Project description:We genotyped 135 new samples (121 samples from 10 Uralic-speaking and 14 samples from 8 non-Uralic-speaking populations) and combined these data with previously published data to characterize the population structure of Uralic-speaking populations in the context of their geographic neighbours across Eurasia
Project description:The history of click-speaking Khoe-San, and African populations in general, remains poorly understood. We genotyped ~2.3 million SNPs in 220 southern Africans and found that the Khoe-San diverged from other populations at least 100,000 years ago, but structure within the Khoe-San dated back to about 35,000 years ago. Genetic variation in various sub-Saharan populations did not localize the origin of modern humans to a single geographic region within Africa, instead, it indicated a history of admixture and stratification. We found evidence of adaptation targeting muscle function and immune response, potential adaptive introgression of UV-light protection, and selection predating modern human diversification involving skeletal and neurological development. These new findings illustrate the importance of African genomic diversity in understanding human evolutionary history .220 samples were analysed with the Illumina HumanOmni2.5-Quad BeadChip and are described herein.
Project description:Fusarium graminearum and F. verticillioides are devastating cereal pathogens with very different life history and ecological characteristics. F. graminearum is homothallic, and sexual spores are an important component of its life cycle, responsible for disease initiation. F. verticilloides is heterothallic, and produces only modest numbers of fruiting bodies, which are not a significant source of inoculum. To identify corresponding differences in the transcriptional program underlying fruiting body development in the two species, comparative expression was performed, analyzing six developmental stages. To accompany the transcriptional analysis, detailed morphological characterization of F. verticillioides development was performed and compared to a previous morphological analysis of F. graminearum. Morphological development was similar between the two species, except for the observation of possible trichogynes in F. verticillioides ascogonia, which have not been previously reported for any Fusarium species. Expression of over 9000 orthologous genes were measured for the two species. Functional assignments of highly expressed orthologous genes at each time-point revealed the majority of highly expressed genes fell into the M-bM-^@M-^XM-bM-^@M-^Xunclassified proteinsM-bM-^@M-^YM-bM-^@M-^Y category, reflecting the lack of characterization of genes for sexual development in both species. Simultaneous examination of morphological development and stage-specific gene expression suggests that degeneration of the paraphyses during sexual development is an apoptotic process. Expression of mating type genes in the two species differed, possibly reflecting the divergent roles they play in sexual development. Overall, the differences in gene expression reflect the greater role of fruiting bodies in the life cycle and ecology of F. graminearum versus F. verticillioides. mRNA were sampled and compared from six time points across sexual reproduction in two Fusarium species
Project description:Illumina single nucleotide polymorphism (SNP) array data were generated to study genome-wide patterns of genomic variation on Sumba and Timor, two small islands in eastern Indonesia. Both islands have a complex history from their initial settlement ~50,000 years ago, to admixture with Austronesian-speaking groups during the Neolithic farming expansion, and more recent intra-island gene flow and community interactions. As part of this detailed microgeographic study, we also collected associated cultural and linguistic information. The primary study location was Sumba, for which we genotyped SNPs in 235 individuals from eight communities that span the island, including groups that speak most of Sumba’s nine languages. Particular attention was paid to genomic data that are informative for recent aspects of population history, including reconstructions of past gene flow, socio-genetic interactions and possible signals of selection.
Project description:As a historical nomadic group in Central Asia, Kazaks have mainly inhabited the steppe zone from the Altay Mountains in the East to the Caspian Sea in the West. Fine scale characterization of the genetic profile and population structure of Kazaks would be invaluable for understanding their population history and modeling prehistoric human expansions across the Eurasian steppes. With this mind, we characterized the maternal lineages of 200 Kazaks from Jetisuu at mitochondrial genome level. Our results reveal that Jetisuu Kazaks have unique mtDNA haplotypes including those belonging to the basal branches of both West Eurasian (R0, H, HV) and East Eurasian (A, B, C, D) lineages. The great diversity observed in their maternal lineages may reflect pivotal geographic location of Kazaks in Eurasia and implies a complex population history. Comparative analyses of mitochondrial genomes of human populations in Central Eurasia reveal a common maternal genetic ancestry for Turko-Mongolian speakers and their expansion being responsible for the presence of East Eurasian maternal lineages in Central Eurasia. In addition, our analyses indicate maternal genetic affinity between the Sherpas from the Tibetan Plateau with the Turko-Mongolian speakers.
Project description:Fusarium graminearum and F. verticillioides are devastating cereal pathogens with very different life history and ecological characteristics. F. graminearum is homothallic, and sexual spores are an important component of its life cycle, responsible for disease initiation. F. verticilloides is heterothallic, and produces only modest numbers of fruiting bodies, which are not a significant source of inoculum. To identify corresponding differences in the transcriptional program underlying fruiting body development in the two species, comparative expression was performed, analyzing six developmental stages. To accompany the transcriptional analysis, detailed morphological characterization of F. verticillioides development was performed and compared to a previous morphological analysis of F. graminearum. Morphological development was similar between the two species, except for the observation of possible trichogynes in F. verticillioides ascogonia, which have not been previously reported for any Fusarium species. Expression of over 9000 orthologous genes were measured for the two species. Functional assignments of highly expressed orthologous genes at each time-point revealed the majority of highly expressed genes fell into the ‘‘unclassified proteins’’ category, reflecting the lack of characterization of genes for sexual development in both species. Simultaneous examination of morphological development and stage-specific gene expression suggests that degeneration of the paraphyses during sexual development is an apoptotic process. Expression of mating type genes in the two species differed, possibly reflecting the divergent roles they play in sexual development. Overall, the differences in gene expression reflect the greater role of fruiting bodies in the life cycle and ecology of F. graminearum versus F. verticillioides.
Project description:Transcriptome analyses during fruiting body formation in Fusarium graminearum and Fusarium verticillioides reflect species life history and ecology
Project description:Just as animal monozygotic twins can experience different environmental conditions by being reared apart, individual genetically-identical trees of the genus Populus can also be exposed to contrasting environmental conditions by being grown in different locations. As such, clonally-propagated Populus trees provide an opportunity to interrogate the impact of individual environmental history on current response to environmental stimuli. To test the hypothesis that current responses to an environmental stimulus, drought, are contingent on environmental history, the transcriptome-level drought responses of three economically important hybrid genotypes: DN34 (Populus deltoides x P. nigra); Walker (P. deltoides var. occidentalis x (P. laurifolia x P. nigra)); and, Okanese (‘Walker’ x (P. laurifolia x P. nigra)) derived from two different locations were compared. Strikingly, differences in transcript abundance patterns in response to drought were based on differences in geographic origin of clones for two of the three genotypes. This observation was most pronounced for the genotypes with the longest time since establishment and last common propagation. Differences in genome-wide DNA methylation paralleled the transcriptome level trends, where the clones with the most divergent transcriptomes and clone history had the most marked differences in the extent of total DNA methylation, suggesting an epigenetic basis for the clone-history-dependent transcriptome divergence. The data provide insights into the interplay between genotype and environment in the ecologically and economically important Populus genus, with implications for both the industrial application of Populus trees, and the evolution and persistence of these important tree species. 72 arrays total. 2 time points. 2 water regimes. 3 biological replicates per treatment