Project description:How and when the Americas were populated remains contentious. Using ancient and modern genome-wide data, we find that the ancestors of all present-day Native Americans, including Athabascans and Amerindians, entered the Americas as a single migration wave from Siberia no earlier than 23 thousand years ago (KYA), and after no more than 8,000-year isolation period in Beringia. Native Americans diversified into two basal genetic branches around 13 KYA, one in North and South America and the other restricted to North America. Subsequent gene flow resulted in some Native Americans sharing ancestry with present-day East Asians and Australo-Melanesians, the latter possibly through the ancestors of Aleutian Islanders. Putative relict populations in South America, including the historical Pericúes and Fuego-Patagonians, are not directly related to modern Australo-Melanesians.
2015-07-20 | GSE70987 | GEO
Project description:Labyrinthula sp. diversity in North America
Project description:Expression profiling of the three clonotypic lineages dominating T. gondii populations in North America and Europe provides a first comprehensive view of the parasite transcriptome.
Project description:The Virochip microarray (version 4.0) was used to detect viruses in patients from North America with unexplained influenza-like illness at the onset of the 2009 H1N1 pandemic.
Project description:A comparision of soil microbial functional genes of three types of subtropical broad-leaved forests Microbial functional structure was significantly different among SBFs (P < 0.05). Compared to the DBF and the EBF, the MBF had higher alpha-diversity of functional genes but lower beta-diversity, and showed more complex functional gene networks.
Project description:Bicuspid aortic valve (BAV) is a common congenital cardiac anomaly, with an estimated incidence of 1-2%. It is responsible for the greatest burden of aortic valve disease in patients younger than 70 years in North America. We performed microRNA profiling in end-stage valve leaflets with BAV and TAV.
Project description:Members of the genus Equisetum are often referred to as “living fossils”, partly because they are the only extant representatives of the Equisetidae, a subclass that was once prominent in late Paleozoic forests. Several classes of specialized metabolites have been reported to occur in the genus Equisetum. However, while steady progress is being made with identifying individual novel metabolites of Equisetum, few if any analyses have focused on assessing the chemical diversity across the genus. The present study focused on three species: E. hyemale subsp. affine (rough horsetail or scouring rush), which is native to the temperate to artic portions of North America; E. arvense (common horsetail), which is endemic to the arctic and temperate regions of the northern hemisphere; and Equisetum telmateia subsp. braunii (Milde) Hauke (giant horsetail), which is native to western North America. Both below-ground rhizome and above-ground shoot material was harvested from each species, extracted with aqueous methanol, and subjected to non-targeted HPLC-QTOF-MS analysis. This research project was designed to lay the foundation for continued research to capture the metabolic capabilities in the ferns and fern allies.
Project description:Bark beetles (Coleoptera: Scolytinae) are pests of many forests around the world. The mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins, is a significant pest of western North American pine forests. The MPB is able to overcome the defences of pine trees through pheromone-assisted aggregation that results in a mass attack of host trees. These pheromones, both male and female produced, are believed to be biosynthesized in the midgut and/or fat body of these insects. We have used transcriptomics (RNA-seq) to identify transcripts differentially expressed between sexes and between tissues, with juvenile hormone III treatment, which is known to induce pheromone biosynthesis.
Project description:The common edible mushroom Agaricus bisporus is a basidiomycete that thrives on decaying plant material in the forests and grasslands of North America and Europe. It is adapted to forest litter and contributes to global carbon recycling, degrading cellulose, hemicellulose and lignin in plant biomass to oligomers and monomers. A. bisporus is also an edible mushroom that is widely cultivated and economically important. However, relatively little is known about how A. bisporus grows in this controlled environment and utilizes its substrate. Using transcriptomics and proteomics, we showed that changes in plant biomass degradation by A. bisporus occur throughout its life cycle. Ligninolytic genes were highly expressed during the spawning stage day 16 and had low expression during all the other growth stages which could indicate that lignin is not modified after the spawning stage. Our results also revealed differences in gene expression involved in cellulose and hemicellulose degradation between the first and second flushes. This could partially explain the reduction in the number of mushrooms during the second flush.
2015-09-23 | GSE65800 | GEO
Project description:Soil fungal biogeography across forests from eastern Asia and eastern North America 18S