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Synopsis A pregnant female of the Dwarf deep-sea shark, Squaliolus laticaudus with four embryos was caught by the nocturnal longline vessel “Progress?o” from southern Brazil, on September 1999. It was
donated by the fishermen. Embryos ranged in size 105 – 100 mm of total length. The aim of this article is to contribute to
the knowledge of the Dwarf deep-sea shark reproduction and distribution on the Brazilian coast. It is been considered the
first record to know about pregnant Dwarf deep-sea shark in the world. 相似文献
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Association Mapping: Critical Considerations Shift from Genotyping to Experimental Design 总被引:1,自引:0,他引:1
Sean Myles Jason Peiffer Patrick J. Brown Elhan S. Ersoz Zhiwu Zhang Denise E. Costich Edward S. Buckler 《The Plant cell》2009,21(8):2194-2202
The goal of many plant scientists'' research is to explain natural phenotypic variation in terms of simple changes in DNA sequence. Traditionally, linkage mapping has been the most commonly employed method to reach this goal: experimental crosses are made to generate a family with known relatedness, and attempts are made to identify cosegregation of genetic markers and phenotypes within this family. In vertebrate systems, association mapping (also known as linkage disequilibrium mapping) is increasingly being adopted as the mapping method of choice. Association mapping involves searching for genotype-phenotype correlations in unrelated individuals and often is more rapid and cost-effective than traditional linkage mapping. We emphasize here that linkage and association mapping are complementary approaches and are more similar than is often assumed. Unlike in vertebrates, where controlled crosses can be expensive or impossible (e.g., in humans), the plant scientific community can exploit the advantages of both controlled crosses and association mapping to increase statistical power and mapping resolution. While the time and money required for the collection of genotype data were critical considerations in the past, the increasing availability of inexpensive DNA sequencing and genotyping methods should prompt researchers to shift their attention to experimental design. This review provides thoughts on finding the optimal experimental mix of association mapping using unrelated individuals and controlled crosses to identify the genes underlying phenotypic variation. 相似文献
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Richard J. Challis Jo Hepworth Céline Mouchel Richard Waites Ottoline Leyser 《Plant physiology》2013,161(4):1885-1902
Strigolactones (SLs) are carotenoid-derived phytohormones with diverse roles. They are secreted from roots as attractants for arbuscular mycorrhizal fungi and have a wide range of endogenous functions, such as regulation of root and shoot system architecture. To date, six genes associated with SL synthesis and signaling have been molecularly identified using the shoot-branching mutants more axillary growth (max) of Arabidopsis (Arabidopsis thaliana) and dwarf (d) of rice (Oryza sativa). Here, we present a phylogenetic analysis of the MAX/D genes to clarify the relationships of each gene with its wider family and to allow the correlation of events in the evolution of the genes with the evolution of SL function. Our analysis suggests that the notion of a distinct SL pathway is inappropriate. Instead, there may be a diversity of SL-like compounds, the response to which requires a D14/D14-like protein. This ancestral system could have been refined toward distinct ligand-specific pathways channeled through MAX2, the most downstream known component of SL signaling. MAX2 is tightly conserved among land plants and is more diverged from its nearest sister clade than any other SL-related gene, suggesting a pivotal role in the evolution of SL signaling. By contrast, the evidence suggests much greater flexibility upstream of MAX2. The MAX1 gene is a particularly strong candidate for contributing to diversification of inputs upstream of MAX2. Our functional analysis of the MAX1 family demonstrates the early origin of its catalytic function and both redundancy and functional diversification associated with its duplication in angiosperm lineages.Strigolactones (SLs) are carotenoid-derived terpenoid lactones, which have been identified