Patterns and Processes of Groundwater Invasion by Copepods in the Interior Low Plateaus of the United States

The copepod crustacean fauna collected from subterranean habitats, including caves, wells, and the hyporheos of streams in and near the Interior Low Plateaus of the United States is dominated by Cyclopoida, with 39 species, followed by Harpacticoida with 9, and Calanoida with 2. Nearly all of the harpacticoid and calanoid species are widespread, primarily surface-dwelling generalists. Fourteen of the cyclopoids, members of the genera Diacyclops, Itocyclops, Megacyclops, and Rheocyclops, are apparently obligate stygobionts or hyporheic. Several of the species that are more strongly modified for subterranean existence occur only in the more southern, unglaciated areas. Our sampling data support the hypothesis that the more specialized, groundwater-interstitial species have been unable to disperse into previously glaciated regions; whereas some, less-specialized species may have invaded groundwaters from surface habitats as the glaciers receded

First Records of Two Neotropical Species of Mesocyclops (Copepoda) from Yukon Territory: Cases of Passive Dispersal?

Two species of neotropical cyclopoid copepod crustaceans, Mesocyclops longisetus curvatus and Mesocyclops venezolanus, were collected from a pond at Shingle Point, Yukon Territory, Canada, in September 1974. This is the first record of M. longisetus curvatus north of the southern United States and the first record of M. venezolanus north of Honduras. We provide amplified descriptions of both species. Four additional congeners, M. americanus, M. edax, M. reidae, and M. ruttneri, are now known from the continental U.S. and Canada. We provide a key to the identification of the six species. We hypothesize that the specimens of M. longisetus curvatus and M. venezolanus may have been passively transported to Shingle Point by migrant shorebirds.Key words: Copepoda, Cyclopoida, Mesocyclops, new record, Yukon, neotropical, zoogeography, passive dispersal, identification keyEn septembre 1974, on a recueilli deux espèces de copépodes cyclopoïdes néogènes, Mesocyclops longisetus curvatus et Mesocyclops venezolanus, dans un étang situé à Shingle Point, dans le territoire du Yukon au Canada. Cela représente la première occurrence rapportée de M. longisetus curvatus au nord de la partie méridionale des États-Unis, et la première de M. venezolanus au nord du Honduras. On donne une description détaillée des deux espèces. On sait maintenant qu'il existe quatre autres congénères, M. americanus, M. edax, M. reida et M. ruttneri, aux États-Unis américains et au Canada. On fournit un code permettant d'identifier les six espèces. On émet l'hypothèse que les spécimens de M. longisetus curvatus et de M. venezolanus ont pu être transportés de façon passive à Shingle Point par des oiseaux de rivage migrateurs.Mots clés: copépodes, cyclopoïdes, Mesocyclops, nouvelle Occurrence rapportée, Yukon, néogène, zoogéographie, dispersion passive, code d'identificatio

Chave de identificação e lista de referências bibliográficas para as espécies continentais sulamericanas de vida livre da ordem Cyclopoida (Crustacea, Copepoda)

Uma chave ilustrada é fornecida para auxiliar na identificação das 108 espécies, subespêcies e formas de Copepoda, Cyclopoida (Crustacea) de vida livre, conhecidas da América do Sul continental, incluindo as Ilhas Malvinas/Falklands, Aruba e Curaçao. Estão incluidos os membros dos gêneros predominantemente marinhos, gue podem ocorrer em estuários e lagoas salobras. Cada especie é suprida de uma lista de referências bibliográficas

Hallazgo de mesocyclops aspericornis (Daday) (Copepoda: Cyclopidae) depredador de larvas de aedes aegypti en Anapoima Colombia (1)

In Anapoima, Colombia, the copepod Mesocyclos aspericornis was found to be a predator of larvas of the mosquito Aedes aegypti. This is the first finding of this copepod in artificial containers in the Neotropical Region, and the first finding as a predator of Aedes aegypti.En Anapoima, Colombia, se encontró que el copépodo Mesocyclops aspericornis era depredador de larvas del mosquito Aedes aegypti. Este encuentro representa el primer hallazgo de este copépodo en recipientes artificiales en la región neotropical, y el primer hallazgo como depredador de larvas de Aedes aegypti

Atomic-resolution crystal structures of the immune protein conglutinin from cow reveal specific interactions of its binding site with N-acetylglucosamine.

