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101.
Sofie Meeus Hans Jacquemyn Olivier Honnay Thierry Pailler 《Plant Systematics and Evolution》2011,292(3-4):143-151
Surveys of the incompatibility status of island floras have shown a deficit in taxa possessing homomorphic or heteromorphic incompatibility. This observation provides strong evidence for Baker??s Rule (1967) in that self-incompatibility can impede these taxa of colonizing and establishing on islands. The woody liana Hugonia serrata Lam. (Linaceae) is an extremely rare plant species endemic to the Mascarene Islands of La Réunion and Mauritius in the southern Indian Ocean. Previous research has documented the existence of tristyly in this species, thereby raising the number of known tristylous families to six. However, data were based on a very small sampling size and currently no data on the self-incompatibility system of the species are available. In this study, we investigated in detail the breeding system of H. serrata. Calculation of reciprocity and precision indices based on measurements of reproductive organs in a much larger sample size confirmed tristyly in this species. This style?Cstamen polymorphism was accompanied by several ancillary polymorphisms in stigma size, stigma color, anther size and pollen size. The rigidity of the heteromorphic incompatibility system was tested using experimental hand-pollinations. Significantly fewer pollen tubes arrived at the ovary after self- and illegitimate pollination (7%) than after legitimate pollination (12%). Seed set after self-pollination (3.6%) was also much lower than after legitimate pollination (66.7%). Comparison of seed set after legitimate pollination with natural seed set showed evidence for outcross pollen limitation. Our results indicate that despite severe pollen limitation and limited mate availability the heteromorphic incompatibility system in H. serrata is still strict after colonization of La Réunion Island. Because H. serrata is extremely long-lived, these results suggest that establishment of heterostylous species on islands may have been favored by their long life span. 相似文献
102.
Gijsbers R Vets S De Rijck J Ocwieja KE Ronen K Malani N Bushman FD Debyser Z 《The Journal of biological chemistry》2011,286(48):41812-41825
LEDGF/p75 is a chromatin-interacting, cellular cofactor of HIV integrase that dictates lentiviral integration site preference. In this study we determined the role of the PWWP domain of LEDGF/p75 in tethering and targeting of the lentiviral pre-integration complex, employing potent knockdown cell lines allowing analysis in the absence of endogenous LEDGF/p75. Deletion of the PWWP domain resulted in a diffuse subnuclear distribution pattern, loss of interaction with condensed chromatin, and failure to rescue proviral integration, integration site distribution, and productive virus replication. Substitution of the PWWP domain of LEDGF/p75 with that of hepatoma-derived growth factor or HDGF-related protein-2 rescued viral replication and lentiviral integration site distribution in LEDGF/p75-depleted cells. Replacing all chromatin binding elements of LEDGF/p75 with full-length hepatoma-derived growth factor resulted in more integration in genes combined with a preference for CpG islands. In addition, we showed that any PWWP domain targets SMYD1-like sequences. Analysis of integration preferences of lentiviral vectors for epigenetic marks indicates that the PWWP domain is critical for interactions specifying the relationship of integration sites to regions enriched in specific histone post-translational modifications. 相似文献
103.
Understanding the in vivo regulation of hematopoietic stem cells (HSCs) will be critical to identifying key factors involved in the regulation of HSC self‐renewal and differentiation. The niche (microenvironment) in which HSCs reside has recently regained attention accompanied by a dramatic increase in the understanding of the cellular constituents of the bone marrow HSC niche. The use of sophisticated genetic models allowing modulation of specific lineages has demonstrated roles for mesenchymal‐derived elements such as osteoblasts and adipocytes, vasculature, nerves, and a range of hematopoietic progeny of the HSC as being participants in the regulation of the bone marrow microenvironment. Whilst providing significant insight into the cellular composition of the niche, is it possible to manipulate any given cell lineage in vivo without impacting, knowingly or unknowingly, on those that remain? J. Cell. Biochem. 112: 1486–1490, 2011. © 2011 Wiley‐Liss, Inc. 相似文献
104.