as signaling molecules in several areas of plant biology. SLs were first identified as germination stimulants for seeds of plants in the genus Striga (Cook et al., 1966). Striga spp. and related Orobanchaceae are parasitic weeds that germinate in response to host plant root exudates and develop haustoria to penetrate the host tissue and draw nutrients. Striga spp. are major agricultural pests across much of tropical and subtropical Asia and are present in two-thirds of arable land in Africa, where they are the greatest biological cause of crop damage (Humphrey and Beale, 2006). The secretion of SLs by roots, despite its exploitation by Striga spp., has been preserved because it also serves to recruit arbuscular mycorrhizal (AM) fungi (Akiyama et al., 2005). AM fungi form symbiotic associations with most land plants, whereby the plant gains access to mineral nutrients, particularly phosphate, absorbed by the fungal hyphae, and in exchange the fungus gains fixed carbon from the plant. In several flowering plant species, SL production is correspondingly increased when phosphate availability is limiting, thereby presumably increasing fungal recruitment (Yoneyama et al., 2007, 2012).AM symbioses can be traced back to the origin of land plants, between 360 to 450 million years ago, and are thought to have facilitated plant colonization of the terrestrial environment (Simon et al., 1993). Although AM symbiosis has been lost from some lineages, such as Brassicaceae, it is still widespread, with 80% of land plants able to form associations with AM fungi (Schüssler et al., 2001). In support of a similarly ancient origin for SL secretion, the liverwort Marchantia polymorpha and the moss Physcomitrella patens, both basal land plant groups, have been shown to produce SLs (Proust et al., 2011; Delaux et al., 2012). Furthermore, the presence of SLs in charophyte algae indicates that SL production may predate the emergence of land plants (Delaux et al., 2012), and Chara corallina responds to SL treatment by producing longer rhizoids (Delaux et al., 2012). In P. patens, SLs appear to act as intercolony coordination signals, regulating colony growth and competition by controlling flexible developmental processes such as protonemal branching (Proust et al., 2011; Delaux et al., 2012). In flowering plants, SLs have also been implicated in development, including several processes regulated in response to phosphate limitation (Kohlen et al., 2011; Ruyter-Spira et al., 2011). In particular, SLs play important roles in the regulation of shoot branching in higher plants (Gomez-Roldan et al., 2008; Umehara et al., 2008). It is through work on their effects on shoot branching that some of the genes in the SL pathway were first identified.Arabidopsis (Arabidopsis thaliana) MORE AXILLARY GROWTH (MAX) mutants show increased branching and reduced stature relative to wild-type plants, and analogous phenotypes have been identified in pea (Pisum sativum; RAMOSUS [RMS]), petunia (Petunia hybrida; DECREASED APICAL DOMINANCE [DAD]), and rice (Oryza sativa; DWARF [D] or HIGH TILLERING DWARF) mutants. So far, six MAX/RMS/DAD/D genes have been identified, with roles in SL biosynthesis or signaling. MAX3/RMS5/HIGH TILLERING DWARF1/D17 (Booker et al., 2004; Johnson et al., 2006; Zou et al., 2006) and MAX4/RMS1/DAD1/D10 (Sorefan et al., 2003; Snowden et al., 2005; Arite et al., 2007) encode carotenoid cleavage dioxygenases (CCD7 and CCD8, respectively). These enzymes are capable of sequentially cleaving the carotenoid 9-cis-β-carotene to produce a novel compound, carlactone, a putative strigolactone intermediate (Alder et al., 2012). Another biosynthetic gene, D27, was originally mutationally defined in rice (Lin et al., 2009), and reverse genetic approaches in Arabidopsis indicate a similar function in this species (Waters et al., 2012a). D27 is an iron-containing protein with isomerase activity that can produce the 9-cis-β-carotene substrate for MAX3 from all-trans-β-carotene (Alder et al., 2012). The fourth gene known to be involved in SL biosynthesis, MAX1, encodes a cytochrome p450 monooxygenase belonging to the CYP711 clan (Booker et al., 2005). Mutant phenotypes associated with this gene have so far only been identified in one species, Arabidopsis, although the gene is present in all tracheophytes (Nelson et al., 2008). The excessive-branching