at: http://press.endocrine.org/doi/10.1210/en.2012-2187?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dpubmed#sthash.LqK088DP.dpuf
Project description:Group B Streptococcus (GBS) is a pervasive perinatal pathogen, yet factors driving GBS dissemination in utero are poorly defined. Gestational diabetes mellitus (GDM), a complication marked by dysregulated immunity and maternal microbial dysbiosis, increases risk for GBS perinatal disease. We interrogated host-pathogen dynamics in a novel murine GDM model of GBS colonization and perinatal transmission. GDM mice had greater GBS in utero dissemination and subsequently worse neonatal outcomes. Dual-RNA sequencing revealed differential GBS adaptation to the GDM reproductive tract, including a putative glycosyltransferase (yfhO), and altered host responses. GDM disruption of immunity included reduced uterine natural killer cell activation, impaired recruitment to placentae, and altered vaginal cytokines. Lastly, we observed distinct vaginal microbial taxa associated with GDM status and GBS invasive disease status. Our translational model of GBS perinatal transmission in GDM hosts recapitulates several clinical aspects and enables discovery of host and bacterial drivers of GBS perinatal disease.
Project description:Saprobic microorganisms, such as filamentous fungi of the genus Aspergillus, are of particular interest for biotechnological applications due to their natural capacity to secrete plant cell wall-degrading enzymes that are known as carbohydrate-active enzymes (CAZy). The presence of easily metabolizable sugars such as glucose, whose concentrations increase during plant biomass hydrolysis, results in the repression of CAZy-encoding genes, in a process known as carbon catabolite repression (CCR), which is undesired for the purpose of large-scale enzyme production. To date, the C2H2 transcription factor CreA has been described as the major CC-repressor in Aspergillus spp. Although CreA-mediated CCR has been extensively studied, less is known about the regulation of CreA itself and the role of post-translational modifications in this process. In this work, phosphorylation sites were identified by mass spectrometry on A. nidulans CreA and subsequently four sites, S262, S268, T308 and S319, were chosen to be mutated to non-phosphorylatable residues before their effects on CCR in both CC-repressing and de-repressing conditions were studied. Sites S262, S268 and T308 are important for CreA protein accumulation and cellular localization and repression of enzyme activities. In contrast, site S319 is key for CreA degradation and induction of enzyme activities. All sites were shown to be important for glycogen and trehalose metabolism. This study highlights the importance of CreA phosphorylation sites for the regulation of CCR. Furthermore, these sites are interesting targets for biotechnological strain engineering without the need to delete essential genes which can result in undesired side effects.