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Genetic Material (genetic + material)
Selected AbstractsLocal gene delivery to the vessel wallACTA PHYSIOLOGICA, Issue 1 2001R. C. Smith This review will provide an overview of delivery strategies that are being evaluated for vascular gene therapy. We will limit our discussion to those studies that have been demonstrated, utilizing in vivo model systems, to limit post-interventional restenosis. We also discuss the efficacy of the vectors and methods currently being used to transfer genetic material to the vessel wall. The efficiency of these techniques is a critical issue for the successful application of gene therapy. [source] Regulatory impact on insect biotechnology and pest managementENTOMOLOGICAL RESEARCH, Issue 4 2007Chris A. WOZNIAK Abstract The application of insect biotechnology is promising for the development of environmentally compatible pest management solutions. As we have refined and enhanced genetic engineering techniques in several insect species that cause significant economic loss and public health injury, it has become clear that insect biotechnology will move forward as one of the key tools of pest management in agriculture and in the human environment. Well characterized genetic elements can be manipulated toward specific aims and maintain a viable insect, albeit one with diminished capacity to exchange genetic material, vector a virus or bacterium, or complete its life cycle. Despite this degree of knowledge and precision, there remain unanswered questions regarding environmental fate, release and public acceptance of this technology. The uncertainty surrounding any novel technology inevitably increases the level of regulatory scrutiny associated with its use. Although the term "insect biotechnology" has many connotations, it certainly includes the genetic modification of symbiotic or commensally associated microbes as a means of delivering a trait (e.g. a toxin) to manage plant and human diseases and insect pests. The distinction between this paratransgenic approach and direct genetic modification of insect pests is an important one biologically as well as from a regulatory standpoint. The regulatory framework for microbial applications to agriculture is in many instances in place; however, we must strive to forge the development of guidelines and regulations that will foster deployment of insect biotechnologies. [source] Improved Comet assay for the assessment of UV genotoxicity in Mediterranean sea urchin eggsENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 5 2008Sarah Nahon Abstract Gametes and embryos of broadcast spawners are exposed to a wide range of chemical and physical stressors which may alone, or in conjunction, have serious consequences on reproductive outcomes. In this study, two Mediterranean echinoid species, Paracentrotus lividus and Sphaerechinus granularis, were chosen as models to study the genotoxicity of UV radiation (UVR) on the eggs of broadcast-spawning marine invertebrates. The single cell gel electrophoresis, or Comet assay, was successfully adapted to assess DNA strand breakage in sea urchin eggs. The results demonstrated that the genetic material of sea urchin eggs is susceptible to environmentally realistic UV exposure. The induction of DNA damage in the irradiated unfertilized eggs suggests that the previously described defense mechanisms in sea urchin eggs do not completely protect the egg's DNA against UV toxicity. Taken together, our results suggest that UV-impairment of the genetic integrity of the eggs might have a role in postfertilization failures and abnormal embryonic development. Although both species were vulnerable to UVR, embryonic development was less dramatically impaired in P.Lividus. This observation supports the postulation that species inhabiting shallower environments possess more efficient mechanisms to overcome UV-induced DNA alterations. The present demonstration of the utility and sensitivity of the Comet assay to evaluate DNA integrity in eggs from marine invertebrates opens new perspectives for monitoring the long-term effects of environmental exposure on populations and for the routine screening of substances for genotoxicity in marine systems. Environ. Mol. Mutagen., 2008. © 2008 Wiley-Liss, Inc. [source] POSTCOPULATORY FERTILIZATION BIAS AS A FORM OF CRYPTIC SEXUAL SELECTIONEVOLUTION, Issue 5 2008Ryan Calsbeek Males and females share most of their genetic material yet often experience very different selection pressures. Some traits that are adaptive when expressed in males may therefore be maladaptive when expressed in females. Recent studies demonstrating negative correlations in fitness between parents and their opposite-sex progeny suggest that natural selection may favor a reduction in trait correlations between the sexes to partially mitigate intralocus sexual conflict. We studied sex-specific forms of selection acting in Anolis lizards in the Greater Antilles, a group for which the importance of natural selection has been well documented in species-level diversification, but for which less is known about sexual selection. Using the brown anole (Anolis sagrei), we measured fitness-related variation in morphology (body size), and variation in two traits reflecting whole animal physiological condition: running endurance and immune function. Correlations between body size and physiological traits were opposite between males and females and the form of natural selection acting on physiological traits significantly differed between the sexes. Moreover, physiological traits in progeny were correlated with the body-size of their sires, but correlations were null or even negative between parents and their opposite-sex progeny. Although results based on phenotypic and genetic correlations, as well as the action of natural selection, suggest the potential for intralocus sexual conflict, females used sire body size as a cue to sort sperm for the production of either sons or daughters. Our results suggest that intralocus sexual conflict may be at least partly resolved through post-copulatory sperm choice in A. sagrei. [source] LEAKY PREZYGOTIC ISOLATION AND POROUS GENOMES: RAPID INTROGRESSION OF MATERNALLY INHERITED DNAEVOLUTION, Issue 4 2005Kai M. A. Chan Abstract Accurate phylogenies are crucial for understanding evolutionary processes, especially species diversification. It is commonly assumed that "good" species are sufficiently isolated genetically that gene genealogies represent accurate phylogenies. However, it is increasingly clear that good species may continue to exchange genetic material through hybridization (introgression). Many studies of closely related species reveal introgression of some genes without others, often with more rapid introgression of maternally inherited chloroplast or mitochondrial DNA (cpDNA, mtDNA). We seek a general explanation for this biased introgression using simple models of common reproductive isolating barriers (RIBs). We compare empirically informed models of prezygotic isolation (for pre- and postinsemination mechanisms of both female choice and male competition) with postzygotic isolation and demonstrate that rate of introgression depends critically upon type of RIB and mode of genetic inheritance (maternal versus biparental versus paternal). Our frequency-dependent prezygotic RIBs allow much more rapid introgression of biparentally and maternally inherited genes than do commonly modeled postzygotic RIBs (especially maternally inherited DNA). After considering the specific predictions in the context of empirical observations, we conclude that our model of prezygotic RIBs is a general explanation for biased introgression of maternally inherited genomic components. These findings suggest that we should use extreme caution when interpreting single gene genealogies as species phylogenies, especially for cpDNA and mtDNA. [source] Genome analysis of microorganisms living in amoebae reveals a melting pot of evolutionFEMS MICROBIOLOGY REVIEWS, Issue 3 2010Claire Moliner Abstract Amoebae-resistant microorganisms exhibit a specific lifestyle. Unlike allopatric specialized intracellular pathogens, they have not specialized because they infect the amoebae via amoebal attack and present a sympatric lifestyle with species from different phyla. In this review, we compare the genomes from bacteria (Legionella pneumophila, Legionella drancourtii, Candidatus,Protochlamydia amoebophila,'Rickettsia bellii, Candidatus,Amoebophilus asiaticus') and a virus (mimivirus) that multiply naturally in amoebae. The objective is to highlight the genomic traits characterizing these microorganisms and their niche by comparison with other specialized pathogens. The genome of intra-amoebal microorganisms is significantly larger than that of their relatives, contradicting the genome reduction theory mostly accepted for intracellular pathogens. This is probably due to the fact that they are not specialized and therefore maintain their genome size. Moreover, the presence of many horizontally transferred genes and mobilomes in their genomes suggests that these microorganisms acquired genetic material from their neighbors and amoebal host, thus increasing their genome size. Important features involved in gene transfer and pathogenicity were thus acquired. These characteristics suggest that amoebae constitute a gene melting pot, allowing diverse microorganisms to evolve by the same pathway characterized by gene acquisition, and then either adapt to the intra-amoebal lifestyle or create new pathogens. [source] From ancient genes to modern communities: the cellular stress response and the evolution of plant strategiesFUNCTIONAL ECOLOGY, Issue 5 2005S. PIERCE Summary 1Two major plant strategy theories attempt to explain how phenotype determines community structure. Crucially, CSR plant strategy theory suggests that stress and sporadic resource availability favour conservative phenotypes, whereas the resource-ratio hypothesis views the spatial heterogeneity of resources as selecting for optimal foraging in chronically unproductive habitats. Which view is most realistic? 2The ecophysiology literature demonstrates that stress is comprised of two processes: (1) limitation of resource supply to metabolism; and (2) damage to biomembranes, proteins and genetic material (chronic stress). Thus stress is defined mechanistically as the suboptimal performance of metabolism. 3Adaptations to limitation buffer metabolism against variability in external resource supply; internal storage pools are more consistent. Chronic stress elicits the same ancient cellular stress response in all cellular life: investment in stress metabolites that preserve the integrity and compartmentalization of metabolic components in concert with molecular damage-repair mechanisms. 4The cellular stress response was augmented by morphological innovations during the Silurian,Devonian terrestrial radiation, during which nutrient limitation appears to have been a principal selection pressure (sensu CSR theory). 5The modern stress,tolerator syndrome is conservative and supports metabolism in limiting or fluctuating environmental conditions: standing resource pools with high investment/maintenance costs impose high internal diffusion resistances and limit inherent growth rate (sensu CSR theory). 6The resource-ratio hypothesis cannot account for the cellular stress response or the crucial role of ombrotrophy in primary succession. CSR theory agrees with current understanding of the cellular stress response, terrestrial radiation and modern adaptations recorded in chronically unproductive habitats, and is applicable as CSR classification. [source] Paleosols in Central Illinois as Potential Sources of Ammonium in GroundwaterGROUND WATER MONITORING & REMEDIATION, Issue 4 2009Justin J. G. Glessner Glacially buried paleosols of pre-Holocene age were evaluated as potential sources for anomalously large concentrations of ammonium in groundwater in East Central Illinois. Ammonium has been detected at concentrations that are problematic to water treatment facilities (greater than 2.0 mg/L) in this region. Paleosols characterized for this study were of Quaternary age, specifically Robein Silt samples. Paleosol samples displayed significant capacity to both store and release ammonium through experiments measuring processes of sorption, ion exchange, and weathering. Bacteria and fungi within paleosols may significantly facilitate the leaching of ammonium into groundwater by the processes of assimilation and mineralization. Bacterial genetic material (DNA) was successfully extracted from the Robein Silt, purified, and amplified by polymerase chain reaction to produce 16S rRNA terminal restriction fragment length polymorphism (TRFLP) community analyses. The Robein Silt was found to have established diverse and viable bacterial communities. 