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排序方式: 共有262条查询结果,搜索用时 15 毫秒
81.
Jennifer M. Seddon Jennifer R. Ovenden Helen L. Sneath Damien Broderick Christine L. Dudgeon Janet M. Lanyon 《Conservation Genetics》2014,15(6):1381-1392
Populations of marine mammals can show the signature of phylogeographical breaks and restricted connectivity despite the apparent lack of physical boundaries in the marine environment and their high dispersal abilities. Dugongs (Dugong dugon) do not appear to undertake regular migrations but may show localised movement related to water temperature or seagrass availability. Previous mitochondrial DNA studies suggested that despite a strong phylogeographic break in the Torres Strait, there is local panmixia in Australian waters. In this study, we conducted a comprehensive study of the four major dugong populations in southern Queensland. We analysed genotypes of 1,293 dugongs based on 24 microsatellite loci from the four major dugong locations in the region (from south to north): Moreton Bay, Great Sandy Straits, Hervey Bay and Shoalwater Bay. Diversity levels were similar across locations (observed heterozygosity 0.48–0.52, allelic richness 4.3–4.5). There was low but significant population differentiation in southern Queensland (FST ranged from 0.005 to 0.040 and Jost’s DEST ranged from 0.001 to 0.031 for microsatellite data). Bayesian clustering analysis implemented in STRUCTURE largely distinguished the southern Moreton Bay population from the three more northern populations. Twelve mitochondrial control region haplotypes identified from a subset of 182 samples confirmed significant population structuring (FST ranged from 0.16 to 0.28). These data suggested that the frequency and extent of dugong movements are insufficient to disrupt the long-term existence of at least two breeding populations in southern Queensland. 相似文献
82.
Recent advances in our understanding of the mechanisms for the biosynthesis of the complex iron-sulfur (Fe-S) containing prosthetic groups associated with [FeFe]-hydrogenases and nitrogenases have revealed interesting parallels. The biosynthesis of the H-cluster ([FeFe]-hydrogenase) and the FeMo-co (nitrogenase) occurs through a coordinated process that involves the modification of Fe-S cluster precursors synthesized by the general host cell machinery (Isc/Suf). Key modifications to the Fe-S precursors are introduced by the activity of radical S-adenosylmethionine (SAM) enzymes on unique scaffold proteins. The transfer of the modified clusters to a cofactor-less structural apo-protein completes maturation. Together these features provide the basis for establishing unifying paradigms for complex Fe-S cluster biosynthesis for these enzymes. 相似文献
83.
Kar Muthumani Megan C. Wise Kate E. Broderick Natalie Hutnick Jonathan Goodman Seleeke Flingai Jian Yan Chaoran B. Bian Janess Mendoza Colleen Tingey Christine Wilson Krzysztof Wojtak Niranjan Y. Sardesai David B. Weiner 《PloS one》2013,8(12)
An effective HIV vaccine will most likely require the induction of strong T-cell responses, broadly neutralizing antibodies (bNAbs), and the elicitation of antibody-dependent cellular cytotoxicity (ADCC). Previously, we demonstrated the induction of strong HIV/SIV cellular immune responses in macaques and humans using synthetic consensus DNA immunogens delivered via adaptive electroporation (EP). However, the ability of this improved DNA approach to prime for relevant antibody responses has not been previously studied. Here, we investigate the immunogenicity of consensus DNA constructs encoding gp140 sequences from HIV-1 subtypes A, B, C and D in a DNA prime-protein boost vaccine regimen. Mice and guinea pigs were primed with single- and multi-clade DNA via EP and boosted with recombinant gp120 protein. Sera were analyzed for gp120 binding and induction of neutralizing antibody activity. Immunization with recombinant Env protein alone induced low-titer binding antibodies with limited neutralization breath. In contrast, the synthetic DNA prime-protein boost protocol induced significantly higher antibody binding titers. Furthermore, sera from DNA prime-protein boost groups were able to neutralize a broader range of viruses in a panel of tier 1 clade B viruses as well as multiple tier 1 clade A and clade C viruses. Further investigation of synthetic DNA prime plus adaptive EP plus protein boost appears warranted. 相似文献
84.
P. Feutry A. Vergnes D. Broderick J. Lambourdière P. Keith J. R. Ovenden 《Molecular ecology》2013,22(6):1518-1530
Freshwater species on tropical islands face localized extinction and the loss of genetic diversity. Their habitats can be ephemeral due to variability in freshwater run‐off and erosion. Even worse, anthropogenic effects on these ecosystems are intense. Most of these species are amphidromous or catadromous (i.e. their life cycle includes a marine larval phase), which buffers them against many of these effects. A long pelagic larval duration (PLD) was thought to be critical to ensure the colonization and persistence in tropical islands, but recent findings indicated that several species with short PLDs are successful in those ecosystems. To test the potential of a short PLD in maintaining genetic connectivity and forestalling extirpation, we studied Kuhlia rupestris, a catadromous fish species with an extensive distribution in the western Pacific and Indian Oceans. Using a combination of molecular genetic markers (13 microsatellite loci and two gene regions from mtDNA) and modelling of larval dispersal, we show that a short PLD constrains genetic connectivity over a wide geographical range. Molecular markers showed that the short PLD did not prevent genetic divergence through evolutionary time and speciation has occurred or is occurring. Modelling of larvae dispersal suggested limited recent connectivity between genetically homogeneous populations across the Coral Sea. However, a short PLD can maintain connectivity on a subocean basin scale. Conservation and management of tropical diadromous species needs to take into account that population connectivity may be more limited than previously suspected in those species. 相似文献
85.
