Project description:East Africa’s Roots of Power: The microbiome, metabolomics, and the antimicrobial potential of Mondia whitei, an herbal medicinal plant
Project description:Purpose: Pseudomonas aeruginosa is a major cause of morbidity and mortality in patients with cystic fibrosis (CF). We provide an insight to the DNA auxotrophy of P. aeruginosa PASS4 isolate. Better understanding of P. aeruginosa adaptations in the CF lung environment can have a great impact in the development of specialised treatment regimes aimed at the eradications of P. aeruginosa infections. Methods: P. aeruginosa strains PAO1 and PASS4 were grown in minimal medium with either L-Asparagine or DNA as a carbon source, in biological triplicates. RNA was extracted and sequenced on Illumina HiSeq 1000 platform. The sequence reads that passed quality filters were analyzed using EdgePro and DESeq packages, as well as the Rockhopper tool. Results: We mapped > 10 million paired sequence reads per sample to the genome of P. aeruginosa PAO1 and identified a total of 576 genes differentially expressed by PASS4 when grown in DNA (P value < 0.01, log2 fold-change 1< to < -1), with 322 genes upregulated and 254 genes downregulated. There were a total of 423 genes differentially expressed by PAO1 when grown in DNA (P value < 0.01, log2 fold-change 1< to <-1), with 359 genes upregulated and 64 genes downregulated . A total of 129 transcripts displayed similar expression patterns in both organisms, with 112 being upregulated and 17 down-regulated. Conclusions: Our study identified that P. aeruginosa PASS4 was a purine auxotroph. Purine auxotropy may represent a viable microbial strategy for adaptation to DNA rich environments such as the CF lung.
Project description:Lepidosaurs include lizards, snakes, amphisbaenians and the tuatara, comprising a highly speciose evolutionary radiation with widely varying anatomical traits. Their stem-lineage originated by the late middle Permian 259 million years ago, but its early fossil record is poorly documented, obscuring the origins of key anatomical and functional traits of the group. Paliguana whitei, from the Early Triassic of South Africa, is an enigmatic fossil species with the potential to provide information on this. However, its anatomy and phylogenetic affinities remain highly uncertain, and have been debated since its discovery more than 100 years ago. We present microtomographic three-dimensional imaging of the cranial anatomy of P. whitei that clarifies these uncertainties, providing strong evidence for lepidosauromorph affinities based on the structure of the temporal region and the implantation of marginal dentition. Phylogenetic analysis including these new data recovers Paliguana as the earliest known stem-lepidosaur, within a long-lived group of early diverging lepidosauromorphs that persisted to at least the Middle Jurassic. Our results provide insights into cranial evolution on the lepidosaur stem-lineage, confirming that characteristics of pleurodont dental implantation evolved early on the lepidosaur stem-lineage. By contrast, key functional traits related to hearing (quadrate conch) and feeding (streptostyly) evolved later in the lepidosaur crown-group.
Project description:The diploid isolate EM93 is the main ancestor to the widely used Saccharomyces cerevisiae haploid laboratory strain, S288C. In this study, we first hybridise DNA from eight EM93 segregants from two tetrads to Affymetrix genechip S. cerevisiae Tiling 1.0R Arrays to generate a high-resolution overview of the genetic differences between EM93 and S288C. We show that EM93 is heterozygous for many polymorphisms, including large sequence polymorphisms, such as deletions and a Saccharomyces paradoxus introgression. We also find that many of the large sequence polymorphisms are associated with Ty-elements and sub-telomeric regions. We next utilize the hybridization profiles of the 3.2 million Tiling Array probes to identify 2,965 genetic markers, which we then used to design an EM93 genotyping array. By genotyping 120 EM93 tetrads, we deduced the structures of all EM93 chromosomes and found that the average EM93 meiosis produces 144 detectable recombination events, consisting of 87 crossover and 57 non-crossover events; we also identified 203 recombination hot-spots and provide evidence for crossover interference. We find that the effect of heterozygous large sequence polymorphisms on recombination is chromosome position-dependent, with sub-telomeric large sequence polymorphisms having no discernable effect on recombination but non-sub-telomeric large sequence polymorphisms reducing recombination. Finally, we find that recombination hotspots show limited conservation, with some but not all strain-specific hotspots being due to heterozygous non-sub-telomeric large sequence polymorphisms.
Project description:A new haloalkaliphilic species of Wenzhouxiangella, strain AB-CW3 was isolated from a system of alkaline soda lakes in the Kulunda Steppe. Its complete, circular genome was assembled from combined nanopore and illumina sequencing and its proteome was determined for three different experimental conditions: growth on Staphylococcus cells, casein, or peptone. AB-CW3 is an aerobic bacterium feeding mainly on proteins and peptides.