16S rRNA TRFLP comparisons to well-known bacterial species yielded possible matches with facultative chemolithotrophs, cellulose consumers, nitrate reducers, and actinomycetes. It was concluded that the Robein Silt is both a source and reservoir for groundwater ammonium. Therefore, the occurrence of relatively large concentrations of ammonium in groundwater monitoring data may not necessarily be an indication of only anthropogenic contamination. The results of this study, however, need to be placed in a hydrological context to better understand whether paleosols can be a significant source of ammonium to drinking water supplies. [source] Development of a swine model of secondary liver tumor from a genetically induced swine fibroblast cell lineHPB, Issue 3 2008R. Abbas Abstract Aim. Metastatic disease is the most common liver tumor. Although alternative therapies have been developed for non-surgical candidates, those therapies lacked ideal testing prior to clinical application because of a paucity of large animal models. The purpose of the present study was to develop a model for secondary liver tumor in a large animal. Material and methods. Fibroblasts were isolated from swine ear lobules and then transfected with amphotrophic retroviruses encoding human or murine genetic material (hTERT, p53DD, cyclinD-1, CDK4R24C, Myc T58A, RasG12V). Transformed cell lines were finally inoculated subcutaneously (s.c.) into: 1) immunodeficient mice (nude), 2) immunocompetent mice (wild type), 3) immunosuppressed swine (under tacrolimus or corticosteroids), 4) immunocompetent swine, and 5) into the liver and portal circulation of swine under steroid-based immunosuppression. Results. In the murine model, tumor growth was evident in 100% of the nude mice (n=5), with a peak size of 20 mm (15.22±4.5 mm; mean±SD) at the time of sacrifice (3 weeks). Tumor growth was evident in 71% of the wild mice (n=21), with a peak size of 7.8 mm (4.19±1.1 mm) by the third week of growth. In the swine model, tumor growth was evident in 75% (3/4 ears; n=2) of swine under tacrolimus-based immunosuppression versus 50% of swine under steroids-based immunosuppression (n=2). Tumor growth was slow in two animals, while in one animal the tumor was larger with a peak growth of 42 mm at 3 weeks. The tumor pattern in the ear lobules was characterized by slow growth, with a peak size of 6,8 mm in the immunocompetent swine at 3 weeks. All tumors were shown to be malignant by histology. In contrast, inoculums of the transformed fibroblast cell line in swine livers showed no evidence of tumor growth at 3 weeks. Conclusions. Development of a transformed swine fibroblast cell line was successful, resulting in an in vivo malignant tumor. Cell line inoculums had tumorigenic properties in nude mice, wild-type mice, and immunosuppressed swine, as judged by uncontrolled cell growth, invasion of surrounding tissue, neoangiogenesis, and invasion of normal vasculature, resulting in the formation of tumor nodules. Such properties were not observed in swine upon inoculation into the liver/portal circulation. [source] Effect of natural commensal-origin DNA on toll-like receptor 9 (TLR9) signaling cascade, chemokine IL-8 expression, and barrier integritiy of polarized intestinal epithelial cellsINFLAMMATORY BOWEL DISEASES, Issue 3 2010Darab Ghadimi Abstract Background and Aim: The intestinal epithelium is constantly exposed to high levels of genetic material like bacterial DNA. Under normal physiological conditions, the intestinal epithelial monolayer as a formidable dynamic barrier with a high-polarity structure facilitates only a controlled and selective flux on components between the lumen and the underlining mucosa and even is able to facilitate structure-based macromolecules movement. The aim of this study was to test the effect of natural commensal-origin DNA on the TLR9 signaling cascade and the barrier integrity of polarized intestinal epithelial cells (IECs). Methods: Polarized HT-29 and T84 cells were treated with TNF-, in the presence or absence of DNA from Lactobacillus rhamnosus GG (LGG) and Bifidobacterium longum. TLR9 and interleukin-8 (IL-8) mRNA expression was assessed by semiquantitative and TaqMan real-time reverse-transcription polymerase chain reaction. Expression of TLR9 protein, degradation of inhibitor of kappa B alpha (I,B,), and p38 mitogen-activated protein kinase (p38 MAP) phosphorylation were assessed by Western blotting. To further reveal the role of TLR9 signaling, the TLR9 gene was silenced by siRNA. IL-8 secretion was measured by an enzyme-linked immunosorbent assay. Nuclear factor-kappa B (NF-,B) activity was assessed by the electrophoretic mobility shift assay (EMSA) and NF-,B-dependent luciferase reporter gene assays. As an indicator of tight junction formation and monolayer integrity of epithelial cell monolayers, transepithelial electrical resistance (TER) was repetitively monitored. Transmonolayer movement of natural commensal-origin DNA across monolayers was monitored using qRT-PCR and nested PCR based on bacterial 16S rRNA genes. Results: In response to apically applied natural commensal-origin DNA, polarized HT-29 and T84 cells enhanced expression of TLR9 in a specific manner, which was subsequently associated with attenuation of TNF-,-induced NF-,B activation and NF-,B-mediated IL-8 expression. TLR9 silencing abolished this inhibitory effect. Apically applied LGG DNA attenuated TNF-,-enhanced NF-,B activity by reducing I,B, degradation and p38 phosphorylation. LGG DNA did not decrease the TER but rather diminished the TNF-,-induced TER reduction. Translocation of natural commensal-origin DNA into basolateral compartments did not occur under tested conditions. Conclusions: Our study indicates that TLR9 signaling mediates, at least in part, the anti-inflammatory effects of natural commensal-origin DNA on the gut because TLR9 silencing abolished the inhibitory effect of natural commensal-origin DNA on TNF-,-induced IL-8 secretion in polarized IECs. The nature of the TLR9 agonist, the polarity of cells, and the tight junction integrity of IECs has to be taken into account in order to predict the outcome of TLR9 signaling. (Inflamm Bowel Dis 2010) [source] Consumer attitudes and acceptance of genetically modified organisms in KoreaINTERNATIONAL JOURNAL OF CONSUMER STUDIES, Issue 3 2003Hyochung Kim Genetically modified organisms (GMOs) were first used to designate micro organisms that had had genes from other species transferred into their genetic material by the then-new techniques of ,gene-splicing.' Cultivation of GMOs has so far been most widespread in the production of soybeans and maize. The United States holds almost three-fourths of the total crop area devoted to GMOs. Because many crops have been imported from the US, there is a large possibility for consumers to intake the products of GMOs in Korea. The safety of GMOs is not scientifically settled at this time, however. Additionally, the research regarding the GMOs issue of consumers has rarely been conducted in Korea. This study therefore focused on the consumer attitudes about GMOs and willingness to purchase them. The data were collected from 506 adults living in Seoul, Daegu and Busan, Korea, by means of a self-administered questionnaire. Frequencies and chi-square tests were conducted by SPSS. The results of the survey were as follows. First, the consumer concerns about GMOs were high but recognition was low; many respondents answered they did not have exact information about GMOs, although they had heard about them. Second, almost 93% of the respondents desired the labelling of GMOs. Third, the level of acceptance of GMOs was high; two-thirds of the respondents showed that they were willing to buy GMOs. Finally, many respondents worried about the safety of GMOs in that 73% of the respondents primarily wanted to be informed about safety of GMOs. This study suggests that the consumer education about GMOs should be conducted through mass media and consumer protection organisations. [source] Nuclear localization signals and human diseaseIUBMB LIFE, Issue 7 2009Laura M. McLane Abstract In eukaryotic cells, the physical separation of the genetic material in the nucleus from the translation and signaling machinery in the cytoplasm by the nuclear envelope creates a requirement for a mechanism through which macromolecules can enter or exit the nucleus as necessary. Nucleocytoplasmic transport involves the specific recognition of cargo molecules by transport receptors in one compartment followed by the physical relocation of that cargo into the other compartment through regulated pores that perforate the nuclear envelope. The recognition of protein cargoes by their transport receptors occurs via amino acid sequences in cargo proteins called nuclear targeting signals. Both nuclear import and export of proteins are highly regulated processes that control, not only what cargo can enter and/or exit the nucleus, but also when in the cell cycle and in what cell type, the cargo can be transported. Deregulation of the nuclear transport of specific cargoes has been linked to numerous cancers and developmental disorders highlighting the importance of understanding the mechanisms underlying nucleocytoplasmic transport and particularly the modulation of the specific interactions between transporter receptors and nuclear targeting signals within target cargo proteins. © 2009 IUBMB IUBMB Life 61(7): 697,706, 2009 [source] Does animal breeding and conservation need new regulations for the exchange and use of genetic material?JOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 6 2006Sipke J. Hiemstra No abstract is available for this article. [source] Adult-derived stem cells and their potential for use in tissue repair and molecular medicineJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2005Henry E. Young Abstract This report reviews three categories of precursor cells present within adults. The first category of precursor cell, the epiblast-like stem cell, has the potential of forming cells from all three embryonic germ layer lineages, e.g., ectoderm, mesoderm, and endoderm. The second category of precursor cell, the germ layer lineage stem cell, consists of three separate cells. Each of the three cells is committed to form cells limited to a specific embryonic germ layer lineage. Thus the second category consists of germ layer lineage ectodermal stem cells, germ layer lineage mesodermal stem cells, and germ layer lineage endodermal stem cells. The third category of precursor cells, progenitor cells, contains a multitude of cells. These cells are committed to form specific cell and tissue types and are the immediate precursors to the differentiated cells and tissues of the adult. The three categories of precursor cells can be readily isolated from adult tissues. They can be distinguished from each other based on their size, growth in cell culture, expressed genes, cell surface markers, and potential for differentiation. This report also discusses new findings. These findings include the karyotypic analysis of germ layer lineage stem cells; the appearance of dopaminergic neurons after implantation of naive adult pluripotent stem cells into a 6-hydroxydopamine-lesioned Parkinson's model; and the use of adult stem cells as transport mechanisms for exogenous genetic material. We conclude by discussing the potential roles of adult-derived precursor cells as building blocks for tissue repair and as delivery vehicles for molecular medicine. [source] Herpetic Folliculitis is Usually a Consequence of Varicella Zoster Virus InfectionJOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2005J Blair Skin biopsies of 8 patients diagnosed with herpetic folliculitis by light microscopy were retrieved from the files of the UCSF Dermatopathology Service. Clinical and microscopical features were reviewed and tabulated, and PCR analysis was employed to seek DNA sequences specific for herpes simplex virus (HSV) and varicella zoster virus (VZV). The study group included 4 women and 4 men, ages 15 to 54. Five patients (62%) were immunosuppressed, with underlying conditions including HIV infection, leukemia, rheumatoid arthritis, and lupus erythematosus with polyarteritis nodosa. Microscopically, herpetic cytopathic changes involved the isthmus in 7/8 cases (87%), and involved the sebaceous apparatus in 4/8 cases (50%). Herpetic viropathic changes were not found within eccrine epithelium. A moderate to dense perifollicular infiltrate, comprised mostly of lymphocytes, was evident in 7/8 cases (87%). After PCR expansion of genetic material extracted from the original paraffin blocks, VZV-specific DNA sequences were detected in 8/8 cases. We conclude that herpetic folliculitis is a consequence of VZV infection. Because follicular