Kaushal R Pal P Alwell K Haverbusch M Flaherty M Moomaw C Sekar P Kissela B Kleindorfer D Chakraborty R Broderick J Deka R Woo D 《Human genetics》2007,121(5):601-607
Arachidonate 5-lipoxygenase activating protein (ALOX5AP) has been reported to demonstrate linkage and association with ischemic stroke and myocardial infarction. However,
replication studies have been conflicting and to date, a significant proportion of blacks have not been studied. We prospectively
recruited cases of ischemic stroke from all 16 hospitals in the Greater Cincinnati/Northern Kentucky region and demographically
matched them to stroke-free population-based controls. Single nucleotide polymorphisms (SNPs) were selected based on association
with ischemic stroke in prior studies. Allelic, genotypic and haplotypic association testing was performed using HAPLOVIEW.
Multiple logistic regression was used to control for the presence of traditional risk factors including hypertension, diabetes,
hypercholesterolemia and smoking. A total of 357 cases and 482 controls were genotyped. The SNPs, rs9579646 and rs4769874 were found to be significantly associated at both allelic (P = 0.019 and P < 10−4, respectively) and genotypic level with ischemic stroke among whites after correction for multiple testing. Haplotype association
was identified with ischemic stroke as well as ischemic stroke subtypes among whites. Although an overall haplotype association
with ischemic stroke was identified among blacks no evidence of association among individual haplotypes, alleles or genotypes
were observed. Allele frequencies for the SNPs examined were markedly different among whites and blacks. In conclusion, we
report significant association of variants of ALOX5AP with ischemic stroke and ischemic stroke subtypes among whites. No significant association was identified among blacks. 相似文献
86.
Shawn E. McGlynn Shane S. Ruebush Anatoli Naumov Lauren E. Nagy Alexandra Dubini Paul W. King Joan B. Broderick Matthew C. Posewitz John W. Peters 《Journal of biological inorganic chemistry》2007,12(4):443-447
The in vitro activation of the [FeFe] hydrogenase is accomplished by combining Escherichia coli cell extracts containing the heterologously expressed inactive HydA with extracts in which hydrogenase-specific maturation
proteins HydE, HydF, and HydG are expressed in concert. Interestingly, the process of HydA activation occurs rapidly and in
the absence of potential substrates, which suggests that the hydrogenase accessory proteins synthesize an H-cluster precursor
that can be quickly transferred to the hydrogenase enzyme to affect activation. HydA activity is observed to be dependent
on the protein fraction containing all three accessory proteins expressed in concert and cannot be accomplished with addition
of heat-treated extract or extract filtrate, suggesting that the activation of the hydrogenase structural protein is mediated
by interaction with the accessory assembly protein(s). These results represent the first important step in understanding the
process of H-cluster assembly and provide significant insights into hydrogenase maturation.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
87.
Ohiana Revuelta Yolanda M. León Juan A. Balbuena Annette C. Broderick Pablo Feliz Brendan J. Godley Juan A. Raga Jesús Tomás 《Biodiversity and Conservation》2014,23(6):1529-1539
Protected areas are considered essential elements for global biodiversity conservation. They may not necessarily result in an effective conservation of resources in developing countries due to lack of funding for management and enforcement. In addition, poor governance aligned with conflicts of economic interests related to their use can further threaten their integrity and persistence. In the Dominican Republic, the western beaches of the Jaragua National Park (JNP), a protected area which is also part of a UNESCO Biosphere Reserve, have been proposed for development using a mass-tourism model. One of the most charismatic species found in this area is the leatherback turtle (Dermochelys coriacea). In the present study, we assess hatching success, and factors affecting it, to determine the reproductive value across the area for the leatherback turtle. The main factors found driving hatching success at the study beaches are beach sector, incubation duration, date of lay and clutch size. Our results show that clutches in La Cueva (located in the buffer zone of the park) and Bahía de las Águilas (located inside the limits of the park) have an unusually high hatching success (~75 %) for this species, highlighting the importance of increasing protection efforts at these sites. We strongly recommend including La Cueva inside the limits of the JNP. 相似文献
88.
