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排序方式: 共有634条查询结果,搜索用时 31 毫秒
111.
112.
Maria Antonietta Germanà Benedetta Chiancone Sofiene B. M. Hammami Hava F. Rapoport 《Plant Cell, Tissue and Organ Culture》2014,118(3):409-417
The in vitro germination of excised embryos can break dormancy rapidly and shorten the time required to produce seedlings, speeding up olive breeding programmes as well as rootstock production. In this study, the in vitro germination potential of four Sicilian olive cultivars was evaluated during two years of experiments, using explants with three different morphological configurations that represent three different degrees of embryo exposure: (1) intact stoneless seeds containing the embryo, the endosperm and the seed coat (Emb+En+SC), (2) seeds without the seed coat (Emb+En) and (3) naked, isolated embryos (seed coat and endosperm both removed: Emb). Differences were found in the germination percentages and timing due to both genotype and explant type. The root and shoot meristems, the radicle-hypocotyl axis, the provascular tissues and embryo storage reserves were identified as embryo anatomical structures which could influence germination capacity. Observation of these structures, however, indicated similar germination potential among cultivars, suggesting possible differences in other dormancy factors. In spite of variation in cultivar performance, after 60 days of in vitro culture all cultivars demonstrated the highest germination of naked embryos (explant type 3) and lowest for stoneless seeds (explant type 1); stoneless seeds without the seedcoat (explant type 2) showed intermediate germination percentages. 相似文献
113.
Wilson C Venditti R Rega LR Colanzi A D'Angelo G De Matteis MA 《The Biochemical journal》2011,433(1):1-9
Remarkable advances have been made during the last few decades in defining the organizational principles of the secretory pathway. The Golgi complex in particular has attracted special attention due to its central position in the pathway, as well as for its fascinating and complex structure. Analytical studies of this organelle have produced significant advances in our understanding of its function, although some aspects still seem to elude our comprehension. In more recent years a level of complexity surrounding this organelle has emerged with the discovery that the Golgi complex is involved in cellular processes other than the 'classical' trafficking and biosynthetic pathways. The resulting picture is that the Golgi complex can be considered as a cellular headquarters where cargo sorting/processing, basic metabolism, signalling and cell-fate decisional processes converge. 相似文献
114.
Gentile MA Melchiorre S Emolo C Moschioni M Gianfaldoni C Pancotto L Ferlenghi I Scarselli M Pansegrau W Veggi D Merola M Cantini F Ruggiero P Banci L Masignani V 《The Journal of biological chemistry》2011,286(16):14588-14597
Streptococcus pneumoniae expresses on its surface adhesive pili, involved in bacterial attachment to epithelial cells and virulence. The pneumococcal pilus is composed of three proteins, RrgA, RrgB, and RrgC, each stabilized by intramolecular isopeptide bonds and covalently polymerized by means of intermolecular isopeptide bonds to form an extended fiber. RrgB is the pilus scaffold subunit and is protective in vivo in mouse models of sepsis and pneumonia, thus representing a potential vaccine candidate. The crystal structure of a major RrgB C-terminal portion featured an organization into three independently folded protein domains (D2-D4), whereas the N-terminal D1 domain (D1) remained unsolved. We have tested the four single recombinant RrgB domains in active and passive immunization studies and show that D1 is the most effective, providing a level of protection comparable with that of the full-length protein. To elucidate the structural features of D1, we solved the solution structure of the recombinant domain by NMR spectroscopy. The spectra analysis revealed that D1 has many flexible regions, does not contain any intramolecular isopeptide bond, and shares with the other domains an Ig-like fold. In addition, we demonstrated, by site-directed mutagenesis and complementation in S. pneumoniae, that the D1 domain contains the Lys residue (Lys-183) involved in the formation of the intermolecular isopeptide bonds and pilus polymerization. Finally, we present a model of the RrgB protein architecture along with the mapping of two surface-exposed linear epitopes recognized by protective antisera. 相似文献
115.
Birth cohort studies are important tools for life-course epidemiology, given the spectrum of the environmental, behavioural, and genetic factors that should be considered when making judgements on human health. Biobanks are valuable components of studies designed to investigate the genetic variability of diseases and improve phenotypic characterisation. In studies involving vulnerable populations and biobanks, it is essential to provide ethical reasoning and analyse the legal requirements. We describe the processes and the tools used in the iterative design of an appropriate informed consent model and the ethico-legal framework of the Piccolipiù study. The Piccolipiù study is a prospective population-based study funded by the Italian Ministry of Health that intends to enrol 3,000 newborns and their mothers in five Italian cities, and to store biological samples for future use. To realise these objectives, we performed a thorough evaluation of the literature, of national and international guidelines, and of the impact of the Italian legal requirements for research biobanking. Discussions among stakeholders facilitated the design of the informed consent and the ethico-legal framework. Several topics are addressed, including the suitability of a broad informed consent for paediatric biobanks, infant vulnerability, access to and sharing of data, and the disclosure of individual’s genetic results. Discussion of the ethical and legal procedures adopted in epidemiological biobanking might be a fruitful ground for comparison both at the national level, where standardization and homogeneity are lacking, and at the international level, where different regulatory issues are often in the background and might hamper research biobanks networking. 相似文献
116.
117.