herpetic infection is often accompanied by a dense perifollicular lymphoid infiltrate, the microscopical presentation can simulate inflammatory skin diseases such as lupus erythematosus. Level sections may be required for a specific diagnosis to be made. [source] Molted feathers from clay licks in Peru provide DNA for three large macaws (Ara ararauna, A. chloropterus, and A. macao)JOURNAL OF FIELD ORNITHOLOGY, Issue 2 2009Kara J. Gebhardt ABSTRACT Conservation genetic analyses of wildlife have increased greatly in the past 10 yr, yet genetic studies of parrots are rare because of difficulties associated with capturing them and obtaining samples. Recent studies have demonstrated that molted feathers can provide a useful source of DNA, but success rates have varied considerably among studies. Our objective was to determine if molted macaw feathers from Blue-and-yellow Macaws (Ara ararauna), Scarlet Macaws (A. macao), and Red-and-green Macaws (A. chloropterus) collected from rainforest geophagy sites called clay licks could provide a good source of DNA for population genetic studies. Specific objectives were to determine (1) how nuclear DNA microsatellite amplification success and genotyping error rates for plucked macaw feathers compared to those for molted feathers collected from clay licks in the Amazon rainforest, and (2) if feather size, feather condition, species, or extraction method affected microsatellite amplification success or genotyping error rates from molted feathers. Amplification success and error rates were calculated using duplicate analyses of four microsatellite loci. We found that plucked feathers were an excellent source of DNA, with significantly higher success rates (P < 0.0001) and lower error rates (P= 0.0002) than for molted feathers. However, relatively high success rates (75.6%) were obtained for molted feathers, with a genotyping error rate of 11.7%. For molted feathers, we had higher success rates and lower error rates for large feathers than small feathers and for feathers in good condition than feathers that were moldy and broken when collected. We also found that longer incubation times and lower elution volumes yielded the highest quality DNA when extracting with the Qiagen DNeasy tissue kit. Our study demonstrates that molted feathers can be a valuable source of genetic material even in the challenging conditions of tropical rainforests, and our results provide valuable information for maximizing DNA amplification success rates when working with shed feathers of parrots. SINOPSIS Los análisis genéticos para la conservación de la vida silvestre han crecido en gran escala durante los últimos 10 años, pero el análisis genético de los loros son raros por las dificultades asociados con su captura y obtención de muestras. Estudios recientes han demostrado que plumas mudadas podrían proveer una fuente útil de ADN, pero las tasas de éxito varían considerablemente entre estudios. Nuestro objetivo fue determinar si las plumas mudadas de Ara ararauna, A. macao y A. chloropterus colectadas en sitios de bosque húmedo donde estas aves consumen el suelo, llamados colpas, podrían proveer una fuente útil de ADN para estudios de la genética de las poblaciones. Los objetivos específicos fueron determinar (1) como comparan las tasas de éxito de la amplificación de los microsatélites del ADN nuclear y las tasas de error en el análisis del genotipo de plumas, entre plumas colectadas directamente de los guacamayos y plumas colectadas en colpas en el bosque Amazónico, y (2) si el tamaño de la pluma, su condición, la especie o el método de extracción afecta el éxito de la amplificación de los microsatélites o las tasas de error en el análisis del genotipo de las plumas mudadas. Las tasas de éxito de amplificación y error fueron calculados usando análisis duplicados de cuatro loci de microsatélites. Encontramos que plumas colectadas directamente de las aves son una fuente excelente de ADN, con tasas de éxito significativamente más altas (P < 0.0001), y con menores tasas de error (P= 0.0002) que las plumas mudadas. Sin embargo, tasas de éxito relativamente altas (75.6%) fueron obtenidos de plumas mudadas, con una tasa de error en el análisis del genotipo de 11.7%. Para plumas mudadas, tuvimos tasas de éxito más altas y tasas de error menores para plumas grandes que para plumas pequeñas y para plumas en buena condición que para plumas que estaban cubiertos con hongos y quebradas cuando fueron colectadas. También encontramos que mayores periodos de incubación y menores volúmenes de elución proveían el ADN de mayor calidad cuando se extraía el ADN usando el kit de tejido Quiagen DNeasy. Nuestro estudio demuestra que las plumas mudadas pueden ser una fuente valiosa de materia genética, hasta en las condiciones de los bosques húmedos tropicales. Nuestros resultados proveen información valiosa para maximizar las tasas de éxito de la amplificación del ADN cuando se analizan las plumas mudadas de los loros. [source] Differential defoliation of Eucalyptus grandis arises from indiscriminant oviposition and differential larval survivalAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 1 2009M. L. Henery Abstract 1,The influence of six open-pollinated families (OPFs) of Eucalyptus grandis on both the growth and development of larvae and the oviposition preference of a paropsine chrysomelid (Paropsis atomaria) was investigated. The OPFs had previously been identified as differing in their susceptibility to defoliation by P. atomaria in forestry progeny trials. 2,Oviposition preference for resistant and susceptible foliage was tested using binary choice tests. These tests did not demonstrate any significant preference for either resistant or susceptible open-pollinated material indicating that adult host preference for susceptible trees was not a likely cause of differential defoliation. 3,Quantification and analysis of growth and development parameters for all larval stages of P. atomaria showed that feeding on genetic material identified as resistant resulted in a significant reduction of relative growth rate of first instar larvae and an alteration to normal feeding behaviour. There was also a trend towards increased larval mortality on resistant E. grandis. 