Search results for "Primer"
showing 10 items of 530 documents
In murine 3T3 fibroblasts, different second messenger pathways resulting in the induction of NO synthase II (iNOS) converge in the activation of tran…
1996
Transcription factor NF-kappaB is essential for the induction of nitric oxide synthase (NOS) II (iNOS) by bacterial lipopolysaccharide in murine macrophages (Xie, Q. W., Kashiwabara, Y., and Nathan, C. (1994) J. Biol. Chem. 269, 4705-4708). In 3T3 fibroblasts, agents other than cytokines are efficacious inducers of NOS II expression. In addition to cytokines such as interferon-gamma or tumor necrosis factor-alpha, protein kinase C-stimulating agents such as tetradecanoylphorbol-13-acetate, or cyclic AMP-elevating agents such as forskolin and 8-bromo-cAMP markedly increased NOS II mRNA (measured by Sl nuclease and RNase protection analyses), NOS II protein (determined by Western blotting), a…
Cytoglobin: A Novel Globin Type Ubiquitously Expressed inVertebrate Tissues
2002
Vertebrates possess multiple respiratory globins that differ in terms of structure, function, and tissue distribution. Three types of globins have been described so far: hemoglobin facilitates the transport of oxygen in the blood, myoglobin serves oxygen transport and storage in the muscle, and neuroglobin has a yet unidentified function in nerve cells. Here we report the identification of a fourth and novel type of globin in mouse, man, and zebrafish. It is expressed in apparently all types of human tissue and therefore has been called cytoglobin (CYGB). Mouse and human CYGBs comprise 190 amino acids; the zebrafish CYGB, 174 amino acids. The human CYGB gene is located on chromosome 17q25. …
Side-stepping secondary symbionts: widespread horizontal transfer across and beyond the Aphidoidea.
2003
To elucidate the co-evolutionary relationships between phloem-feeding insects and their secondary, or facultative, bacterial symbionts, we explore the distributions of three such microbes--provisionally named the R-type (or PASS, or S-sym), T-type (or PABS), and U-type--across a number of aphid and psyllid hosts through the use of diagnostic molecular screening techniques and DNA sequencing. Although typically maternally transmitted, phylogenetic and pairwise divergence analyses reveal that these bacteria have been independently acquired by a variety of unrelated insect hosts, indicating that horizontal transfer has helped to shape their distributions. Based on the high genetic similarity b…
Expression of one sponge Iroquois homeobox gene in primmorphs from Suberites domuncula during canal formation
2003
SUMMARY Sponges (Porifera) represent the evolutionary oldest multicellular animals. They are provided with the basic molecules involved in cell–cell and cell–matrix interactions. We report here the isolation and characterization of a complementary DNA from the sponge Suberites domuncula coding for the sponge homeobox gene, SUBDOIRX-a. The deduced polypeptide with a predicted Mr of 44,375 possesses the highly conserved Iroquois-homeodomain. We applied in situ hybridization to localize Iroquois in the sponge. The expression of this gene is highest in cells adjacent to the canals of the sponge in the medulla region. To study the expression of Iroquois during development, the in vitro primmorph…
Plasmid-encoded anthranilate synthase (TrpEG) in Buchnera aphidicola from aphids of the family pemphigidae
1999
Aphids are dependent on an intracellular symbiont (Buchnera aphidicola, Proteobacteria) for normal growth and reproduction (7, 19, 45). The bacteria reside in specialized cells in the aphid hemocele and are transmitted maternally through infection of eggs or embryos (11, 26). Phylogenetic studies have revealed two major characteristics of the evolutionary history of the association (37, 39); (i) the symbiosis had a single origin, dated about 150 million to 250 million years ago; and (ii) host and symbiont lineages have since diverged strictly in parallel. The association, like other symbioses in insects feeding on restricted and unbalanced diets, is thought to have a nutritional basis (5–7,…
Study of polymorphisms in the promoter region of ovine β-lactoglobulin gene and phylogenetic analysis among the Valle del Belice breed and other shee…
2012
The aim of this work was to sequence the promoter region of b-lactoglobulin (BLG) gene in four sheep breeds, in order to identify polymorphisms, infer and analyze haplotypes, and phylogenetic relationship among the Valle del Belice breed and the other three breeds considered as ancestors. Sequencing analysis and alignment of the obtained sequences showed the presence of 36 single nucleotide polymorphisms (SNPs) and one deletion. A total of 22 haplotypes found in ‘‘best’’ reconstruction were inferred considering the 37 polymorphic sites identified. Haplotypes were used for the reconstruction of a phylogenetic tree using the Neighbor-Joining algorithm. The number of polymorphisms identified s…
Phylogenetic relationships of the family Campulidae (Trematoda) based on 18S rRNA sequences
1998
Traditionally, the family Campulidae has been associated either with the family Fasciolidae, parasites of ruminants, or the Acanthocolpidae, parasites of fishes, based on morphological similarities. Since morphology does not seem to resolve clearly the problem of the relationships of campulids, we have used the sequences of the 18S rRNA gene of the campulids Zalophotrema hepaticum, Campula oblonga and Nasitrema globicephalae, the fasciolid Fasciola hepatica, the acanthocolpid Stephanostomum baccatum and the outgroup Schistosoma mansoni to infer a phylogeny. Maximum parsimony and neighbour-joining methods were applied. Both methods indicated that campulids are closer to acanthocolpids than f…
Multiple overseas dispersal in amphibians
2003
Amphibians are thought to be unable to disperse over ocean barriers because they do not tolerate the osmotic stress of salt water. Their distribution patterns have therefore generally been explained by vicariance biogeography. Here, we present compelling evidence for overseas dispersal of frogs in the Indian Ocean region based on the discovery of two endemic species on Mayotte. This island belongs to the Comoro archipelago, which is entirely volcanic and surrounded by sea depths of more than 3500 m. This constitutes the first observation of endemic amphibians on oceanic islands that did not have any past physical contact to other land masses. The two species of frogs had previously been tho…
Soldier formation regulated by a primer pheromone from the soldier frontal gland in a higher termite, Nasutitermes lujae
1984
In the nasute higher termite Nasutitermes lujae , the differentiation of new soldiers is suppressed or delayed by the soldiers themselves. Experimental data strongly suggest that this inhibitory effect results from the action of a primer pheromone secreted by the frontal gland of soldiers. The pheromone must be contacted directly. Thus, the frontal gland of termite soldiers assumes a new role in addition to alarm and defense, although this extension cannot be generalized to all termite species. The soldier inhibitory pheromone is evidently only one of multiple factors contributing soldier regulation in termite societies.