Project description:In this study, to unravel the influence of phylogenetic divergence and biogeography in shaping the composition and activity of Daboia venoms, we comparatively investigated the venoms of D. russelii from western India and D. palaestinae from Israel.
Project description:We applied numerical ecology methods to data produced with a human intestinal tract-specific phylogenetic microarray (the Aus-HIT Chip) to examine the biogeography of mucosa-associated bacteria along the human colon. The microbial DNA associated with matched biopsy tissue samples taken from the cecum, transverse colon, sigmoid colon and rectum of 10 healthy patients was examined. Consistent with previous studies, the profiles revealed a marked inter-subject variability; however, the numerical ecology methods of analysis allowed the subtraction of the subject effect from the data and revealed, for the first time, evidence of a longitudinal gradient for specific microbes along the colorectum: with Streptococcus, Comamonadaceae, Enterococcus and Lactobacillus in greatest abundance at the cecum, with a gradual decline in their relative abundance through to the rectum. Conversely, the analyses suggest that members of the Enterobacteriaceae increase in relative abundance towards the rectum. These differences were validated by quantitative PCR. We were also able to identify significant differences in the profiles, especially for the Streptococci, on the basis of gender. The results derived by these multivariate analyses are biologically intuitive, and suggestive that the biogeography of the colonic mucosa can be monitored for changes via cross-sectional and/or inception cohort studies.
Project description:Peanut (Arachis hypogaea) has a large (~2.7 Gbp) allotetraploid genome with closely related component genomes making its genome very challenging to assemble. Here we report genome sequences of its diploid ancestors (A. duranensis and A. ipaënsis). We show they are similar to the peanutâs A- and B-genomes and use them use them to identify candidate disease resistance genes, create improved tetraploid transcript assemblies, and show genetic exchange between peanutâs component genomes. Based on remarkably high DNA identity and biogeography, we conclude that A. ipaënsis may be a descendant of the very same population that contributed the B-genome to cultivated peanut. Whole Genome Bisulphite Sequencing of the peanut species Arachis duranensis and Arachis ipaensis.
Project description:The diazotroph Trichodesmium is an important contributor to marine dinitrogen (N2) fixation, supplying so-called new N to phytoplankton in typically N-limited ocean regions. Identifying how iron (Fe) and phosphorus (P) influence Trichodesmium activity and biogeography is an ongoing area of study, where predicting patterns of resource stress is complicated in part by the uncertain bioavailability of organically complexed Fe and P. Here, a comparison of 26 metaproteomes from picked Trichodesmium colonies identified significantly different patterns between three ocean regions: the western tropical South Pacific, the western North Atlantic, and the North Pacific Subtropical Gyre. Trichodesmium metaproteomes across these regions significantly differed in KEGG submodule signals, and vector fitting showed that dissolved Fe, phosphate, and temperature significantly correlated with regional proteome patterns. Populations in the western tropical South Pacific appeared to modulate their proteomes in response to both Fe and P stress, including a comparatively low relative abundance of the N2 fixation marker protein, NifH. Significant increases in the relative abundance of both Fe and P stress marker proteins previously validated in culture studies suggested that Trichodesmium populations in the western North Atlantic and North Pacific were P-stressed and Fe-stressed, respectively. These patterns recapitulate established regional serial and co-limitation patterns of resource stress on phytoplankton communities. Evaluating community stress patterns may therefore predict resource controls on diazotroph biogeography. These data highlight how Trichodesmium modulates its metabolism in the field and provide an opportunity to more accurately constrain controls on Trichodesmium biogeography and N2 fixation.
Project description:We applied numerical ecology methods to data produced with a human intestinal tract-specific phylogenetic microarray (the Aus-HIT Chip) to examine the biogeography of mucosa-associated bacteria along the human colon. The microbial DNA associated with matched biopsy tissue samples taken from the cecum, transverse colon, sigmoid colon and rectum of 10 healthy patients was examined. Consistent with previous studies, the profiles revealed a marked inter-subject variability; however, the numerical ecology methods of analysis allowed the subtraction of the subject effect from the data and revealed, for the first time, evidence of a longitudinal gradient for specific microbes along the colorectum: with Streptococcus, Comamonadaceae, Enterococcus and Lactobacillus in greatest abundance at the cecum, with a gradual decline in their relative abundance through to the rectum. Conversely, the analyses suggest that members of the Enterobacteriaceae increase in relative abundance towards the rectum. These differences were validated by quantitative PCR. We were also able to identify significant differences in the profiles, especially for the Streptococci, on the basis of gender. The results derived by these multivariate analyses are biologically intuitive, and suggestive that the biogeography of the colonic mucosa can be monitored for changes via cross-sectional and/or inception cohort studies. 10 patients, 5 males and 5 females. Four different locations along the colorectum.