Phylogenetic analysis of the tenascin gene family: evidence of origin early in the chordate lineage

Background  

Tenascins are a family of glycoproteins found primarily in the extracellular matrix of embryos where they help to regulate cell proliferation, adhesion and migration. In order to learn more about their origins and relationships to each other, as well as to clarify the nomenclature used to describe them, the tenascin genes of the urochordate Ciona intestinalis, the pufferfish Tetraodon nigroviridis and Takifugu rubripes and the frog Xenopus tropicalis were identified and their gene organization and predicted protein products compared with the previously characterized tenascins of amniotes.     

A novel surface protein of Trichomonas vaginalis is regulated independently by low iron and contact with vaginal epithelial cells

Background  

Trichomonosis caused by Trichomonas vaginalis is the number one, non-viral sexually transmitted disease (STD) that affects more than 250 million people worldwide. Immunoglobulin A (IgA) has been implicated in resistance to mucosal infections by pathogens. No reports are available of IgA-reactive proteins and the role, if any, of this class of antibody in the control of this STD. The availability of an IgA monoclonal antibody (mAb) immunoreactive to trichomonads by whole cell (WC)-ELISA prompted us to characterize the IgA-reactive protein of T. vaginalis.     

Effect of light and temperature on monoterpenoid yield and composition in Satureja douglasii

Light intensity and day temperature were identified as principal modifying factors of monoterpenoid composition and yield in individuals of Satureja douglasii. The individuals represent compositional type and clinial patterns of infraspecific compositional variation. The lack of compositional interconversion confirms the tight genetic control of biosynthesis which results in these infraspecific patterns. There was marked influence by light intensity on monoterpenoid yield per leaf dry weight and by day temperature on yield per leaf. Low light intensity reduced leaf dry weight but had little effect on the amount of monoterpenoids per leaf whereas low day temperature increased both leaf weight and yield per leaf, compared to high light and day temperature effects. Day temperature modification of yield per leaf was related to modification of composition.     

Preliminary studies of monoterpenoid variability in Satureja douglasii

Monoterpenoid composition of samples from 10 populations of Satureja douglasii in a 250-ha area were analyzed in Spring 1974. Two distinct compositional types were found: Type A contained large amounts of limonene and carvone but very small quantites of piperitenone, piperitone, pulegone and isomenthone (3-oxy compounds), whereas Type B was essentially the reverse. This variation is attributed to a genotypic difference. The amounts of 3-oxy compounds varied greatly among the Type B populations. Increasing shade conditions were correlated with increased amounts of the more reduced compounds isomenthone and piperitone. Clonal lines were established from two Type B populations whose habitats represented extremes of sun and shade conditions. The two clonal lines, which had very different compositions in the field, produced similar oils under controlled conditions. Growth under different temperature regimes had little effect on composition. Developmental changes in composition implied the precursor-product relationships piperitenone→piperitone and pulegone→isomenthone. The data suggest that S douglasii monoterpenoid compositional patterns are significantly influenced by genetic and environmental factors (probably light intensity) as well as developmental processes.     

Extreme differences in rates of molecular evolution of foraminifera revealed by comparison of ribosomal DNA sequences and the fossil record

Foraminifera have one of the best known fossil records among the unicellular eukaryotes. However, the origin and phylogenetic relationships of the extant foraminiferal lineages are poorly understood. To test the current paleontological hypotheses on evolution of foraminifera, we sequenced about 1,000 base pairs from the 3' end of the small subunit rRNA gene (SSU rDNA) in 22 species representing all major taxonomic groups. Phylogenies were derived using neighbor- joining, maximum-parsimony, and maximum-likelihood methods. All analyses confirm the monophyletic origin of foraminifera. Evolutionary relationships within foraminifera inferred from rDNA sequences, however, depend on the method of tree building and on the choice of analyzed sites. In particular, the position of planktonic foraminifera shows important variations. We have shown that these changes result from the extremely high rate of rDNA evolution in this group. By comparing the number of substitutions with the divergence times inferred from the fossil record, we have estimated that the rate of rDNA evolution in planktonic foraminifera is 50 to 100 times faster than in some benthic foraminifera. The use of the maximum-likelihood method and limitation of analyzed sites to the most conserved parts of the SSU rRNA molecule render molecular and paleontological data generally congruent.      

Global transcriptional response of pig brain and lung to natural infection by Pseudorabies virus

Background  

Pseudorabies virus (PRV) is an alphaherpesviruses whose native host is pig. PRV infection mainly causes signs of central nervous system disorder in young pigs, and respiratory system diseases in the adult.     

Defining the healthy "core microbiome" of oral microbial communities

Background  

Most studies examining the commensal human oral microbiome are focused on disease or are limited in methodology. In order to diagnose and treat diseases at an early and reversible stage an in-depth definition of health is indispensible. The aim of this study therefore was to define the healthy oral microbiome using recent advances in sequencing technology (454 pyrosequencing).     

Mitochondrial heteroplasmy and DNA barcoding in Hawaiian <Emphasis Type="Italic">Hylaeus</Emphasis> (<Emphasis Type="Italic">Nesoprosopis</Emphasis>) bees (Hymenoptera: Colletidae)

Background  

The past several years have seen a flurry of papers seeking to clarify the utility and limits of DNA barcoding, particularly in areas such as species discovery and paralogy due to nuclear pseudogenes. Heteroplasmy, the coexistence of multiple mitochondrial haplotypes in a single organism, has been cited as a potentially serious problem for DNA barcoding but its effect on identification accuracy has not been tested. In addition, few studies of barcoding have tested a large group of closely-related species with a well-established morphological taxonomy. In this study we examine both of these issues, by densely sampling the Hawaiian Hylaeus bee radiation.     

alpha-Tocopherol and protein kinase C inhibition enhance platelet-derived nitric oxide release.

Platelet activation is tightly regulated by products of the endothelium and platelets including nitric oxide (NO). Excess vascular oxidative stress has been associated with impaired NO release, and antioxidant status has been shown to alter endothelium-derived NO bioactivity. Although physiological levels of a-tocopherol are known to inhibit platelet function, the effect of a-tocopherol on platelet NO release is unknown. Loading platelets with physiologic levels of a-tocopherol increased platelet NO production approximately 1.5-fold (Pa-tocopherol, platelet NO release increased 50% (Pa-Tocopherol-loaded platelets also produced 74% less superoxide as compared with control (Pa-tocopherol inhibited PKC-dependent eNOS phosphorylation as determined by immunoprecipitation. Lastly, platelets isolated from NOS3-deficient mice released 80% less superoxide as compared with control animals (P=0.011), and incubation of NOS III-deficient platelets with 500 mM a-tocopherol only caused a modest additional decrease in platelet superoxide release (NS). Thus, a-tocopherol appears to enhance platelet NO release both in vitro and in vivo through antioxidant- and PKC-dependent mechanisms.