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101.
Refinement of the Multiple Exostoses Locus (EXT2) to a 3-cM Interval on Chromosome 11 总被引:5,自引:2,他引:3
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Wim Wuyts Sarvan Ramlakhan Wim Van Hul Jacqueline T. Hecht Ans M. W. van den Ouweland Wendy H. Raskind Floris C. Hofstede Edwin Reyniers Dan E. Wells Bert de Vries Ernest U. Conrad April Hill Dmitry Zalatayev Jean Weissenbach Michael J. Wagner Egbert Bakker Dicky J. J. Halley Patrick J. Willems 《American journal of human genetics》1995,57(2):382-387
Hereditary multiple exostoses (EXT) is an autosomal dominant skeletal disorder characterized by the formation of multiple exostoses on the long bones. EXT is genetically heterogeneous, with at least three loci involved: one (EXT1) in the Langer-Giedion region on 8q23-q24, a second (EXT2) in the pericentromeric region of chromosome 11, and a third (EXT3) on chromosome 19p. In this study, linkage analysis in seven extended EXT families, all linked to the EXT2 locus, refined the localization of the EXT2 gene to a 3-cM region flanked by D11S1355 and D11S1361/D11S554. This implies that the EXT2 gene is located at the short arm of chromosome 11, in band 11p11-p12. The refined localization of EXT2 excludes a number of putative candidate genes located in the pericentromeric region of chromosome 11 and facilitates the process of isolating the EXT2 gene. 相似文献
102.
J. M. Collée Hendrik G. de Vries Hans Scheffer Dicky J. J. Halley Leo P. ten Kate 《Human genetics》1998,102(5):587-590
Cystic fibrosis (CF) is one of the most common autosomal recessive disorders in white populations. Significant regional differences
in CF mutations among affected individuals have been reported. We have studied the geographic distribution of the relative
frequencies of the three most common Dutch CF mutations, ΔF508, A455E, and G542X, by analyzing data on area of residence of
CF patients. Significantly higher relative frequencies of the A455E mutation and the G542X mutation were observed in the South-West
and the South-East, respectively. A uniform distribution of relative frequencies was found for the ΔF508 mutation. The results
of our study show that, even in a small country such as The Netherlands, certain CF mutations may be more common in one region
than in another.
Received: 19 February 1998 / Accepted: 20 February 1998 相似文献
103.
N Lübcker J Dabrowski TA Zengeya PJ Oberholster G Hall S Woodborne 《African Journal of Aquatic Science》2016,41(4):399-411
The alien invasive silver carp Hypophthalmichthys molitrix established a self-sustaining feral population in an oligotrophic impoundment, Flag Boshielo Dam, in South Africa. The ability of this population to persist in a dam with low algal biomass (median annual suspended chlorophyll a = 0.08 µg l?1), and limited access to rivers considered large enough for successful spawning, has implications for their invasive potential in other systems. Stomach content and stable isotope analysis were used to assess the trophic ecology of H. molitrix, which was then compared with indigenous Mozambique tilapia Oreochromis mossambicus, on a seasonal basis during 2011. Hypophthalmichthys molitrix are generalist filter feeders, with a diet consisting primarily of sediment, vegetative detritus, dinoflagellates and diatoms. The dominance of sediments in their stomachs suggests occasional benthic scavenging. However, H. molitrix occupied a higher trophic level (TL = 2.8) than expected, suggesting that this population subsidised their diet with an unidentified dietary constituent, characterised by enriched nitrogen values. Although the stomach contents indicated dietary overlap between H. molitrix and O. mossambicus, stable isotopes revealed fine-scale resource partitioning, despite both species occupying the same trophic level. Nonetheless, the persistence of this feral H. molitrix population in an oligotrophic impoundment highlights their phenotypic plasticity. 相似文献
104.
PJ Gokhale 《Biotechnic & histochemistry》2016,91(8):540-548
The extraction of statistically meaningful quantitative information from microscopy images is increasingly important for modern biological research. Obtaining accurate, quantitative information from biological specimens, however, is a complex process that requires optimization of several parameters. One must consider the number of probes, fluorescent channels required, type of plate to be used, number of fields to be acquired and optimal resolution for image acquisition. The extraction of information from images is dependent on and can be aided greatly by careful consideration of the factors involved in the image acquisition process. I summarize here the general principles behind the imaging and software technology that is used to quantify images and highlight particular issues of concern for critically applying image quantitation techniques for research. 相似文献
105.
106.
Effect of oxygen deficiency on nitrogen assimilation and amino acid metabolism of soybean root segments 总被引:1,自引:0,他引:1
Plants submitted to O2 deficiency present a series of biochemical modifications, affecting overall root metabolism. Here, the effect of hypoxia on the metabolic fate of 15N derived from 15NO3 ?, 15NO2 ? and 15NH4 + in isolated soybean root segments was followed by gas chromatography–mass spectrometry, to provide a detailed analysis of nitrogen assimilation and amino acid biosynthesis under hypoxia. O2 deficiency decreased the uptake of the nitrogen sources from the solution, as ratified by the lower 15NO3 ? and 15NH4 + enrichment in the root segments. Moreover, analysis of endogenous NO2 ? and 15NH4 + levels suggested a slower metabolism of these ions under hypoxia. Accordingly, regardless of the nitrogen source, hypoxia reduced total 15N incorporation into amino acids. Analysis of 15N enrichment patterns and amino acid levels suggest a redirecting of amino acid metabolism to alanine and γ-aminobutyric acid synthesis under hypoxia and a differential sensitivity of individual amino acid pathways to this stress. Moreover, the role of glutamine synthetase in nitrogen assimilation both under normoxia and hypoxia was ratified. In comparison with 15NH4 +, 15NO2 ? assimilation into amino acids was more strongly affected by hypoxia and NO2 ? accumulated in root segments during this stress, indicating that nitrite reductase may be an additional limiting step. NO2 ? accumulation was associated with a higher nitric oxide emission. 15NO3 ? led to much lower 15N incorporation in both O2 conditions, probably due to the limited nitrate reductase activity of the root segments. Overall, the present work shows that profound alterations of root nitrogen metabolism occur during hypoxic stress. 相似文献
107.
