Project description:In primates the amnion emerges through cavitation of the epiblast during implantation, whereas in other species by folding of the ectoderm later around gastrulation. How the mechanisms of amniogenesis diversified in evolution remains unknown. Here we employed the naïve-to-primed transition of human pluripotent stem cells (hPSC) to model peri-implantation epiblast development. We discovered that during this transition hPSC transiently gain the ability to differentiate into cavitating epithelium that transcriptionally matches the early amnion of human embryos. In contrast, primed hPSC produce cells resembling late amnion, uncovering an independent differentiation route. Unexpectedly, single-cell analysis of primate embryos revealed two transcriptionally distinct amniogenesis waves. The early wave occurs through a trophectoderm-like route and encompasses cavitation, whereas the late wave follows an ectoderm-like pathway during gastrulation. The discovery of two independent waves of amniogenesis both of which can be modelled in hPSC explains how amniogenesis through cavitation emerged during the evolution of primates.
Project description:Development and tissue maintenance require a supply of new cells, which are generated by division of stem cells and then specialised to perform their function. The differentiation process requires the tight control of gene expression, but this has been challenging to study in a systematic manner in adult stem cells, which are sparsely distributed in tissues. We have overcome these limitations by establishing a robust protocol to synchronise Drosophila female germline stem cell (GSC) differentiation in vivo, allowing us to perform transcriptome and translatome analyses at high temporal resolution during differentiation. As well as observing dynamic changes in mRNA level, promoter usage and exon inclusion, our data reveal that changing translation efficiency is the predominant regulatory mechanism during GSC differentiation. Indeed, changes in mRNA level are frequently buffered by changes in translation efficiency, including the translational repression of transcripts that will only be translated later during oocyte maturation or embryo development. Contrary to the expected linear accumulation of changes from stem cell to differentiated cell, our data reveal that differentiation occurs through two distinct waves of changes in both the transcriptome and translatome level.
Project description:This set includes individuals from 10 different primate species whose genomic DNA was used in an array-based comparative genomic hybridization (aCGH)using human cDNA microarrays to detect gene copy number variation across 10 primate species. An organism part comparison experiment design type compares tissues, regions, organs within or between organisms. Keywords: organism_part_comparison_design, array CGH Computed
Project description:Bacteria are known to respond to various environmental stimuli including nutrient deprivation, osmotic stress, and exposure to antibiotics. Our experimental data showed that P. aeruginosa biofilm formed in urinary catheters is very suseptible to gentamicin treatment when combined with exposure to surface acoustic waves Our goal was to establish whether P. aeruginosa is capable of specifically sensing the surface acoustic waves as well as to try and decipher the molecular mechanism underlying the increased biofilm suseptibility to antibiotics treatment
Project description:This set includes individuals from 10 different primate species whose genomic DNA was used in an array-based comparative genomic hybridization (aCGH)using human cDNA microarrays to detect gene copy number variation across 10 primate species. An organism part comparison experiment design type compares tissues, regions, organs within or between organisms. Keywords: organism_part_comparison_design, array CGH