The Evolution of Extracellular Fibrillins and Their Functional Domains

Fibrillins constitute the major backbone of multifunctional microfibrils in elastic and non-elastic extracellular matrices, and are known to interact with several binding partners including tropoelastin and integrins. Here, we study the evolution of fibrillin proteins. Following sequence collection from 39 organisms representative of the major evolutionary groups, molecular evolutionary genetics and phylogeny inference software were used to generate a series of evolutionary trees using distance-based and maximum likelihood methods. The resulting trees support the concept of gene duplication as a means of generating the three vertebrate fibrillins. Beginning with a single fibrillin sequence found in invertebrates and jawless fish, a gene duplication event, which coincides with the appearance of elastin, led to the creation of two genes. One of the genes significantly evolved to become the gene for present-day fibrillin-1, while the other underwent evolutionary changes, including a second duplication, to produce present-day fibrillin-2 and fibrillin-3. Detailed analysis of several sequences and domains within the fibrillins reveals distinct similarities and differences across various species. The RGD integrin-binding site in TB4 of all fibrillins is conserved in cephalochordates and vertebrates, while the integrin-binding site within cbEGF18 of fibrillin-3 is a recent evolutionary change. The proline-rich domain in fibrillin-1, glycine-rich domain in fibrillin-2 and proline-/glycine-rich domain in fibrillin-3 are found in all analyzed tetrapod species, whereas it is completely replaced with an EGF-like domain in cnidarians, arthropods, molluscs and urochordates. All collected sequences contain the first 9-cysteine hybrid domain, and the second 8-cysteine hybrid domain with exception of arthropods containing an atypical 10-cysteine hybrid domain 2. Furin cleavage sites within the N- and C-terminal unique domains were found for all analyzed fibrillin sequences, indicating an essential role for processing of the fibrillin pro-proteins. The four cysteines in the unique N-terminus and the two cysteines in the unique C-terminus are also highly conserved

Optical-Radar-DEM Remote Sensing Data Integration for Geological Mapping in the Afar Depression, Ethiopia

The advantages of integrating optical (Landsat Enhanced Thematic Mapper Plus (ETM+) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER)) and radar (Shuttle Imaging Radar (SIR) - C, X-band Synthetic Aperture Radar (SAR) and RADARSAT-1) remote sensing data, and digital elevation models (DEMs) (Shuttle Radar Topography Mission (SRTM)) for geological mapping in arid regions such as the Afar Depression in Ethiopia are demonstrated. The Afar Depression in NE Africa is a natural laboratory for studying processes of sea-floor spreading and the transition from rifting to true sea-floor spreading. It is ideal for geological remote sensing because of its vastness, remoteness and inaccessibility together with almost continuous exposure, and lack of vegetation and soil cover. Optical-radar-DEM remote sensing data integration is used for: (1) Distinguishing spatial and temporal distribution of individual lava flows in the Quaternary Erta \u27Ale Volcanic Range in the northern part of the Afar Depression, by integrating band-ratios of ASTER thermal infrared (TIR) data with Landsat ETM+ visible and near infrared (VNIR) and SIR-C/X-SAR L-band (λ = 24 cm) data with horizontally transmitted and horizontally received (HH) polarization. (2) Visualizing and interpreting extensional imbrication fans that constitute part of the Dobe Graben in the central part of the Afar Depression by integrating Landsat ETM+ VNIR data with RADARSAT C-band (λ = 6 cm) data with HH polarization and SRTM DEMs. These imbrication fans were developed as layer-parallel gravitational slip of the border fault hanging-wall towards the graben center. (3) Mapping morphologically defined structures in rhyolite flows exposed on the flanks of the Tendaho Rift by merging ASTER VNIR and short wave infrared (SWIR) with RADARSAT C-band data with HH polarization. The Tendaho Rift constitutes part of the Tendaho-Gobaad Discontinuity that separates the southern and the central eastern parts of the Afar Depression. Optical-radar-DEM data integration proved to be an effective approach for aiding geological mapping and structural analysis in arid regions such as the Afar Depression

Genetic Diversity of Related Vibriophages Isolated from Marine Environments Around Florida and Hawaii, USA

Although viruses from the marine environment have been enumerated, isolated, and characterized, there is little information on the abundance or global distribution of specific phage types. To this end, we studied the abundance and distribution of phages which infect a marine bacterium isolated from Tampa Bay (Florida, USA), tentatively identified (Microbial ID, Inc., Newark, Delaware, USA) as Vibrio parahaemolyticus. Using this host, we have isolated over 60 phages from the Gulf of Mexico, Tampa Bay, Florida Keys, and Oahu, Hawaii (USA). These isolates are all Myoviridae, with head sizes ranging from 50 +/- 0.0 to 65 +/- 4.2 nm and tail lengths of 60 +/- 3.6 to 100 +/- 5.0 nm. The type phage (Phi16 from Tampa Bay) has a double-stranded DNA genome of 51 to 58 kb. A 1.5 kb EcoRI fragment of this genome has been cloned and used as a gene probe. All of the DNA from the phage isolates hybridized to this probe under stringent conditions, but not to DNA from other marine vibriophages and bacteriophages, suggesting genetic relatedness. Agarose gel electrophoresis of EcoRI digests of the DNAs, followed by Southern transfer and probing with the 1.5 kb gene probe, yielded 6 groups based upon banding patterns. These groups were not segregated geographically within the Florida isolates; however, all of the Hawaiian phages had a common restriction pattern. These data indicate that populations of genetically related phages are widely distributed over large geographic distances in the oceans

Hyperspectral image analysis of different carbonate lithologies (limestone, karst and hydrothermal dolomites): the Pozalagua Quarry case study (Cantabria, North-west Spain)

Ground-based hyperspectral imaging combined with terrestrial lidar scanning is a novel technique for outcrop analysis, which has been applied to Early and Late Albian carbonates of the Pozalagua Quarry (Cantabrian Mountains, Spain). An image processing workflow has been developed for differentiating limestone from dolomite, providing additional sedimentary and diagenetic information, and the possibility to quantitatively delineate diagenetic phases in an accurate way. Spectral absorption signatures can be linked to specific sedimentary or diagenetic products, such as recent and palaeokarst, hydrothermal karst, (solution enlarged) fractures and different dolomite types. Some of the spectral signatures are related to iron, manganese, organic matter, clay and/or water content. Ground-truthing accessible parts of the quarry showed that the classification based on hyperspectral image interpretation was very accurate. This technique opens the possibility for quantitative data evaluation on sedimentary and diagenetic features in inaccessible outcrops. This study demonstrates the potential of ground-based imaging spectroscopy to provide information about the chemical–mineralogical distribution in outcrops, which could otherwise not be established using conventional field methods.status: publishe