4,We argue that although the magnitude of these effects was minor, interactions with additional biotic and abiotic sources of mortality in the field have the potential, when magnified over successive generations, to result in significant variation in defoliation of host genotypes in the field. [source] Poly(glycoamidoamine)s: Cationic glycopolymers for DNA deliveryJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 24 2006Theresa M. Reineke Abstract Polymer science is playing an exciting role in inspiring and advancing novel discoveries in the area of genetic drug delivery. Polymeric materials can be synthesized and chemically tailored to bind and compact nucleic acids into viral-like nanoparticles termed polyplexes that can deliver genetic materials into cells. This article highlights our work in this area to synthesize and study a novel class of cationic glycopolymers that we have termed poly(glycoamidoamine)s (PGAAs). The design of these materials has been inspired by many previous works in the literature. Carbohydrate comonomers have been incorporated into these structures to lower the toxicity of the delivery vehicle, and oligoamine moieties have been added to yield a cationic backbone that facilitates strong DNA binding, compaction, cellular uptake, and delivery of genetic material. PGAAs have been designed to vary in the carbohydrate size, the hydroxyl number and stereochemistry, the amine number, and the presence or absence of heterocyclic groups. Through structure,bioactivity studies, we have discovered that these materials are highly biocompatible, and each specific feature plays a large role in the observed delivery efficacy. Such structure,property studies are important for increasing our understanding of how the polymer chemistry affects the biological activity for the clinical development of polymer-based therapeutics. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6895,6908, 2006 [source] Review article: gene therapy, recent developments and future prospects in gastrointestinal oncologyALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 8 2010Y. Touchefeu Aliment Pharmacol Ther 2010; 32: 953,968 Summary Background, Gene therapy consists of the introduction of genetic material into cells for a therapeutic purpose. A wide range of gene therapy vectors have been developed and used for applications in gastrointestinal oncology. Aim, To review recent developments and published clinical trials concerning the application of gene therapy in the treatment of liver, colon and pancreatic cancers. Methods, Search of the literature published in English using the PubMed database. Results, A large variety of therapeutic genes are under investigation, such as tumour suppressor, suicide, antiangiogenesis, inflammatory cytokine and micro-RNA genes. Recent progress concerns new vectors, such as oncolytic viruses, and the synergy between viral gene therapy, chemotherapy and radiation therapy. As evidence of these basic developments, recently published phase I and II clinical trials, using both single agents and combination strategies, in adjuvant or advanced disease settings, have shown encouraging results and good safety records. Conclusions, Cancer gene therapy is not yet indicated in clinical practice. However, basic and clinical advances have been reported and gene therapy is a promising, new therapeutic approach for the treatment of gastrointestinal tumours. [source] Breeding of Pleurotus florida (oyster mushroom) for phenotypic pigmentation and high yield potentialJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2008Jatinder Kaur Abstract BACKGROUND: Cross-hybridisation is a technique for exchange of genetic material between two compatible nuclei to develop a recombinant genome with a probable expression for a desirable trait. This technique as an example of classical genetics has been applied in a heterothallic bifactorial/tetrapolar fungus Pleurotus florida. It has worked successfully during this study in a small number of experiments. RESULTS: Fruit bodies from the Pleurotus florida PAU-5 were allowed to shed their basidiospores on filter paper under aseptic conditions. Forty-nine monokaryons were isolated from three spore prints, namely Ja, Jb and K. Three hundred and fifty-six crosses were laid to result in five compatible reactions (PFJ4, PFJ9, PFJ11, PFJ13 and PFJ14). The fruit bodies of the hybrid dikaryon PFJ4 were found to show grey pigmentation. The hybrid dikaryons PFJ11 and PFJ14 grew faster in wheat straw substrate to take 39 and 41 days, respectively, for complete mycelial impregnation as compared to the parent, PAU-5 (48 days). The dikaryon PFJ11 out-yielded the parent by giving 34.2% biological efficiency compared to 29.8% for the parent. CONCLUSION: Through cross-hybridisation various changes at the genetic level are possible, showing altered phenotypic expression of the characters, such as change in fruiting efficiency and variability in fruit body characteristics (e.g., pileus shape and pigmentation). This technique can also be applied to other crops to improve their yield potential and bring about desirable phenotypic changes. Copyright © 2008 Society of Chemical Industry [source] Genetic variability: The key problem in the prevention and therapy of RNA-based virus infectionsMEDICINAL RESEARCH REVIEWS, Issue 4 2003Magdalena Figlerowicz Abstract Despite extraordinary progress that has recently been made in biomedical sciences, viral infectious diseases still remain one of the most serious world health problems. Among the different types of viruses, those using RNA as their genetic material (RNA viruses and retroviruses) are especially dangerous. At present there is no medicine allowing an effective treatment of RNA-based virus infections. Many RNA viruses and retroviruses need only a few weeks to escape immune response or to produce drug-resistant mutants. This seems to be the obvious consequence of the unusual genetic variability of RNA-based viruses. An individual virus does not form a homogenous population but rather a set of similar but not identical variants. In consequence, RNA-based viruses can easily adapt to environmental changes, also those resulting from immune system response or therapy. The modifications identified within viral genes can be divided into two groups: point mutations and complex genome rearrangements. The former arises mainly during error-prone replication, whereas RNA recombination and generic reassortment are responsible for the latter. This article shortly describes major strategies used to control virus infections. Then, it presents the various mechanisms