Search results for "arthropods"

Identification of four distinct subunit types in the unique 6 x 6 hemocyanin of the centipede Scutigera coleoptrata.

1999

We isolated 6 x 6 hemocyanin, dissociated it into subunits, and examined it by electron microscopy. The subunits were separated by native polyacrylamide gel electrophoresis (PAGE), sodium dodecyl sulfate PAGE, and crossed immunoelectrophoresis. Single subunits were isolated by gel cutting from native PAGE and identified as hemocyanin by measuring their ultraviolet spectrum. A total of four distinct hemocyanin subunits were identified, and the subunit pattern of the three electrophoresis systems assigned to each other. The relative proportion of subunits a:b:c:d were 2 : 2 :: 1 as determined by densitometry. Presumably, c and d act as linkers between hexamers.

The comparison of beta-thymosin homologues among metazoa supports an arthropod-nematode clade.

2000

The definition of an Ecdysozoa clade among the protostomians, including all phyla with a regularly molted alpha-chitin-rich cuticle, has been one of the most provocative hypotheses to arise from recent investigations on animal phylogeny. Here we present evidence in favor of an arthropod-nematode clade, from the comparison of beta-thymosin homologues among the Metazoa. Arthropods and nematodes share the absence of the highly conserved beta-thymosin form found in all other documented bilaterian phyla as well as sponges, and the possession of a very unusual, internally triplicated homologue of the beta-thymosin protein, unknown in other phyla. We argue that such discrete molecular character is…

Evolutionary history and diversity of arthropod hemocyanins

2004

Hemocyanins are copper-containing, multi-subunit proteins that transport oxygen in the hemolymph of many molluscs and arthropods [Markl and Decher, Adv. Comp. Environ. Physiol. 13 (1992) 325; van Holde et al., J. Biol. Chem. 276 (2001) 15563]. Arthropod hemocyanins originated more than 550 million years ago from oxygen-consuming phenoloxidases. Hemocyanins are present in various Onychophora, Chelicerata, Myriapoda, Crustacea, and Hexapoda, but subunit evolution differs striking in these arthropod subphyla. Hemocyanins also gave rise to non-respiratory proteins (crustacean pseudo-hemocyanins, insect hexamerins, and hexamerin receptors), which most likely have storage functions.

On the stability of the 24-meric hemocyanin from Eurypelma californicum.

1998

The stability of the 24-meric hemocyanin from Eurypelma californicum towards various denaturants (GdnHCl, urea, urea derivatives and salts of the Hofmeister series) indicates that the quaternary structure is stabilized by hydrophilic and polar forces. Thus, the interaction between the seven different subunit types of this cheliceratan hemocyanin is comparable with that of the closely related crustacean hemocyanins. In contrast, no significant influence of divalent ions such as Ca2+ and Mg2+ on the stability is observed at pH 8.0 and pH 8.5 but not at pH 7.0. Studies, both in the presence of urea and GdnHCl indicate that the denaturation process consists of a dissociation of the oligomeric s…

Biodiversity in the grapevine: rhizosphere arthropods and mycorrhizal fungi

2007

New Insight into Immunity and Immunopathology of Rickettsial Diseases

2011

Human rickettsial diseases comprise a variety of clinical entities caused by microorganisms belonging to the generaRickettsia,Orientia,Ehrlichia, andAnaplasma. These microorganisms are characterized by a strictly intracellular location which has, for long, impaired their detailed study. In this paper, the critical steps taken by these microorganisms to play their pathogenic roles are discussed in detail on the basis of recent advances in our understanding of molecularRickettsia-host interactions, preferential target cells, virulence mechanisms, three-dimensional structures of bacteria effector proteins, upstream signalling pathways and signal transduction systems, and modulation of gene exp…

Ecological and social impacts of photovoltaic solar power plants and optimization of their locations in northern Chile

2017

Large scale photovoltaic (PV) solar power plants are gaining popularity in Chile. Solar energy potential in northern Chile is one of the best worldwide and true deserts are considered ideal environments for solar power plant projects. Atacama Desert is one of the driest places on earth. Nevertheless, northern Chile is home for many endemic species with 40 different vegetation types. The thesis presents studies of ecological effects (I-II) and location optimization of PV solar power plants in northern Chile (III). For ecological impacts two types of PV solar power plant technologies were studied: fixed mount solar plant and solar- tracking mounts. Study units were placed below the mounts or …

Data from: The interplay of landscape composition and configuration: new pathways to manage functional biodiversity and agro-ecosystem services acros…

2019

[Usage Notes] Martin et al_2019_datatables Data used in Martin et al. (2019) compiled from 49 studies and 1,515 landscapes across Europe. Includes data on the abundance of arthropod species per site and data on pollination, natural pest control and yields in crops across Europe. Martin et al_2019_data tables_300319.xlsx Martin et al_2019_traits database Functional traits data for 2088 species (morphospecies, individuals) from 144 arthropod families sampled in agricultural landscapes across Europe. All traits are categorical and based on published literature or expert knowledge. They are described in Table 1 and Appendix S1 of Martin et al. (2019). The traits included are: feeding habit ('Fu…

Augsnes mezofaunas struktūra Engures ezera dabas parkā

2018

Bakalaura darba pētījums veikts Engures ezera dabas parka ekoreģionā un tā tuvākajā apkārtnē. Darbā tiek aprakstīta augsnes mezofauna un analizēta tās veidotās struktūras dažādos biotopos un to parauglaukumos, kas iekļauti ILTER (International Longt Term Ecological Research network) programmā. Bakalaura darbā iekļauta vispārīga informācija par augsnes faunu un parauglaukumos konstatētajiem mezofaunas pārstāvjiem. Pētījums ir veikts sešos biotopos. Katrā parauglaukumā noteikts mezofaunas taksonomiskais sastāvs, struktūra un tās blīvums. Bakalaura darba izstrādes laikā autore apguva augsnes mezofaunas ievākšanas un noteikšanas metodiku, kā arī ieguva zināšanas un izpratni par mezofaunas nozīm…