High-latitude adaptation through early floral induction in maize

Resumen del póster presentado en Jacksonville, Florida, entre el 17 y el 20 de marzo de 2016.- Unterseer, Sandra et al.Comparación del genoma del maíz liso y el maíz dentado para identificar genes relacionados con la adaptación a Europa.Funding acknowledgement: Federal Ministry of Education and Research (BMBF, Germany) within the AgroClustEr Synbreed - Synergistic plant and animal breeding (grant 0315528).Peer reviewe

Data from Unterseer et.al 2016 Genome Biology

This data package accompanies the following publication:<br><br>Unterseer et al. 2016 (Genome Biology 2016,<strong> 17</strong>:137)<br>A comprehensive study of the genomic differentiation<br>between temperate Dent and Flint maize.<br><strong>DOI: </strong>10.1186/s13059-016-1009-x<br><br>It contains a copy of the data files used in this paper as well as further accompanying files (see README.txt).<br><br

Characterization of genetic diversity, population structure and linkage disequilibrium within and across 35 European maize landraces using highdensity genomic data

Resumen del póster presentado en Jacksonville, Florida, entre el 17 y el 20 de marzo de 2016.Maize landraces represent a valuable source of genetic variation based on the following considerations: i) Only a small number of landraces served as sources for modern elite germplasm, therefore landraces can be expected to contain unexploited allelic variation. ii) Due to their adaptation to specific local environmental conditions they are likely to harbor unique favorable alleles for biotic and abiotic stress resistance. iii) Because of many generations of random mating, landraces are assumed to have low levels of linkage disequilibrium (LD) and no population substructure, making them ideal for genetic mapping. Up to date, these assumptions could not be appropriately tested as most previously reported diversity statistics and LD levels for maize landraces were based on measurements across landraces with only one individual per accession and /or low-density molecular marker data. We investigated genetic diversity, population structure and LD in a broad panel of 35 European maize landraces by genotyping 22 to 48 individuals per landrace with 609,442 single nucleotide polymorphism markers. Percentage of polymorphic markers and average nucleotide diversity pi indicated high genetic variation within landraces and Fst values suggested substantial genetic variation between landraces. Population structure analyses revealed genetic clustering of landraces mainly according to geographical origin and kernel type (Dent/Flint), absence of population substructure within landraces and moderate levels of admixture between landraces. Unlike most previous studies, which reported very low LD levels based on measurements across many landraces with few individuals, we found that within most landraces, LD decay distances (r2 < 0.2) were within 100 to 500 kb. Based on this unique and extensive dataset, we present results on the influence of sample size, sample composition and marker density on diversity and LD measurements within and across landraces.Funding acknowledgement: This study was funded by the Federal Ministry of Education and Research (BMBF, Germany) within the AgroClustEr Synbreed - Synergistic plant and animal breeding (grant 0315528) and by KWS SAAT SE under a PhD fellowship for M. Mayer.Peer reviewe

Is there an optimum level of diversity in utilization of genetic resources?