generating the genetic diversity of RNA-based viruses, which are most probably the main cause of clinical problems. © 2003 Wiley Periodicals, Inc. Med Res Rev, 23, No. 4, 488,518, 2003 [source] Thymineless death is associated with loss of essential genetic information from the replication originMOLECULAR MICROBIOLOGY, Issue 6 2010Dipen P. Sangurdekar Summary Thymine starvation results in a terminal cellular condition known as thymineless death (TLD), which is the basis of action for several common antibiotics and anticancer drugs. We characterized the onset and progression of TLD in Escherichia coli and found that DNA damage is the only salient property that distinguishes cells irreversibly senesced under thymine starvation from cells reversibly arrested by the nucleotide limitation. The damage is manifested as the relative loss of genetic material spreading outward from the replication origin: the extent of TLD correlates with the progression of damage. The reduced lethality in mutants deficient in the RecFOR/JQ repair pathway also correlates with the extent of damage, which explains most of the observed variance in cell killing. We propose that such spatially localized and persistent DNA damage is the consequence of transcription-dependent initiation of replication in the thymine-starved cells and may be the underlying cause of TLD. [source] Polyploidy in atypical grade II choroid plexus papilloma of the posterior fossaNEUROPATHOLOGY, Issue 3 2009María Sol Brassesco Cytogenetic studies of choroid plexus tumors, particularly for atypical choroid plexus papillomas, have been rarely described. In the present report, the cytogenetic investigation of an atypical choroid plexus papilloma occurring at the posterior fossa of a 16-year-old male is described. Comparative genome hybridization analysis demonstrated gains of genetic material from almost all chromosomes. Chromosome losses involved 19p, regional losses at chromosome X and loss of chromosome Y. The presence of polyploid cells was confirmed by fluorescence in situ hybridization analysis with probes directed to centromeric regions. Furthermore, the microscopic analysis of cultures showed nuclear buds, nucleoplasmic bridges, and micronuclei in 23% of tumor cells suggesting the presence of complex chromosomal abnormalities. Previous cytogenetic studies on choroid plexus papillomas showed either normal, hypodiploid or hyperdiploid karyotypes. To the best of our knowledge, this is the first report of polyploidy in choroid plexus papilloma of intermediate malignancy grade. Although the mechanisms beneath such genome duplication remain to be elucidated, the observed abnormal nuclear shapes indicate constant restructuring of the tumor's genome and deserves further investigation. [source] The ethics of reusing archived tissue for researchNEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 5 2000R. Ashcroft Pathologists have been establishing archives of human organs and tissue for research use for many years now. Controversy has arisen recently over these collections, particularly with regard to the right of patients or relatives to consent to removal and retention of tissue, genetic research using stored tissue samples, and commercial exploitation of tissue collections and genetic material. This paper discusses the ethics of reusing existing archives of tissue. New archives are established under much more stringent conditions than in the past. What rules should apply to existing archives? Guidelines to regulate such use are useful, but face serious difficulties in balancing the variety of public and private interests relating to tissue banking. Consent cannot be obtained retrospectively, but public trust can be established by open acknowledgement of the evolution of ethical standards and strict adherence to current best practice. Guidelines and standards vary from country to country, but ethical principles should not. The implications of this view for pathologists worldwide are discussed. [source] Technical aspects and clinical applications of measuring BCR-ABL1 transcripts number in chronic myeloid leukemia,AMERICAN JOURNAL OF HEMATOLOGY, Issue 8 2009Letizia Foroni Chronic myeloid leukemia (CML) is a myeloproliferative disorder characterized by a triphasic clinical course, the morphologic expansion of a terminally differentiated myeloid cell and the presence of the BCR-ABL1 fusion gene, the hallmark of CML. The fusion gene is usually, but not always, associated with a Philadelphia chromosome, the result of a reciprocal exchange of genetic material between chromosome 22 and chromosome 9, which leads to the production of the activated BCR-ABL1 gene and oncoprotein. The breakpoint in the BCR gene occurs commonly downstream of exons e13 or e14 (M-BCR) and less frequently downstream of exons e1 and e2 (m- BCR). Less than 1% of cases carry a breakpoint downstream of exon 6 or 8 ("variant fusion genes") or exon 19 (,- BCR). Breakpoints in the ABL1 gene cluster upstream of exon a2 (or of exon a3 in less than 5% of patients with CML). Conventional cytogenetic, fluorescence in situ hybridization, and molecular testing for the BCR-ABL1 fusion gene are key investigations for the diagnosis and monitoring of CML. Treatment using tyrosine kinase inhibitors has revolutionized the management of CML with hematologic and cytogenetic response within 12,18 months observed in >85% of patients. Nevertheless, between 15 and 20% of patients may evolve to blastic phase. Measurement of low level or "minimal" residual disease using molecular tests is becoming the gold-standard approach to measure response to therapy due to its higher sensitivity compared to other routine techniques. The technical aspects and clinical applications of molecular monitoring will be the main focus of this article. Am. J. Hematol., 2009. © 2009 Wiley-Liss, Inc. [source] Mutagenic and antimutagenic potential of the medicinal plants M. laevigata and C. xanthocarpaPHYTOTHERAPY RESEARCH, Issue 3 2003J. B. F. Fernandes Abstract Aqueous extracts of medicinal plants (Mikania laevigata and Campomanesia xanthocarpa) were screened for the presence of mutagenic activity in the Salmonella/microsome assay. The extracts of Campomanesia xanthocarpa showed frameshift (TA97a strain) signs of mutagenic activity without exogenous metabolism (S9 fraction). The infusions of Mikania laevigata, negative for mutagenic activity, showed high percentages of inhibition