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Native Environment (native + environment)
Selected AbstractsThe biogeography of prediction error: why does the introduced range of the fire ant over-predict its native range?GLOBAL ECOLOGY, Issue 1 2007Matthew C. Fitzpatrick ABSTRACT Aim, The use of species distribution models (SDMs) to predict biological invasions is a rapidly developing area of ecology. However, most studies investigating SDMs typically ignore prediction errors and instead focus on regions where native distributions correctly predict invaded ranges. We investigated the ecological significance of prediction errors using reciprocal comparisons between the predicted invaded and native range of the red imported fire ant (Solenopsis invicta) (hereafter called the fire ant). We questioned whether fire ants occupy similar environments in their native and introduced range, how the environments that fire ants occupy in their introduced range changed through time relative to their native range, and where fire ant propagules are likely to have originated. Location, We developed models for South America and the conterminous United States (US) of America. Methods, We developed models using the Genetic Algorithm for Rule-set Prediction (GARP) and 12 environmental layers. Occurrence data from the native range in South America were used to predict the introduced range in the US and vice versa. Further, time-series data recording the invasion of fire ants in the US were used to predict the native range. Results, Native range occurrences under-predicted the invasive potential of fire ants, whereas occurrence data from the US over-predicted the southern boundary of the native range. Secondly, introduced fire ants initially established in environments similar to those in their native range, but subsequently invaded harsher environments. Time-series data suggest that fire ant propagules originated near the southern limit of their native range. Conclusions, Our findings suggest that fire ants from a peripheral native population established in an environment similar to their native environment, and then ultimately expanded into environments in which they are not found in their native range. We argue that reciprocal comparisons between predicted native and invaded ranges will facilitate a better understanding of the biogeography of invasive and native species and of the role of SDMs in predicting future distributions. [source] Overlay for Membrane-Bound Protein Biochips:IMAGING & MICROSCOPY (ELECTRONIC), Issue 4 2009A Combined Optical Microscopy, AFM Study Phospholipids bilayer membrane represents a fundamental element within the cell, protecting the inner cell from the outside while enabling the communication of the cell with its environment. Composed of several kinds of phospholipids, mixed at defined ratio, it presents also numerous proteins assembly as for example chemotaxis receptors, or larger structure such as the bacterial flagellar Nano-Motor [1]. Despite its importance, studying phospholipids membrane in native environment remains challenging due to numerous technical limitations. [source] Vernalization requirement of wild beet Beta vulgaris ssp. maritima: among population variation and its adaptive significanceJOURNAL OF ECOLOGY, Issue 4 2002Pierre Boudry Summary 1Seven populations of Beta vulgaris ssp. maritima (wild beet) situated along a latitudinal cline were studied for their vernalization requirement and its consequences for fitness. 2Various cold regimes were applied in glasshouses and experimental gardens with plants of different ages. Three additional experimental sites (on the French Mediterranean, Atlantic and North Sea coasts) situated near three of the sampled populations, and thus including a reciprocal transplant design, were used to evaluate the influence of latitude under natural conditions. Survival and plant size were measured over 3 years. 3The vernalization requirement was greater in plants from more northern origins. The level of cold required to allow flowering overcompensated for the colder springs, so that northern plants in northern sites flowered less than southern plants in southern sites. 4Young seedlings were more difficult to vernalize than plants that had already developed vegetative rosettes. 5Differences in vernalization requirement seem to be an adaptive response to spring temperatures and season length in a particular latitude. A whole winter vernalization almost always led to flowering in the subsequent year whatever the latitude or geographical origin. 6Plants from the Atlantic and Channel coasts showed the highest lifetime reproductive success at all sites. Southern populations were better adapted to disturbed habitats as shown by their higher first-year reproductive success. The North Sea population had a lower reproductive success than the Atlantic populations, even in its native environment. [source] Gene expression in skeletal tissues: application of laser capture microdissectionJOURNAL OF MICROSCOPY, Issue 1 2005D. Benoyahu Summary Tissue differentiation is based on the expression of transcription factors, receptors for cytokines, and nuclear receptors that regulate a specific phenotype. The purpose of this study was to select cells from various skeletal tissues in order to analyse differential gene expression of cells in the native environment in vivo. It is a difficult task to obtain cells from skeletal tissues, such as cartilage, periost, bone and muscle, that are structured together and do not exist as individual organs. We used laser capture microdissection which permits the selection and isolation of individual cells from tissue sections. The RNA isolated from these tissues was used for reverse transcriptase-polymerase chain reactions for molecular analysis. We analysed the expression of transcription factors (cFOS, cbfa1, MyoD), receptors for cytokines, nuclear receptors, alkaline phosphatase and the structural proteins osteocalcin and collagen II. The results obtained demonstrate differential patterns of gene expression according to the tissue arrangement in their native in vivo environment, with reliable interpretation of the functions of the analysed genes in the context of intact skeletal tissue physiology. [source] Live imaging of fluorescent proteins in chordate embryos: From ascidians to miceMICROSCOPY RESEARCH AND TECHNIQUE, Issue 3 2006Yale J. Passamaneck Abstract Although we have advanced in our understanding of the molecular mechanisms intrinsic to the morphogenesis of chordate embryos, the question of how individual developmental events are integrated to generate the final morphological form is still unresolved. Microscopic observation is a pivotal tool in developmental biology, both for determining the normal course of events and for contrasting this with the results of experimental and pathological perturbations. Since embryonic development takes place in three dimensions over time, to fully understand the events required to build an embryo we must investigate embryo morphogenesis in multiple dimensions in situ. Recent advances in the isolation of naturally fluorescent proteins, and the refinement of techniques for in vivo microscopy offer unprecedented opportunities to study the cellular and molecular events within living, intact embryos using optical imaging. These technologies allow direct visual access to complex events as they happen in their native environment, and thus provide greater insights into cell behaviors operating during embryonic development. Since most fluorescent protein probes and modes of data acquisition are common across species, we have chosen the mouse and the ascidian, two model organisms at opposite ends of the chordate clade, to review the use of some of the current genetically-encoded fluorescent proteins and their visualization in vivo in living embryos for the generation of high-resolution imaging data. Microsc. Res. Tech. 69:160,167, 2006. © 2006 Wiley-Liss, Inc. [source] Semisynthesis of unnatural amino acid mutants of paxillin: Protein probes for cell migration studiesPROTEIN SCIENCE, Issue 3 2007Elizabeth M. Vogel Abstract Caged phosphopeptides and phosphoproteins are valuable tools for dissecting the dynamic role of phosphorylation in complex signaling networks with temporal and spatial control. Demonstrating the broad scope of phosphoamino acid caging for studying signaling events, we report here the semisynthesis of a photolabile precursor to the cellular migration protein paxillin, which is a complex, multidomain phosphoprotein. This semisynthetic construct provides a powerful probe for investigating the influence that phosphorylation of paxillin at a single site has on cellular migration. The 61-kDa paxillin construct was assembled using native chemical ligation to install a caged phosphotyrosine residue at position 31 of the 557-residue protein, and the probe includes all other binding and localization determinants in the paxillin macromolecule, which are essential for creating a native environment to investigate phosphorylation. Following semisynthesis, paxillin variants were characterized through detailed biochemical analyses and by quantitative uncaging studies. [source] | |||||||||||||