Live attenuated herpes simplex virus 2 glycoprotein E deletion mutant as a vaccine candidate defective in neuronal spread

A herpes simplex virus 2 (HSV-2) glycoprotein E deletion mutant (gE2-del virus) was evaluated as a replication-competent, attenuated live virus vaccine candidate. The gE2-del virus is defective in epithelial cell-to-axon spread and in anterograde transport from the neuron cell body to the axon terminus. In BALB/c and SCID mice, the gE2-del virus caused no death or disease after vaginal, intravascular, or intramuscular inoculation and was 5 orders of magnitude less virulent than wild-type virus when inoculated directly into the brain. No infectious gE2-del virus was recovered from dorsal root ganglia (DRG) after multiple routes of inoculation; however, gE2-del DNA was detected by PCR in lumbosacral DRG at a low copy number in some mice. Importantly, no recurrent vaginal shedding of gE2-del DNA was detected in immunized guinea pigs. Intramuscular immunization outperformed subcutaneous immunization in all parameters evaluated, although individual differences were not significant, and two intramuscular immunizations were more protective than one. Immunized animals had reduced vaginal disease, vaginal titers, DRG infection, recurrent genital lesions, and recurrent vaginal shedding of HSV-2 DNA; however, protection was incomplete. A combined modality immunization using live virus and HSV-2 glycoprotein C and D subunit antigens in guinea pigs did not totally eliminate recurrent lesions or recurrent vaginal shedding of HSV-2 DNA. The gE2-del virus used as an immunotherapeutic vaccine in previously HSV-2-infected guinea pigs greatly reduced the frequency of recurrent genital lesions. Therefore, the gE2-del virus is safe, other than when injected at high titer into the brain, and is efficacious as a prophylactic and immunotherapeutic vaccine.     

Evolution of cytochrome P-450 proteins [published erratum appears in Mol Biol Evol 1988 Mar;5(2):199]

Thirty-four cytochrome P-450 sequences from one bacterial and six vertebrate species have been aligned with the aid of a computer alignment algorithm. Phylogenetic trees were constructed using the unweighted-pair-group and neighbor-joining methods. The two trees differed at only a single branch point near the base of the tree. The cytochrome P-450 superfamily of proteins clustered into eight families and contained 16 gene-duplication events. The first gene duplication occurred approximately 1,360 Myr before the present (Mybp) and gave rise to cytochrome P-450s found in two different cellular organelles, the mitochondria and the endoplasmic reticulum. Both groups utilize cholesterol or its metabolites as substrates, implying that cholesterol existed greater than 1,360 Mybp. The fourth gene duplication (approximately 900 Mybp) gave rise to the drug-metabolizing P-450s. These proteins aid in the detoxification of foreign chemicals, as opposed to the metabolism of endogenous compounds. The importance of the capacity to metabolize drugs is reflected in 11 further gene duplications occurring in this lineage. The first occurred approximately 800 Mybp and gave rise to the two major P-450 families, the phenobarbital and 3-methylcholanthrene families. An apparent increase in the rate of cytochrome P-450 evolution is noted between the bird-mammal divergence (300 Mybp) and the mammalian radiation (75 Mybp).      

Cytokinins act directly on lateral root founder cells to inhibit root initiation

In Arabidopsis thaliana, lateral roots are formed from root pericycle cells adjacent to the xylem poles. Lateral root development is regulated antagonistically by the plant hormones auxin and cytokinin. While a great deal is known about how auxin promotes lateral root development, the mechanism of cytokinin repression is still unclear. Elevating cytokinin levels was observed to disrupt lateral root initiation and the regular pattern of divisions that characterizes lateral root development in Arabidopsis. To identify the stage of lateral root development that is sensitive to cytokinins, we targeted the expression of the Agrobacterium tumefaciens cytokinin biosynthesis enzyme isopentenyltransferase to either xylem-pole pericycle cells or young lateral root primordia using GAL4-GFP enhancer trap lines. Transactivation experiments revealed that xylem-pole pericycle cells are sensitive to cytokinins, whereas young lateral root primordia are not. This effect is physiologically significant because transactivation of the Arabidopsis cytokinin degrading enzyme cytokinin oxidase 1 in lateral root founder cells results in increased lateral root formation. We observed that cytokinins perturb the expression of PIN genes in lateral root founder cells and prevent the formation of an auxin gradient that is required to pattern lateral root primordia.     