of mutagenesis induced by mutagens 2AF (2-amino,uorene), in the presence of exogenous metabolism (S9 fraction), for frameshift (TA98) and base pair substitution (TA100) lesions. In addition, these inhibitions were observed against mutagen SAZ (sodium azide) in assays with the TA100 strain, without exogenous metabolism (S9 fraction). A synergistic effect was also observed in frameshift mutagenic events, with direct action in the presence of 4NQO (4-oxide-1-nitroquinoline) and a tendency to a low percentage of action enhancement, in the presence of the 2AF mutagen. The variable responses observed in the extract assays show the potentials for interaction of the different active principles in genetic material. Copyright © 2003 John Wiley & Sons, Ltd. [source] Frizzled-1 is down-regulated in follicular thyroid tumours and modulates growth and invasiveness,THE JOURNAL OF PATHOLOGY, Issue 1 2008A Ulivieri Abstract The mechanisms of follicular thyroid carcinoma (FTC) transformation and progression are not well understood. Previously, we detected LOH at 7q21 in all FTCs examined, indicating that loss of genetic material in that region is a common trait in these lesions. To analyse the effects of LOH on gene expression, we performed an analysis of the mRNA expression levels of six different genes, located at 7q21.1,7q21.3. A total of 23 lesions, including eight follicular hyperplasias (FHs), eight follicular adenomas (FAs), two FTCs and five papillary thyroid carcinomas (PTCs) were analysed. The Frizzled-1 (FZD-1) gene, located at 7q21.13, showed the lowest levels of mRNA expression. Down-regulation of FZD-1 expression was also confirmed in an independent series of 69 follicular neoplastic lesions compared to 25 PTCs, analysed by quantitative RT,PCR. In vitro studies showed that FZD-1 expression was also markedly reduced at both protein and mRNA levels in three FTC-derived cell lines (FRO, WRO and FTC-133), while it was normal in the three PTC-derived cell lines (Ca300, Ca301 and K1) examined. We demonstrated that over-expression of FZD-1 in 3 FTC-derived cells decreased invasiveness and proliferation rate, indicating a possible pathogenetic role. In addition, FZD-1 RNA interference in the PTC-derived cell line K1 increased invasiveness. Our data indicated that FZD-1 is involved in growth of follicular tumours and may be considered as a novel marker of this type of tumour. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source] Access to and Legal Protection of Aquaculture Genetic Resources,Norwegian PerspectivesTHE JOURNAL OF WORLD INTELLECTUAL PROPERTY, Issue 4 2006G. Kristin Rosendal A central socio-economic challenge in fish breeding arises from issues relating to access to and exclusive rights of genetic resources. Breeding companies need legal or biological protection measures to assure revenues from genetic improvement and investment in genetic material. Fish farmers and fish breeders need access to genetic resources for food production and further development and sustainable use of fish genetic material. How can a balance be created between the need for unencumbered and free access, on the one hand, and, on the other hand, the need to ensure a right to the results from breeding and research? First, we provide a brief outline of the rationale for ensuring access to and for using legal measures for protection of breeding materials in aquaculture. Secondly, we examine how technological developments and biological features present options and barriers that will affect choices relating to access and property right issues to fish genetic resources. [source] Elements for Legislation in User Countries to Meet the Fair and Equitable Benefit-Sharing CommitmentTHE JOURNAL OF WORLD INTELLECTUAL PROPERTY, Issue 2 2006Morten Walløe Tvedt The third objective of the Convention on the Biological Diversity, the fair and equitable benifit sharing of the use of genetic resources, is lagging behind at the implementation phase. Very few countries have taken effective measures to promote sharing of benefits arising from the use of genetic resources. This article offers some suggestions as to why this is the case and poses a number of questions that need to be dealt with before such a system can be in place. It develops the concept of genetic resources and suggests that the focus need to be at the successful end uses of genetic material rather than at the point in time when genetic material is found in the nature. [source] Gene Transfer in Human Vestibular Epithelia and the Prospects for Inner Ear Gene Therapy,,THE LARYNGOSCOPE, Issue 5 2008Bradley W. Kesser MD Abstract Transfer of exogenous genetic material into the mammalian inner ear using viral vectors has been characterized over the last decade. A number of different viral vectors have been shown to transfect the varying cell types of the nonprimate mammalian inner ear. Several routes of delivery have been identified for introduction of vectors into the inner ear while minimizing injury to existing structures and at the same time ensuring widespread distribution of the agent throughout the cochlea and the rest of the inner ear. These studies raise the possibility that gene transfer may be developed as a potential strategy for treating inner ear dysfunction in humans. Furthermore, a recent report showing successful transfection of excised human vestibular epithelia offers proof of principle that viralgene transfer is a viable strategy for introduction andexpression of exogenous genetic material to restore function to the inner ear. Human vestibular epithelia were harvested from patients undergoing labyrinthectomy, either for intractable Ménière's disease or vestibular schwannoma resection, and cultured for as long as 5 days. In those experiments, recombinant, multiply-deleted, replication-deficient adenoviral vectors were used to transfect and express a reporter gene as well as the functionally relevant gene, wild-type KCNQ4, a potassium channel gene that when mutated causes the autosomal dominant HL DFNA2. Here, we review the current state of viral-mediated gene transfer in the inner ear and discuss different viral vectors, routes of delivery, and potential applications of gene therapy. Emphasis is placed on experiments demonstrating viral transfection of human inner ear tissue and implications of these findings and for the future of gene therapy in the human inner ear. [source] | ||||||||||||||||||||||