13 páginas y 6 figuras.Genome-enabled strategies for harnessing untapped allelic variation of landraces are currently evolving. The success of such approaches depends on the choice of source material. Thus, the analysis of different strategies for sampling allelic variation from landraces and their impact on population diversity and linkage disequilibrium (LD) is required to ensure the efficient utilization of diversity. We investigated the impact of different sampling strategies on diversity parameters and LD based on high-density genotypic data of 35 European maize landraces each represented by more than 20 individuals. On average, five landraces already captured ~95% of the molecular diversity of the entire dataset. Within landraces, absence of pronounced population structure, consistency of linkage phases and moderate to low LD levels were found. When combining data of up to 10 landraces, LD decay distances decreased to a few kilobases. Genotyping 24 individuals per landrace with 5k SNPs was sufficient for obtaining representative estimates of diversity and LD levels to allow an informed pre-selection of landraces. Integrating results from European with Central and South American landraces revealed that European landraces represent a unique and diverse spectrum of allelic variation. Sampling strategies for harnessing allelic variation from landraces depend on the study objectives. If the focus lies on the improvement of elite germplasm for quantitative traits, we recommend sampling from pre-selected landraces, as it yields a wide range of diversity, allows optimal marker imputation, control for population structure and avoids the confounding effects of strong adaptive alleles.This study was funded by the Federal Ministry of Education and Research (BMBF, Germany) within the AgroClustEr Synbreed—Synergistic plant and animal breeding (Grant 0315528), by the Bavarian State Ministry of the Environment and Consumer Protection within the project network BayKlimaFit (Project TGC01GCUFuE69741 “Improving cold tolerance in maize”), by the Spanish Ministry of Economy and Competitiveness (Project RF2011-00022-C02-01 “Regeneration and rationalization of the maize landraces from the Iberian Peninsula”) and by the KWS SAAT SE under a Ph.D. fellowship for Manfred Mayer. Bernardo Ordas acknowledges a grant from the program “Ramón y Cajal” of the Spanish Ministry of Economy and Competitiveness.Peer reviewe

Data from Mayer et.al 2017 TAG

This data package accompanies the following publication:<br><br>Mayer et al. 2017 (Theoretical and Applied Genetics)<br>Is there an optimum level of diversity in utilization of genetic resources?<div>doi:10.1007/s00122-017-2959-4<br><br>It contains a copy of the data files used in this paper as well as further accompanying files (see README.txt).<br></div

GDF15 promotes simultaneous astrocyte remodeling and tight junction strengthening at the blood–brain barrier

Perivascular astrocyte processes (PAP) surround cerebral endothelial cells (ECs) and modulate the strengthening of tight junctions to influence blood-brain barrier (BBB) permeability. Morphologically altered astrocytes may affect barrier properties and trigger the onset of brain pathologies. However, astrocyte-dependent mediators of these events remain poorly studied. Here, we show a pharmacologically driven elevated expression and release of growth/differentiation factor 15 (GDF15) in rat primary astrocytes and cerebral PAP. GDF15 has been shown to possess trophic properties for motor neurons, prompting us to hypothesize similar effects on astrocytes. Indeed, its increased expression and release occurred simultaneously to morphological changes of astrocytes in vitro and PAP, suggesting modulatory effects of GDF15 on these cells, but also neighboring EC. Administration of recombinant GDF15 was sufficient to promote astrocyte remodeling and enhance barrier properties between ECs in vitro, whereas its pharmacogenetic abrogation prevented these effects. We validated our findings in male high anxiety-related behavior rats, an animal model of depressive-like behavior, with shrunk PAP associated with reduced expression of the junctional protein claudin-5, which were both restored by a pharmacologically induced increase in GDF15 expression. Thus, we identified GDF15 as an astrocyte-derived trigger of astrocyte process remodeling linked to enhanced tight junction strengthening at the BBB

Additional file 7: Table S9. of A comprehensive study of the genomic differentiation between temperate Dent and Flint maize

Gene-wise level of differentiation of allele frequencies between landraces and Dent (left) and Flint (right) elite lines based on genotyping data. (XLSX 27 kb

Additional file 3: Table S3. of A comprehensive study of the genomic differentiation between temperate Dent and Flint maize

Gene-wise statistics for 1407 candidate genes identified in the 70 Dent (N = 876) and 66 Flint (N = 545) lines based on genotyping data. (XLSX 1238 kb

Additional file 6: Table S8. of A comprehensive study of the genomic differentiation between temperate Dent and Flint maize

Gene-wise nucleotide diversity π and F ST for flowering time candidate genes with at least 5 SNPs in the genic and 5 kb upstream region. (XLSX 24 kb

Additional file 2: Figure S1. of A comprehensive study of the genomic differentiation between temperate Dent and Flint maize

Metrics of the selection screens for 136 temperate inbred lines along the ten maize chromosomes based on genotyping data. (PDF 4242 kb