Galapagos hydrothermal mounds: stratigraphy and chemistry revealed by deep-sea drilling

The Galápagos mounds sea-floor hydrothermal system is at least 300,000 years old and once produced manganese-poor sediments, which nearly blanketed the area of the present mounds field. Present-day mound deposits are limited manganese-rich exposures, suggesting that the system has changed from rock-to water-dominated and has diminished in intensity with time.     

Analysis of association between various fertility indicators and production traits in Mehsana buffaloes

Tropical Animal Health and Production - Female fertility in domestic animals in India has exhaustively suffered owing to indiscriminate breeding with single objective of increasing milk production....     

Identification and expression profiles of multiple genes in Nile tilapia in response to bacterial infections

To understand the molecular mechanisms involved in response of Nile tilapia (Oreochromis niloticus) to bacterial infection, suppression subtractive cDNA hybridization technique was used to identify upregulated genes in the posterior kidney of Nile tilapia at 6h post infection with Aeromonas hydrophila. A total of 31 unique expressed sequence tags (ESTs) were identified from 192 clones of the subtractive cDNA library. Quantitative PCR revealed that nine of the 31 ESTs were significantly (p<0.05) upregulated in Nile tilapia at 6h post infection with A. hydrophila at an injection dose of 10(5)CFU per fish (≈ 20% mortality). Of the nine upregulated genes, four were also significantly (p<0.05) induced in Nile tilapia at 6h post infection with A. hydrophila at an injection dose of 10(6)CFU per fish (≈ 60% mortality). Of the four genes induced by A. hydrophila at both injection doses, three were also significantly (p<0.05) upregulated in Nile tilapia at 6h post infection with Streptococcus iniae at doses of 10(6) and at 10(5)CFU per fish (≈ 70% and ≈ 30% mortality, respectively). The three genes induced by both bacteria included EST 2A05 (similar to adenylate kinase domain containing protein 1), EST 2G11 (unknown protein, shared similarity with Salmo salar IgH locus B genomic sequence with e value of 0.02), and EST 2H04 (unknown protein). Significant upregulation of these genes in Nile tilapia following bacterial infections suggested that they might play important roles in host response to infections of A. hydrophila and S. iniae.     

High-throughput approach to detection of knockdown resistance (kdr) mutation in mosquitoes, Culex quinquefasciatus, based on real-time PCR using single-labelled hybridisation probe/melting curve analysis

BACKGROUND: Knockdown resistance (kdr) mutation (L1014F) is a well‐defined mechanism of resistance to pyrethroids and DDT in many insect species. Sensitive detection of the mutations associated with resistance is a prerequisite for resistance management strategies. The authors have developed a new real‐time molecular diagnostic assay based on SimpleProbe^®/melting curve analysis for large‐scale kdr genotyping in the wild population of Culex quinquefasciatus Say, the principal vector of bancroftian filariasis. Melting curve analysis is based on the thermal stability difference between matched and mismatched DNA duplexes. The application of SimpleProbe^® chemistry in insects described here is novel in entomology research. RESULTS: The mosquitoes homozygous for knockdown‐resistant and knockdown‐susceptible allele showed melting peaks at 60.45 °C ( ± 0.25) and 64.09 °C ( ± 0.24) respectively. The heterozygous mosquitoes yielded both peaks at approximately 60.5 °C ( ± 0.2) and 64.20 °C ( ± 0.23). Among the 92 samples genotyped, 16 were found to be homozygous resistant, 44 homozygous susceptible and 32 heterozygous. Comparative assessments were made of all the reported methods for kdr genotyping. CONCLUSION: The present method is cheaper, faster, more reliable and versatile than other alternatives proposed in detecting correct kdr genotypes in mosquitoes. This is the first report using a single‐labelled hybridisation probe to detect point mutations in insect populations. Copyright © 2010 Society of Chemical Industry     

Normal cells of patients with high cancer risk syndromes lack transforming activity in the NIH/3T3 transfection assay

Oncogenes capable of transforming NIH/3T3 cells are often present in human tumors and tumor cell lines. Such oncogenes were not detected in normal fibroblast lines derived from patients with several clinical syndromes associated with greatly increased cancer risk. Thus, germ-line transmission of these oncogenes does not appear to be the predisposing factor responsible for these high cancer risk syndromes.     

AGTR2 mutations in X-linked mental retardation

Two angiotensin II (Ang II)-specific receptors, AGTR1 and AGTR2, are expressed in the mammalian brain. Ang II actions on blood pressure regulation, water electrolyte balance, and hormone secretion are primarily mediated by AGTR1. The function of AGTR2 remains unclear. Here, we show that expression of the AGTR2 gene was absent in a female patient with mental retardation (MR) who had a balanced X;7 chromosomal translocation. Additionally, 8 of 590 unrelated male patients with MR were found to have sequence changes in the AGTR2 gene, including one frameshift and three missense mutations. These findings indicate a role for AGTR2 in brain development and cognitive function.     

Molecular dynamics simulations of dimer opening on a diamond {001}(2x1) surface

Computer simulations of hydrocarbon and related molecules using empirical force fields have become important tools for studying a number of biological and related processes at the atomic scale. Traditional force fields, however, cannot be used to simulate dynamic chemical reactivity that involves changes in atomic hybridization. Application of a many-body potential function allows such reactivity to occur in a computer simulation. Simulations of the reaction of small hydrocarbon molecules adsorbed on a reconstructed diamond {001}(2x1) surface suggest that these hydrocarbons are highly reactive species and that initial stages of diamond growth proceed through a dimer-opening mechanism. Rates estimated from transition state theory of two interconversions between states where the dimer is open and closed are given.