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Rapid Isolation (rapid + isolation)
Selected AbstractsPliocene forest dynamics as a primary driver of African bird speciationGLOBAL ECOLOGY, Issue 1 2010Gary Voelker ABSTRACT Aim, Montane tropics are areas of high endemism, and mechanisms driving this endemism have been receiving increasing attention at a global scale. A general trend is that climatic factors do not explain the species richness of species with small to medium-sized geographic ranges, suggesting that geological and evolutionary processes must be considered. On the African continent, several hypotheses including both refugial and geographic uplift models have been advanced to explain avian speciation and diversity in the lowland forest and montane regions of central and eastern Africa; montane regions in particular are recognized as hotspots of vertebrate endemism. Here, we examine the possible role of these models in driving speciation in a clade of African forest robins. Location, Africa. Methods, We constructed the first robustly supported molecular phylogenetic hypothesis of forest robins. On this phylogeny, we reconstructed habitat-based distributions and geographic distributions relative to the Albertine Rift. We also estimated the timing of lineage divergences via a molecular clock. Results, Robust estimates of phylogenetic relationships and clock-based divergences reject Miocene tectonic uplift and Pleistocene forest refugia as primary drivers of speciation in forest robins. Instead, our data suggest that most forest robin speciation took place in the Late Pliocene, from 3.2 to 2.2 Ma. Distributional patterns are complex, with the Albertine Rift region serving as a general east,west break across the group. Montane distributions are inferred to have evolved four times. Main conclusions, Phylogenetic divergence dates coincide with a single period of lowland forest retraction in the late Pliocene, suggesting that most montane speciation resulted from the rapid isolation of populations in montane areas, rather than montane areas themselves being drivers of speciation. This conclusion provides additional evidence that Pliocene climate change was a major driver of speciation in broadly distributed African animal lineages. We further show that lowland forest robins are no older than their montane relatives, suggesting that lowland areas are not museums which house ,ancient' taxa; rather, for forest robins, montane areas should be viewed as living museums of a late Pliocene diversification event. A forest refugial pattern is operating in Africa, but it is not constrained to the Pleistocene. [source] Rapid induction of apoptosis in B-cell lymphoma by functionally isolated human antibodiesINTERNATIONAL JOURNAL OF CANCER, Issue 2 2006Johan Fransson Abstract Novel panning and screening methodology was devised to isolate high affinity human recombinant scFv antibody fragments with functionally associated properties in B lymphoma cells. The approach was used to generate a panel of apoptosis-inducing antibodies specific for antigens differentially expressed in B lymphoma vs. T leukaemia cells. The selections resulted in an antibody pool with near perfect selectivity (>99%) for the B lymphoma target cells. Randomly picked clones (72) revealed 7 unique antibody genotypes. Six of these rapidly induced apoptosis in target cells. Following the conversion to full IgGs, the antibodies were shown to be specific for HLA-DR/DP, the B-cell receptor , chain and for CD54/ICAM-1. The latter receptor was not previously associated with apoptotic properties in B-cell lymphomas. Anti-ICAM-1 IgG induced apoptosis in a broad range of B lymphoma cell lines and were shown by immunohistochemistry to bind strongly to B lymphoma tissue obtained from 5 different B lymphoma patients. The recombinant IgG antibodies had affinities in the subnanomolar (0.3 nM) to nanomolar (3 nM) range. The described technology is generally applicable for the rapid isolation of high affinity human antibodies with specificity for differentially expressed cell surface receptors with intrinsic negative or positive signalling properties from naïve phage libraries. © 2006 Wiley-Liss, Inc. [source] DNA extraction method for PCR in mycorrhizal fungiLETTERS IN APPLIED MICROBIOLOGY, Issue 4 2001S. Manian Aims: To develop a simple and rapid DNA extraction protocol for PCR in mycorrhizal fungi. Methods and Results: The protocol combines the application of rapid freezing and boiling cycles and passage of the extracts through DNA purification columns. PCR amplifiable DNA was obtained from a number of endo- and ecto-mycorrhizal fungi using minute quantities of spores and mycelium, respectively. Conclusions: DNA extracted following the method, was used to successfully amplify regions of interest from high as well as low copy number genes. The amplicons were suitable for further downstream applications such as sequencing and PCR-RFLPs. Significance and Impact of the Study: The protocol described is simple, short and facilitates rapid isolation of PCR amplifiable genomic DNA from a large number of fungal isolates in a single day. The method requires only minute quantities of starting material and is suitable for mycorrhizal fungi as well as a range of other fungi. [source] A rapid isolation and identification method for blocked N-terminal peptides by isothiocyanate-coupled magnetic nanoparticles and MSPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 18 2009Liyan Zhao Abstract A quick isolation and identification of N-blocked peptides from protein digest mixtures were achieved by diisothiocyanate or isothiocyanate-coupled magnetic nanoparticles and MS. After protein digests were guanidinated and then mixed with diisothiocyanate or isothiocyanate-coupled magnetic nanoparticles, unmodified N-terminal peptides were covalently bound to magnetic nanoparticles, and can be removed from the mixture under magnetic field. Therefore, N-blocked peptides could be isolated and analyzed by MALDI or ESI MS. This new strategy was demonstrated with model peptides, proteins, and the lysates of HepG2 cells. [source] Identification and Repair of Positive Binding Antibodies Containing Randomly Generated Amber Codons from Synthetic Phage Display LibrariesBIOTECHNOLOGY PROGRESS, Issue 3 2006Warren D. Marcus Phage display technology allows for the rapid isolation and characterization of monoclonal antibodies that have vast potential for therapeutic and diagnostic applications. However, the panning process, which utilizes a host strain that suppresses termination by the amber codon, has an inherent bias toward clones containing randomly generated amber stop codons, complicating identification of positive binding antibodies when the antibody genes are finally expressed in a nonsupressor host. Here, we perform biopanning against a Histone 2A peptide using streptavidin- or anti-biotin-coated beads. After four rounds, a dominant clone is characterized but contains a spurious amber stop codon. A protocol is given that readily corrects the amber codon, allowing for soluble antibody production once the phagemid is transformed into a nonsuppressor bacterial strain. This work also highlights the ability to isolate antibodies against a protein antigen by using only a small peptide (15 amino acids) representing a portion of the antigen. [source] | ||||||||||