LSD1-mediated enhancer silencing attenuates retinoic acid signalling during pancreatic endocrine cell development

Developmental progression depends on temporally defined changes in gene expression mediated by transient exposure of lineage intermediates to signals in the progenitor niche. To determine whether cell-intrinsic epigenetic mechanisms contribute to signal-induced transcriptional responses, here we manipulate the signalling environment and activity of the histone demethylase LSD1 during differentiation of hESC-gut tube intermediates into pancreatic endocrine cells. We identify a transient requirement for LSD1 in endocrine cell differentiation spanning a short time-window early in pancreas development, a phenotype we reproduced in mice. Examination of enhancer and transcriptome landscapes revealed that LSD1 silences transiently active retinoic acid (RA)-induced enhancers and their target genes. Furthermore, prolonged RA exposure phenocopies LSD1 inhibition, suggesting that LSD1 regulates endocrine cell differentiation by limiting the duration of RA signalling. Our findings identify LSD1-mediated enhancer silencing as a cell-intrinsic epigenetic feedback mechanism by which the duration of the transcriptional response to a developmental signal is limited

Not Available

Not AvailableA total of 113 rhizobacteria were isolated from different rhizotic zones of pigeonpea using nine selective and three non-selective media. Maximum isolates were obtained on King's A medium closely followed by King's B and nutrient agar. Seed treatment using four isolates viz. RS29, RS39, RS41 and RP3 resulted in 90% seed germination in contrast to 50% obtained in untreated control after 72h of incubation. Radicle length was also influenced significantly by some of the isolates. None of the isolates obtained from different rhizotic zones on EMB agar could promote seed germination or seedling growth. In contrast all the isolates obtained from rhizosphere on SEM or Nfb media could stimulate seed germination or radicle length. The study indicate that media like soil extract agar (SEA), N-free malate (Nfb) and Pseudomonas fluorescens agar (PFA) could yield higher percentage of plant growth promoting rhizobacteria. Out of the 42 isolates RS34, ER17, RP7 and RS41 increased shoot height and 25 isolates produced higher shoot dry biomass as compared to uninoculated control whereas isolates RS45, RS36, RS57, ER23, RP24 influenced root dry biomass significantly.Not Availabl

Missing mass spectroscopy of 8^{8}He and 10^{10}He by (d,3^{3}He) reaction

International audienceWe present the first missing mass spectrum of the unbound system 10He obtained from one nucleon transfer $^{11}$Li(d,$^{3}$He) reaction at 50 A MeV. We found rather large yields for the $^{6}$He + 4n decay channel especially for higher excitation energy, which suggest the importance of the $^{6}$He + 4n structure in $^{10}$He