Boryana Stamova Glen C. Jickling Bradley P. Ander Xinhua Zhan DaZhi Liu Renee Turner Carolyn Ho Jane C. Khoury Cheryl Bushnell Arthur Pancioli Edward C. Jauch Joseph P. Broderick Frank R. Sharp 《PloS one》2014,9(7)
Aims
Epidemiological studies suggest that sex has a role in the pathogenesis of cardioembolic stroke. Since stroke is a vascular disease, identifying sexually dimorphic gene expression changes in blood leukocytes can inform on sex-specific risk factors, response and outcome biology. We aimed to examine the sexually dimorphic immune response following cardioembolic stroke by studying the differential gene expression in peripheral white blood cells.Methods and Results
Blood samples from patients with cardioembolic stroke were obtained at ≤3 hours (prior to treatment), 5 hours and 24 hours (after treatment) after stroke onset (n = 23; 69 samples) and compared with vascular risk factor controls without symptomatic vascular diseases (n = 23, 23 samples) (ANCOVA, false discovery rate p≤0.05, |fold change| ≥1.2). mRNA levels were measured on whole-genome Affymetrix microarrays. There were more up-regulated than down-regulated genes in both sexes, and females had more differentially expressed genes than males following cardioembolic stroke. Female gene expression was associated with cell death and survival, cell-cell signaling and inflammation. Male gene expression was associated with cellular assembly, organization and compromise. Immune response pathways were over represented at ≤3, 5 and 24 h after stroke in female subjects but only at 24 h in males. Neutrophil-specific genes were differentially expressed at 3, 5 and 24 h in females but only at 5 h and 24 h in males.Conclusions
There are sexually dimorphic immune cell expression profiles following cardioembolic stroke. Future studies are needed to confirm the findings using qRT-PCR in an independent cohort, to determine how they relate to risk and outcome, and to compare to other causes of ischemic stroke. 相似文献89.
Lucy A. Hawkes Andrew McGowan Annette C. Broderick Shannon Gore Damon Wheatley Jim White Matthew J. Witt Brendan J. Godley 《Ecology and evolution》2014,4(8):1255-1266
Management of species of conservation concern requires knowledge of demographic parameters, such as rates of recruitment, survival, and growth. In the Caribbean, hawksbill turtles (Eretmochelys imbricata) have been historically exploited in huge numbers to satisfy trade in their shells and meat. In the present study, we estimated growth rate of juvenile hawksbill turtles around Anegada, British Virgin Islands, using capture–mark–recapture of 59 turtles over periods of up to 649 days. Turtles were recaptured up to six times, having moved up to 5.9 km from the release location. Across all sizes, turtles grew at an average rate of 9.3 cm year−1 (range 2.3–20.3 cm year−1), and gained mass at an average of 3.9 kg year−1 (range 850 g–16.1 kg year−1). Carapace length was a significant predictor of growth rate and mass gain, but there was no relationship between either variable and sea surface temperature. These are among the fastest rates of growth reported for this species, with seven turtles growing at a rate that would increase their body size by more than half per year (51–69% increase in body length). This study also demonstrates the importance of shallow water reef systems for the developmental habitat for juvenile hawksbill turtles. Although growth rates for posthatching turtles in the pelagic, and turtles larger than 61 cm, are not known for this population, the implications of this study are that Caribbean hawksbill turtles in some areas may reach body sizes suggesting sexual maturity in less time than previously considered. 相似文献
90.
Carroll CC Whitt JA Peterson A Gump BS Tedeschi J Broderick TL 《American journal of physiology. Regulatory, integrative and comparative physiology》2012,302(8):R990-R995
Chronic consumption of acetaminophen (APAP) during exercise training leads to a reduction in tendon stiffness and modulus compared with a placebo. We explored whether this effect could be due to a reduction in tendon collagen content or cross-linking. Ten-week-old male Wistar rats (n = 50) were divided into placebo or APAP groups and into sedentary or treadmill-exercised groups. APAP (200 mg/kg) or saline was administered once daily by oral gavage. Rats in the exercise groups ran on a treadmill 5 days per week for 8 wk with progression to 60 min per day, 20 m/min, and 8° incline. After 8 wk, lyophilized Achilles tendon samples were assayed for the collagen-specific amino acid hydroxyproline and cross-linking [hydroxylyslpyridinoline (HP)] content by high-performance liquid chromatrography. Collagen content was not influenced by exercise or APAP (P > 0.05). Compared with placebo, tendon water content was 7% (P = 0.006, main effect) lower in animals consuming APAP (placebo: 54.79 ± 0.8%, APAP: 50.89 ± 1.2%). HP in the Achilles tendon was 36% greater (sedentary: 141 ± 15, exercise: 204 ± 26 mmol/mol collagen) in the exercise-trained rats independent of drug treatment (P = 0.020, main effect). Independent of exercise, HP content was 33% lower (P = 0.032, main effect) in the animals consuming APAP (placebo: 195 ± 21, APAP: 140 ± 19 mmol/mol collagen). Our data suggests that chronic consumption of APAP results in a reduction in collagen cross-linking and a loss of tissue water independent of chronic exercise. This reduction in cross-linking and water content could contribute to the decrease in tendon stiffness noted in humans chronically consuming APAP. 相似文献