phenotypes associated with mutations in all of these genes can be rescued by exogenous application of SL, while mutants in the two remaining genes in the pathway are SL insensitive. D14 encodes an α/β hydrolase, which is proposed to act in signaling or in the hydrolysis of SLs to an active compound and provides specificity to signaling via MAX2/RMS4/D3, an F-box protein that mediates both SL signaling and signaling of karrikins (Stirnberg et al., 2002, 2007; Ishikawa et al., 2005; Johnson et al., 2006; Arite et al., 2009; Hamiaux et al., 2012; Waters et al., 2012b). Karrikins are compounds structurally related to SLs that are found in smoke and act as germination stimulants for plants that colonize ground cleared by forest fires (Nelson et al., 2010; Waters et al., 2012b).Homology searches described in the original publications for each of the MAX/D genes revealed two general patterns. MAX1, MAX3, and MAX4 are members of widespread gene families and are more closely related to nonplant sequences than to other plant genes (Sorefan et al., 2003; Booker et al., 2005). By contrast, MAX2, D14, and D27 are members of plant-specific gene families (Stirnberg et al., 2002; Arite et al., 2009; Lin et al., 2009). These contrasting patterns of SL pathway gene ancestry and the diverse biological roles of SLs present interesting evolutionary questions. The identification of SLs and SL responses in charophyte algae demonstrate their early evolution, but these species lack many of the genes required for SL synthesis and signaling in angiosperms. In an attempt to trace the evolution of the angiosperm SL pathway, we conducted a phylogenetic analysis of the known SL biosynthesis and signaling genes, allowing the correlation of events in the evolution of the genes with the evolution of SL function. Our analysis suggests that the notion of a distinct SL pathway is inappropriate. Instead, the angiosperm pathway seems to have been defined by the rapid evolution of MAX2 in early land plants. Upstream of MAX2, there appears to be much greater flexibility, especially in the requirements for the synthesis of SLs. We present evidence for the contribution of MAX1 to this flexibility. Our functional analysis of MAX1 orthologs from phylogenetically diverse species demonstrates the early origin of its catalytic activity and both redundancy and functional diversification associated with its duplication in angiosperm lineages. 相似文献
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Zoltan Lohinai Peter Dome Zsuzsa Szilagyi Gyula Ostoros Judit Moldvay Balazs Hegedus Balazs Dome Glen J. Weiss 《PloS one》2016,11(1)
Backgrounds
Based on in vitro data and results of a recent drug repositioning study, some medications approved by the FDA for the treatment of various non-malignant disorders were demonstrated to have anti-SCLC activity in preclinical models. The aim of our study is to confirm whether use of these medications is associated with survival benefit.Methods
Consecutive patients with pathologically confirmed, stage 4 SCLC were analyzed in this retrospective study. Patients that were prescribed statins, aspirin, clomipramine (tricyclic antidepressant; TCA), selective serotonin reuptake inhibitors (SSRIs), doxazosin or prazosin (α1-adrenergic receptor antagonists; ADRA1) were identified.Results
There were a total of 876 patients. Aspirin, statins, SSRIs, ADRA1, and TCA were administered in 138, 72, 20, 28, and 5 cases, respectively. A statistically significant increase in median OS was observed only in statin-treated patients when compared to those not receiving any of the aforementioned medications (OS, 8.4 vs. 6.1 months, respectively; p = 0.002). The administration of SSRIs, aspirin, and ADRA1 did not result in a statistically significant OS benefit (median OS, 8.5, 6.8, and 6.0 months, respectively). The multivariate Cox model showed that, besides age and ECOG PS, radiotherapy was an independent survival predictor (Hazard Ratio, 2.151; 95% confidence interval, 1.828–2.525; p <0.001).Conclusions
Results of drug repositioning studies using only preclinical data or small numbers of patients should be treated with caution before application in the clinic. Our data demonstrated that radiotherapy appears to be an independent survival predictor in stage 4 SCLC, therefore confirming the results of other prospective and retrospective studies. 相似文献8.