Guy Vranckx Hans Jacquemyn Joachim Mergeay Karen Cox Pieter Janssens Bie An Sofie Gielen Bart Muys Olivier Honnay 《Annals of botany》2014,113(6):1057-1069
Background and Aims
The interaction between forest fragmentation and predicted climate change may pose a serious threat to tree populations. In small and spatially isolated forest fragments, increased homozygosity may directly affect individual tree fitness through the expression of deleterious alleles. Climate change-induced drought stress may exacerbate these detrimental genetic consequences of forest fragmentation, as the fitness response to low levels of individual heterozygosity is generally thought to be stronger under environmental stress than under optimal conditions.Methods
To test this hypothesis, a greenhouse experiment was performed in which various transpiration and growth traits of 6-month-old seedlings of Quercus robur differing in multilocus heterozygosity (MLH) were recorded for 3 months under a well-watered and a drought stress treatment. Heterozygosity–fitness correlations (HFC) were examined by correlating the recorded traits of individual seedlings to their MLH and by studying their response to drought stress.Key Results
Weak, but significant, effects of MLH on several fitness traits were obtained, which were stronger for transpiration variables than for the recorded growth traits. High atmospheric stress (measured as vapour pressure deficit) influenced the strength of the HFCs of the transpiration variables, whereas only a limited effect of the irrigation treatment on the HFCs was observed.Conclusions
Under ongoing climate change, increased atmospheric stress in the future may strengthen the negative fitness responses of trees to low MLH. This indicates the necessity to maximize individual multilocus heterozygosity in forest tree breeding programmes. 相似文献105.
Hermien Janneke Schutte Sofie Jansen Matthias U. Schafroth J. Carel Goslings Nathalie van der Velde Sophia E. J. A. de Rooij 《PloS one》2014,9(5)
Background
Recent studies have shown that an increased bleeding tendency can be caused by Selective Serotonin Reuptake Inhibitors (SSRI) use. We aimed to investigate the occurrence and risk of blood transfusion in SSRI users compared to non-SSRI users in a cohort of patients admitted for hip-surgery.Methods
We conducted a retrospective cohort study of patients who underwent planned or emergency hip surgery from 1996 to 2011 in the Academic Medical Center in Amsterdam. Primary outcome measure was risk of blood transfusion. Secondary outcome measures were pre- and postoperative hemoglobin level. Multivariate logistic regression was used to adjust for potential confounders.Results
One-hundred and fourteen SSRI users were compared to 1773 non-SSRI users. Risk of blood transfusion during admission was increased for SSRI users in multivariate analyses (OR 1.7 [95% CI 1.1–2.5]). Also, pre-operative hemoglobin levels were lower in SSRI users (7.8±1.0 mmol/L) compared to non-SSRI users (8.0±1.0 mmol/L) (p = 0.042)), as were postoperative hemoglobin levels (6.2±1.0 mmol/L vs. 6.4±1.0 mmol/L respectively) (p = 0.017)).Conclusions
SSRI users undergoing hip surgery have an increased risk for blood transfusion during admission, potentially explained by a lower hemoglobin level before surgery. SSRI use should be considered as a potential risk indicator for increased blood loss in patients admitted for hip surgery. These results need to be confirmed in a prospective study. 相似文献106.
Sofie Ahlin Maja Olsson Anna S. Wilhelmson Kristina Sk?lén Jan Borén Lena M. S. Carlsson Per-Arne Svensson Kajsa Sj?holm 《PloS one》2014,9(4)
Chronically elevated serum levels of serum amyloid A (SAA) are linked to increased risk of cardiovascular disease. However, whether SAA is directly involved in atherosclerosis development is still not known. The aim of this study was to investigate the effects of adipose tissue-derived human SAA on atherosclerosis in mice. hSAA1+/− transgenic mice (hSAA1 mice) with a specific expression of human SAA1 in adipose tissue were bred with ApoE-deficient mice. The hSAA1 mice and their wild type (wt) littermates were fed normal chow for 35 weeks. At the end of the experiment, the mice were euthanized and blood, gonadal adipose tissue and aortas were collected. Plasma levels of SAA, cholesterol and triglycerides were measured. Atherosclerotic lesion areas were analyzed in the aortic arch, the thoracic aorta and the abdominal aorta in en face preparations of aorta stained with Sudan IV. The human SAA protein was present in plasma from hSAA1 mice but undetectable in wt mice. Similar plasma levels of cholesterol and triglycerides were observed in hSAA1 mice and their wt controls. There were no differences in atherosclerotic lesion areas in any sections of the aorta in hSAA1 mice compared to wt mice. In conclusion, our data suggest that adipose tissue-derived human SAA does not influence atherosclerosis development in mice. 相似文献
107.