Maria Sole Cigoli Francesca Avemaria Stefano De Benedetti Giovanni P. Gesu Lucio Giordano Accorsi Stefano Parmigiani Maria Franca Corona Valeria Capra Andrea Mosca Simona Giovannini Francesca Notturno Fausta Ciccocioppo Lilia Volpi Margherita Estienne Giuseppe De Michele Antonella Antenora Leda Bilo Antonietta Tavoni Nelia Zamponi Enrico Alfei Giovanni Baranello Daria Riva Silvana Penco 《PloS one》2014,9(10)
Cerebral cavernous malformations (CCMs) are vascular abnormalities that may cause seizures, intracerebral haemorrhages, and focal neurological deficits. Familial form shows an autosomal dominant pattern of inheritance with incomplete penetrance and variable clinical expression. Three genes have been identified causing familial CCM: KRIT1/CCM1, MGC4607/CCM2, and PDCD10/CCM3. Aim of this study is to report additional PDCD10/CCM3 families poorly described so far which account for 10-15% of hereditary cerebral cavernous malformations. Our group investigated 87 consecutive Italian affected individuals (i.e. positive Magnetic Resonance Imaging) with multiple/familial CCM through direct sequencing and Multiplex Ligation-Dependent Probe Amplification (MLPA) analysis. We identified mutations in over 97.7% of cases, and PDCD10/CCM3 accounts for 13.1%. PDCD10/CCM3 molecular screening revealed four already known mutations and four novel ones. The mutated patients show an earlier onset of clinical manifestations as compared to CCM1/CCM2 mutated patients. The study of further families carrying mutations in PDCD10/CCM3 may help define a possible correlation between genotype and phenotype; an accurate clinical follow up of the subjects would help define more precisely whether mutations in PDCD10/CCM3 lead to a characteristic phenotype. 相似文献
118.
Summary Miocene syn-rift carbonate production areas are exposed in south-eastern Sardinia (Italy) along the eastern side of the Plio-Pleistocene
Campidano Graben. Here the downfaulted margins of the Oligo-Miocene Sardinia rift-basin crop out with a complex alignment
of smaller subbasins. Carbonate factories developed during the Aquitanian times in these tectonically controlled small depositional
subbasins, where terrigenous input might be high due to the erosion of the uplifted pre-Neogene substrata. Terrigenous deposits
generally acted as passive substratum for pioneer communities of rhodalgal-type (red algae, ostreids, bryozoans) and locally
evolved into coral-dominated assemblages.
Carbonate production areas occur on tilted, uplifted blocks as well as along basement margins. These have varying organic
communities and facies characteristics strongly dependent on different environmental conditions. In footwall areas, devoid
of (or with a very reduced) terrigenous supply, open foramol carbonate factories occur with aggradational-progradational stratigraphic
geometries. The resulting pure calcareous successions are organized in sequences, bounded by tectonically driven discontinuity
surfaces.
In sectors close to the hinterland area, with a higher freshwater input and a consequent significant clastic input, coral-dominated
assemblages grew during long periods of quiescence between flash floods. Repeated coral-rich communities developed on thick
wedges of terrigenous debris.
Carbonate facies composition and distribution were mainly controlled by local syn-sedimentary tectonics and eustasy as well
as by climate. However, although the inception of the carbonate factories was presumably not synchronous, their growth represented
the response to a relative regional sea level rise subsequent to episodes of significant clastic supply: the expression of
an early syn-rift stage.
During the Burdigalian (N6 zone) a hemipelagic cover uniformly sealed the neritic successions. This basin wide drowning event
appears to correspond to the transgressive system tract of the TB2.1 cycle ofHaq
et al. (1987) but it can also be interpreted as the expression of an evolved syn-rift stage passing to late syn-rift and quiescence
stages.
Beneath the hemipelagic cover in some areas, ?late Aquitanian-early Burdigalian deep erosive surfaces, terrigenous clastics
and paleosoils have been recognized. These suggest a relative sea level fall and may relate to the global sea level drop at
the TB1-TB2 boundary (seeHaq
et al., 1987) or to diacronous uplift of different fault blocks. 相似文献
119.
Nicola Pirastu Ciara McDonnell Eryk J. Grzeszkowiak Ninon Mounier Fumiaki Imamura Jordi Merino Felix R. Day Jie Zheng Nele Taba Maria Pina Concas Linda Repetto Katherine A. Kentistou Antonietta Robino Tnu Esko Peter K. Joshi Krista Fischer Ken K. Ong Tom R. Gaunt Zoltn Kutalik John R. B. Perry James F. Wilson 《PLoS genetics》2022,18(6)
Diet is considered as one of the most important modifiable factors influencing human health, but efforts to identify foods or dietary patterns associated with health outcomes often suffer from biases, confounding, and reverse causation. Applying Mendelian randomization in this context may provide evidence to strengthen causality in nutrition research. To this end, we first identified 283 genetic markers associated with dietary intake in 445,779 UK Biobank participants. We then converted these associations into direct genetic effects on food exposures by adjusting them for effects mediated via other traits. The SNPs which did not show evidence of mediation were then used for MR, assessing the association between genetically predicted food choices and other risk factors, health outcomes. We show that using all associated SNPs without omitting those which show evidence of mediation, leads to biases in downstream analyses (genetic correlations, causal inference), similar to those present in observational studies. However, MR analyses using SNPs which have only a direct effect on the exposure on food exposures provided unequivocal evidence of causal associations between specific eating patterns and obesity, blood lipid status, and several other risk factors and health outcomes. 相似文献
120.
Dicyclina sampoi, a new larger foraminifer from the Middle to Upper Cenomanian of Zagros Range (SW Iran), is described. Although the general chamber structures ofD. sampoi and of the European Dicyclinas(D. schlumbergeri Munier-Chalmas,D. simplex Cherchi & Schroeder) are largely identical, some differences indicate a polyphyletic origin of this genus. 相似文献