Mahboobi Mahdieh Sedighian Hamid Malekara Ehsan Khalili Saeed Rahbar Mohammad Reza Ahmadi Zanoos Kobra Halabian Raheleh Jahangiri Abolfazl 《International journal of peptide research and therapeutics》2021,27(2):1019-1026
International Journal of Peptide Research and Therapeutics - Epsilon toxin (ETX) is one of four lethal toxins of Clostridium perfringens produced by types B and D of the pathogen. This pore-forming... 相似文献
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Todd Sanders 《American anthropologist》2003,105(2):338-352
African notions of witchcraft are neither archaic nor static but are highly flexible and deeply attuned to the conundrums of our contemporary world. Many anthropologists have recently argued that notions of the African witch provide commentaries on the meaning and merit of modernity as experienced in different historical and cultural settings. By exploring one particular type of witchcraft —that involving rain—amongst the lhanzu of Tanzania, this article suggests instead that some forms of witchcraft may be more pertinent to understanding local notions of "tradition" than "modernity." It is argued that the process of identifying rain witches provides lhanzu men and women with a way to circumscribe, contemplate, and, ultimately, reassert the veracity and significance of a conceptual category they call "tradition." The article concludes by critiquing the homogenizing effects of terms like the African witch and African witchcraft, compelling us to think in terms of pluralities rather than singulars. [Keywords: witchcraft, modernity, tradition, rainmaking, anthropological theory] 相似文献
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Shivani V. Gandhi William Rodriguez Mansoor Khan James E. Polli 《AAPS PharmSciTech》2014,15(3):601-611
It has been advocated that biopharmaceutic risk assessment should be conducted early in pediatric product development and synchronized with the adult product development program. However, we are unaware of efforts to classify drugs into a Biopharmaceutics Classification System (BCS) framework for pediatric patients. The objective was to classify five drugs into a potential BCS. These five drugs were selected since both oral and intravenous pharmacokinetic data were available for each drug, and covered the four BCS classes in adults. Literature searches for each drug were conducted using Medline and applied to classify drugs with respect to solubility and permeability in pediatric subpopulations. Four pediatric subpopulations were considered: neonates, infants, children, and adolescents. Regarding solubility, dose numbers were calculated using a volume for each subpopulation based on body surface area (BSA) relative to 250 ml for a 1.73 m2 adult. Dose numbers spanned a range of values, depending upon the pediatric dose formula and subpopulation. Regarding permeability, pharmacokinetic literature data required assumptions and decisions about data collection. Using a devised pediatric BCS framework, there was agreement in adult and pediatric BCS class for two drugs, azithromycin (class 3) and ciprofloxacin (class 4). There was discordance for the three drugs that have high adult permeability since all pediatric permeabilities were low: dolasetron (class 3 in pediatric), ketoprofen (class 4 in pediatric), and voriconazole (class 4 in pediatric). A main contribution of this work is the identification of critical factors required for a pediatric BCS. 相似文献
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Alba Palacin-Arce Celia Monteagudo Juan de Dios Beas-Jimenez Fatima Olea-Serrano Miguel Mariscal-Arcas 《PloS one》2015,10(5)
BackgroundNumerous supplements are used by sportspeople. They are not always appropriate for the individual or the sports activity and may do more harm than good. Vitamin and mineral supplements are unnecessary if the energy intake is sufficient to maintain body weight and derives from a diet with an adequate variety of foods. The study objectives were to evaluate the main nutrients used as supplements in sports and to propose a nutritional quality index (NQI) that enables sportspeople to optimize their use of supplements and detect and remedy possible nutritional deficits.ResultsA superior mean NQI score was obtained when the supplements taken by participants were not included (16. 28 (SD of 3.52)) than when they were included (15.47 (SD: 3.08)), attributable to an excessive intake of some nutrients through supplementation.ConclusionsThese results indicate that sportspeople with a varied and balanced diet do not need supplements, which appear to offer no performance benefits and may pose a health risk. 相似文献
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Tiago Siebert Altavini Leonardo Dutra Henriques Daniela Maria Oliveira Bonci Balázs Vince Nagy Dora Fix Ventura Valdir Filgueiras Pessoa 《International journal of primatology》2012,33(6):1467-1476
The identification of color vision types in primates is fundamental to understanding the evolution and biological function of color perception. The Hard, Randy, and Rittler (HRR) pseudoisochromatic test categorizes human color vision types successfully. Here we provide an experimental setup to employ HRR in a nonhuman primate, the capuchin (Cebus libidinosus), a platyrrhine with polymorphic color vision. The HRR test consists of plates with a matrix composed of gray circles that vary in size and brightness. Differently colored circles form a geometric shape (X, O, or Δ) that is discriminated visually from the gray background pattern. The ability to identify these shapes determines the type of dyschromatopsy (deficiency in color vision). We tested six capuchins in their own cages under natural sunlight. The subjects chose between two HRR plates in each trial: one with the gray pattern only and the other with a colored shape, presented on the left or right side at random. We presented the test 40 times and calculated the 95?% confidence limits for chance performance based on the binomial test. We also genotyped all subjects for exons 3 and 5 of the X-linked opsin genes. The HRR test diagnosed two subjects as protan dichromats (missing or defective L-cone), three as deutan dichromats (missing or defective M-cone), and one female as trichromat. Genetic analysis supported the behavioral data for all subjects. These findings show that the HRR test can be applied to diagnose color vision in nonhuman primates. 相似文献
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