108.
Karin Wolffhechel Jens Fagertun Ulrik Plesner Jacobsen Wiktor Majewski Astrid Sofie Hemmingsen Catrine Lohmann Larsen Sofie Katrine Lorentzen Hanne Jarmer 《PloS one》2014,9(9)
Appearance is known to influence social interactions, which in turn could potentially influence personality development. In this study we focus on discovering the relationship between self-reported personality traits, first impressions and facial characteristics. The results reveal that several personality traits can be read above chance from a face, and that facial features influence first impressions. Despite the former, our prediction model fails to reliably infer personality traits from either facial features or first impressions. First impressions, however, could be inferred more reliably from facial features. We have generated artificial, extreme faces visualising the characteristics having an effect on first impressions for several traits. Conclusively, we find a relationship between first impressions, some personality traits and facial features and consolidate that people on average assess a given face in a highly similar manner. 相似文献
109.
The discovery of morphologically very similar but genetically distinct species complicates a proper understanding of the link between biodiversity and ecosystem functioning. Cryptic species have been frequently observed to co-occur and are thus expected to be ecological equivalent. The marine nematode Halomonhystera disjuncta contains five cryptic species (GD1-5) that co-occur in the Westerschelde estuary. In this study, we investigated the effect of three abiotic factors (salinity, temperature and sulphide) on life-history traits of three cryptic H. disjuncta species (GD1-3). Our results show that temperature had the most profound influence on all life-cycle parameters compared to a smaller effect of salinity. Life-history traits of closely related cryptic species were differentially affected by temperature, salinity and presence of sulphides which shows that cryptic H. disjuncta species are not ecologically equivalent. Our results further revealed that GD1 had the highest tolerance to a combination of sulphides, high salinities and low temperatures. The close phylogenetic position of GD1 to Halomonhystera hermesi, the dominant species in sulphidic sediments of the Håkon Mosby mud volcano (Barent Sea, 1280 m depth), indicates that both species share a recent common ancestor. Differential life-history responses to environmental changes among cryptic species may have crucial consequences for our perception on ecosystem functioning and coexistence of cryptic species. 相似文献
110.
Wayne Reeve Julie Ardley Rui Tian Sofie De Meyer Jason Terpolilli Vanessa Melino Ravi Tiwari Ronald Yates Graham O’Hara John Howieson Mohamed Ninawi Xiaojing Zhang David Bruce Chris Detter Roxanne Tapia Cliff Han Chia-Lin Wei Marcel Huntemann James Han I-Min Chen Konstantinos Mavromatis Victor Markowitz Ernest Szeto Natalia Ivanova Ioanna Pagani Amrita Pati Lynne Goodwin Tanja Woyke Nikos Kyrpides 《Standards in genomic sciences》2014,9(3):540-550
Microvirga lotononidis is a recently described species of root-nodule bacteria that is an effective nitrogen- (N2) fixing microsymbiont of the symbiotically specific African legume Listia angolensis (Welw. ex Bak.) B.-E. van Wyk & Boatwr. M. lotononidis possesses several properties that are unusual in root-nodule bacteria, including pigmentation and the ability to grow at temperatures of up to 45°C. Strain WSM3557T is an aerobic, motile, Gram-negative, non-spore-forming rod isolated from a L. angolensis root nodule collected in Chipata, Zambia in 1963. This is the first report of a complete genome sequence for the genus Microvirga. Here we describe the features of Microvirga lotononidis strain WSM3557T, together with genome sequence information and annotation. The 7,082,538 high-quality-draft genome is arranged in 18 scaffolds of 104 contigs, contains 6,956 protein-coding genes and 84 RNA-only encoding genes, and is one of 20 rhizobial genomes sequenced as part of the DOE Joint Genome Institute 2010 Community Sequencing Program. 相似文献