Bovine conglutinin is an immune protein that is involved in host resistance to microbes and parasites and interacts with complement component iC3b, agglutinates erythrocytes, and neutralizes influenza A virus. Here, we determined the high-resolution (0.97-1.46 Å) crystal structures with and without bound ligand of a recombinant fragment of conglutinin's C-terminal carbohydrate-recognition domain (CRD). The structures disclosed that the high-affinity ligand N-acetyl-D-glucosamine (GlcNAc) binds in the collectin CRD calcium site by interacting with the O3' and O4' hydroxyls alongside additional specific interactions of the N-acetyl group oxygen and nitrogen with Lys343 and Asp320, respectively. These residues, unique to conglutinin and differing both in sequence and location from those in other collectins, result in specific, high-affinity binding for GlcNAc. The binding pocket flanking residue Val339, unlike the equivalent Arg343 in the homologous human surfactant protein D, is sufficiently small to allow conglutinin Lys343 access to the bound ligand, whereas Asp320 lies in an extended loop proximal to the ligand-binding site and bounded at both ends by conserved residues that coordinate to both calcium and ligand. This loop becomes ordered on ligand binding. The electron density revealed both a and ß anomers of GlcNAc, consistent with the added a/ßGlcNAc mixture. Crystals soaked with a1-2 mannobiose, a putative component of iC3b, reported to bind to conglutinin, failed to reveal bound ligand, suggesting a requirement for presentation of mannobiose as part of an extended physiological ligand. These results reveal a highly specific GlcNAc-binding pocket in conglutinin and a novel collectin mode of carbohydrate recognition

Molecular Basis of Increased Serum Resistance among Pulmonary Isolates of Non-typeable Haemophilus influenzae

Non-typeable Haemophilus influenzae (NTHi), a common commensal of the human pharynx, is also an opportunistic pathogen if it becomes established in the lower respiratory tract (LRT). In comparison to colonizing isolates from the upper airway, LRT isolates, especially those associated with exacerbations of chronic obstructive pulmonary disease, have increased resistance to the complement- and antibody-dependent, bactericidal effect of serum. To define the molecular basis of this resistance, mutants constructed in a serum resistant strain using the mariner transposon were screened for loss of survival in normal human serum. The loci required for serum resistance contribute to the structure of the exposed surface of the bacterial outer membrane. These included loci involved in biosynthesis of the oligosaccharide component of lipooligosaccharide (LOS), and vacJ, which functions with an ABC transporter encoded by yrb genes in retrograde trafficking of phospholipids from the outer to inner leaflet of the cell envelope. Mutations in vacJ and yrb genes reduced the stability of the outer membrane and were associated with increased cell surface hyrophobicity and phospholipid content. Loss of serum resistance in vacJ and yrb mutants correlated with increased binding of natural immunoglobulin M in serum as well as anti-oligosaccharide mAbs. Expression of vacJ and the yrb genes was positively correlated with serum resistance among clinical isolates. Our findings suggest that NTHi adapts to inflammation encountered during infection of the LRT by modulation of its outer leaflet through increased expression of vacJ and yrb genes to minimize recognition by bactericidal anti-oligosaccharide antibodies

Efficient Generation of Germ Line Transmitting Chimeras from C57BL/6N ES Cells by Aggregation with Outbred Host Embryos

Genetically modified mouse strains derived from embryonic stem (ES) cells have become essential tools for functional genomics and biomedical research. Large scale mutagenesis projects are producing libraries of mutant C57BL/6 (B6) ES cells to enable the functional annotation of every gene of the mouse genome. To realize the utility of these resources, efficient and accessible methods of generating mutant mice from these ES cells are necessary. Here, we describe a combination of ICR morula aggregation and a chemically-defined culture medium with widely available and accessible components for the high efficiency generation of germline transmitting chimeras from C57BL/6N ES cells. Together these methods will ease the access of the broader biomedical research community to the publicly available B6 ES cell resources

Communications Biophysics

Contains reports on seven research projects split into three sections.National Institutes of Health (Grant 5 PO1 NS13126)National Institutes of Health (Grant 1 RO1 NS18682)National Institutes of Health (Training Grant 5 T32 NS07047)National Science Foundation (Grant BNS77-16861)National Institutes of Health (Grant 1 F33 NS07202-01)National Institutes of Health (Grant 5 RO1 NS10916)National Institutes of Health (Grant 5 RO1 NS12846)National Institutes of Health (Grant 1 RO1 NS16917)National Institutes of Health (Grant 1 RO1 NS14092-05)National Science Foundation (Grant BNS 77 21751)National Institutes of Health (Grant 5 R01 NS11080)National Institutes of Health (Grant GM-21189