Agriculture as matchmaker of an unexpected mutualism: Great bustard disperses and enhances emergence of domestic olive seeds

By changing the habitats and altering plant traits, agriculture has severely disrupted many plant–animal mutualisms. Interestingly, however, the intensification of agricultural practices could also facilitate mutualistic relationships between species with naturally mismatching phenotypes. We illustrate the potential of the great bustard (Otis tarda), a large steppe bird, as disperser of domestic olive (Olea europaea) seeds, originally a forest species. In an area of southwestern Spain, 30% of bustard faeces included olive stones (from 1 to 13). Only 1.7% of the bustard-ingested olive seeds were broken. Moreover, using a sowing experiment, we show bustard ingestion enhanced seedling emergence, which reached 8.8%, 3.4% and 0.0% for bustard-ingested, hand-depulped, and control seeds, respectively. As expected for Mediterranean habitats, seedling mortality was very high in the first summer for all seed treatments. In 6 out of 19 non-plowed patches within our study area, we found olive saplings of different ages likely to emerge from bustard-dispersed seeds. Given the large size of domestic olive fruits, bustards are among the few local animals able to disperse their seeds and thus to assist in the forestation of field boundaries and abandoned lands. Paradoxically, because bustards are rather restricted to open habitats, their success in shaping the habitat (i.e., ‘planting’ olive trees) could lead to their own removal from the resulting forested landscape.     

Loss of Allograft Inflammatory Factor-1 Ameliorates Experimental Autoimmune Encephalomyelitis by Limiting Encephalitogenic CD4 T-Cell Expansion

Experimental autoimmune encephalomyelitis (EAE), an animal model of human multiple sclerosis (MS), is mediated by myelin-specific autoreactive T cells that cause inflammation and demyelination in the central nervous system (CNS), with significant contributions from activated microglia and macrophages. The molecular bases for expansion and activation of these cells, plus trafficking to the CNS for peripheral cells, are not fully understood. Allograft inflammatory factor-1 (Aif-1) (also known as ionized Ca²⁺ binding adapter-1 [Iba-1]) is induced in leukocytes in MS and EAE; here we provide the first assessment of Aif-1 function in this setting. After myelin oligodendrocyte glycoprotein peptide (MOG_35–55) immunization, Aif-1–deficient mice were less likely than controls to develop EAE and had less CNS leukocyte infiltration and demyelination; their spinal cords contained fewer CD4 T cells and microglia and more CD8 T cells. These mice also showed significantly less splenic CD4 T-cell expansion and activation, plus decreased proinflammatory cytokine expression. These findings identify Aif-1 as a potent molecule that promotes expansion and activation of CD4 T cells, plus elaboration of a proinflammatory cytokine milieu, in MOG_35–55-induced EAE and as a potential therapeutic target in MS.     

Modeling the geographic distribution of Myocastor coypus (Mammalia,Rodentia) in Brazil: establishing priority areas for monitoring and an alert about the risk of invasion

ABSTRACT

Myocastor coypus

is a large semi-aquatic rodent ranked as one of the 100 most invasive species in the world. In Brazil, few ecological studies have been proposed to understand the relationship of this species with the environment. To date, drivers that facilitate its establishment in new areas remain unknown. However, it is generally accepted that the natural distribution of this species is limited to far southern Brazil. The present study aimed to understand the geographic distribution of M. coypus and indicate areas of greater risk of establishment based on bioclimatic predictors and a surveillance map. We observed that M. coypus suitability and risk assessment areas are restricted to the southeastern and southern regions of Brazil and that anthropogenic landscape modifications are an adequate variable to explain the occurrence of the species. Due to the environmental impacts caused by this species, monitoring in environments where it has been introduced is required. The model used herein presented efficient applicability and fit for Brazil. Preventive actions and the management of M. coypus in predicted regions prior to its establishment are recommended.     

Functional characterization of the neurodepressing hormone in the crayfish

The effect of the neurodepressing hormone (NDH) was studied on different identified motoneurons in the abdominal ganglia of the crayfish Procambarus bouvieri (Ortmann). Although differences in sensitivity were apparent, all the neurons tested responded to NDH with a reduction in spontaneous firing rate, which lasted as long as NDH was present, and, depending on the concentration and time od action of the hormone, for even longer periods. NDH activity was determined in the various parts of the central nervous system of the crayfish, being highest in the eyestalk, gradually diminishing away from the eyestalk, with a cephalo-caudal gradient, being lowest in the abdominal ganglia. High levels of NDH activity were detected in the blood. After eyestalk ablation, NDH concentrations steadily diminishes, in the blood and central nervous systems, until virtually disappearing after 4 days; from day 5 onwards, the activity is recovered up to its original levels. NDH synthesis takes place with a time constant of approximately 3 hr in cultured segments of central nervous system, being highest in the eyestalk.     

Effect of a Treatment with Naphthaleneacetic Acid on the Arrangement of Lateral Roots in Onion (Allium cepa L): General Pattern and Coordination between Ranks

Lateral roots in Allium cepa arise in longitudinal rows opposite the protoxylem poles of adventitious roots. The number, spacing within ranks and positional relationship to laterals in different ranks were analysed in control roots and those treated with an auxin (α-naphthaleneacetic acid). Treatment increased numbers of laterals per rank and distributed the more evenly in all ranks. Laterals of control roots were concentrated in two neighbouring ranks. Auxin-treated roots showed a more regular distribution of laterals between ranks and close spacing of laterals along each rank. Comparisons with theoretical random distributions suggest a dispersed spacing model for lateral root arrangement with mutual repulsion between successive lateral roots within each rank both in control and auxintreated roots. On the other hand, there is some interaction between laterals in different ranks in 0.1 mM NAA-treated roots.