108.
Tamar E. Carter Halley Malloy Alexandre Existe Gladys Memnon Yves St. Victor Bernard A. Okech Connie J. Mulligan 《PloS one》2015,10(10)
Hispaniola, comprising Haiti and the Dominican Republic, has been identified as a candidate for malaria elimination. However, incomplete surveillance data in Haiti hamper efforts to assess the impact of ongoing malaria control interventions. Characteristics of the genetic diversity of Plasmodium falciparum populations can be used to assess parasite transmission, which is information vital to evaluating malaria elimination efforts. Here we characterize the genetic diversity of P. falciparum samples collected from patients at seven sites in Haiti using 12 microsatellite markers previously employed in population genetic analyses of global P. falciparum populations. We measured multiplicity of infections, level of genetic diversity, degree of population geographic substructure, and linkage disequilibrium (defined as non-random association of alleles from different loci). For low transmission populations like Haiti, we expect to see few multiple infections, low levels of genetic diversity, high degree of population structure, and high linkage disequilibrium. In Haiti, we found low levels of multiple infections (12.9%), moderate to high levels of genetic diversity (mean number of alleles per locus = 4.9, heterozygosity = 0.61), low levels of population structure (highest pairwise Fst = 0.09 and no clustering in principal components analysis), and moderate linkage disequilibrium (ISA = 0.05, P<0.0001). In addition, population bottleneck analysis revealed no evidence for a reduction in the P. falciparum population size in Haiti. We conclude that the high level of genetic diversity and lack of evidence for a population bottleneck may suggest that Haiti’s P. falciparum population has been stable and discuss the implications of our results for understanding the impact of malaria control interventions. We also discuss the relevance of parasite population history and other host and vector factors when assessing transmission intensity from genetic diversity data. 相似文献
109.
Emily A. Miller Halley E. Froehlich Dennis E. Cocherell Michael J. Thomas Joseph J. Cech Jr. A. Peter Klimley Nann A. Fangue 《Environmental Biology of Fishes》2014,97(6):647-658
Ultrasonic telemetry is a preferred method for fish-movement studies. Despite surgical tag implantation being the most common method for affixing tags, many studies lack tests addressing the assumption that tagging has no effect on fish performance or survival. The threatened, anadromous green sturgeon, Acipenser medirostris, has little documentation concerning its movements. We evaluated the effects of surgery and tag implantation in juveniles. We compared three groups: tagged fish with dummy transmitters implanted in the peritoneal cavity, sham fish that underwent surgery without tag implantation, and control fish that were handled and anesthetized but did not undergo surgery. We found no differences in growth or critical swimming velocity among groups. Photos of incisions were taken towards the beginning and at the end of the study to assess inflammation and to score each incision for closure and suture retention. Inflammation declined similarly for tagged and sham fish during the study. Ucrit was not related to the extent of inflammation or to post-surgery time. All fish showed healing during the study (ca. 140 day duration) and 10 % of tagged and sham fish showed signs of inflammation by the study end. These results suggest that current ultrasonic surgical tagging methods do not significantly affect the short-term growth or swimming performance of juvenile green sturgeon. Additionally, effects of surgery can be mitigated by minimizing the number of suture entry points and by using rapid-absorbing sutures. 相似文献
110.
Alfredo Wulff Halley Caixeta Oliveira Elzira Elisabeth Saviani Ione Salgado 《Nitric oxide》2009,21(2):132-139
Mitochondria recently have emerged as important sites in controlling NO levels within the cell. In this study, the synthesis of nitric oxide (NO) from nitrite and its degradation by mitochondria isolated from Arabidopsis thaliana were examined. Oxygen and NO concentrations in the reaction medium were measured with specific electrodes. Nitrite inhibited the respiration of isolated A. thaliana mitochondria, in competition with oxygen, an effect that was abolished or potentiated when electron flow occurred via alternative oxidase (AOX) or cytochrome c oxidase (COX), respectively. The production of NO from nitrite was detected electrochemically only under anaerobiosis because of a superoxide-dependent process of NO degradation. Electron leakage from external NAD(P)H dehydrogenases contributed the most to NO degradation as higher rates of Amplex Red-detected H2O2 production and NO consumption were observed in NAD(P)H-energized mitochondria. Conversely, the NO-insensitive AOX diminished electron leakage from the respiratory chain, allowing the increase of NO half-life without interrupting oxygen consumption. These results show that the accumulation of nitric oxide derived from nitrite reduction and the superoxide-dependent mechanism of NO degradation in isolated A. thaliana mitochondria are influenced by the external NAD(P)H dehydrogenases and AOX, revealing a role for these alternative proteins of the mitochondrial respiratory chain in the control of NO levels in plant cells. 相似文献