The voltage-gated calcium channel UNC-2 is involved in stress-mediated regulation of tryptophan hydroxylase

Migraine is an episodic pain disorder whose pathophysiology is related to deficiency of serotonin signaling and abnormal function of the P/Q-type calcium channel, CACNA1A. Because the relationship of the CACNA1A channel to serotonin signaling is unknown and potentially of therapeutic interest we have used genetic analysis of the Caenorhabditis elegans ortholog of this calcium channel, UNC-2, to help identify candidate downstream effectors of the human channel. By genetic dissection of the lethargic mutant phenotype of unc-2, we have established an epistasis pathway showing that UNC-2 function antagonizes a transforming growth factor (TGF)-beta pathway influencing movement rate. This same UNC-2/TGF-beta pathway is required for accumulation of normal serotonin levels and stress-induced modulation of tryptophan hydroxylase (tph) expression in the serotonergic chemosensory ADF neurons, but not the NSM neurons. We also show that transgenic expression of the migraine-associated Ca2+ channel, CACNA1A, in unc-2 animals can functionally substitute for UNC-2 in stress-activated regulation of tph expression. The demonstration that these evolutionarily related channels share a conserved ability to modulate tph expression through their effects on TGF-beta signaling provides the first specific example of how CACNA1A function may influence levels of the critical migraine neurotransmitter serotonin.     

Lipid rafts in cytokine signaling

Lipid rafts are established as critical structures for a variety of cellular processes, including immune cell activation. Beyond their importance for initial immune cell activation at the immunological synapse, lipid rafts are now also being recognized as important sites for cytokine and growth factor signal transduction, both in immune cells as part of secondary regulatory processes, and in non-immune cells. This review summarizes current knowledge regarding the roles of rafts in cytokine signaling and emphasizes the need for measures to better standardize the study of rafts.     

Serosurvey of free-ranging Amur tigers in the Russian Far East

Wild Amur tigers (Panthera tigris altaica, n=44) from the Russian Far East were tested for antibodies to feline leukemia virus, feline corona virus (FCoV), feline immunodeficiency virus, feline parvovirus (FPV), canine distemper virus (CDV), Toxoplasma gondii, and Bartonella henselae. Antibodies to FCoV, CDV, FPV, and T. gondii were detected in 43, 15, 68, and 42% of tigers, respectively. No differences were detected in antibody prevalence estimates between tigers captured as part of a research program and those captured to mitigate human-tiger conflicts. Domestic dogs (Canis familiaris) were tested as a potential source for CDV; 16% were vaccinated against CDV and 58% of unvaccinated dogs were antibody positive for CDV. A high percentage of tigers were exposed to potential pathogens that could affect the survival of this species. We recommend continued monitoring of wild tigers throughout Asia, development of standardized sampling and postmortem examination procedures, and additional research to better understand potential domestic and wild animal sources for these pathogens.     

Long-Lasting Immune Protection and Other Epidemiological Findings after Chikungunya Emergence in a Cambodian Rural Community,April 2012

The East/Central/South African genotype of Chikungunya virus with the E1-A226V mutation emerged in 2011 in Cambodia and spread in 2012. An outbreak of 190 cases was documented in Trapeang Roka, a rural village. We surveyed 425 village residents within 3–4 weeks after the outbreak, and determined the sensitivity and specificity of case definitions and factors associated with infection by CHIKV. Self-reported clinical presentation consisted mostly of fever, rash and arthralgia. The presence of all three clinical signs or symptoms was identified as the most sensitive (67%) and specific (84%) self-reported diagnostic clinical indicator compared to biological confirmation by MAC-ELISA or RT-PCR used as a reference. Having an indoor occupation was associated with lower odds of infection compared with people who remained at home (adjOR 0.32, 95%CI 0.12–0.82). In contrast with findings from outbreaks in other settings, persons aged above 40 years were less at risk of CHIKV infection, likely reflecting immune protection acquired when Chikungunya circulated in Cambodia before the Khmer Rouge regime in 1975. In view of the very particular history of Cambodia, our epidemiological data from Trapeang Roka are the first to support the persistence of CHIKV antibodies over a period of 40 years.     

Influence of antimicrobial feed additives on broiler commensal posthatch gut microbiota development and performance

The effects of avilamycin, zinc bacitracin, and flavophospholipol on broiler gut microbial community colonization and bird performance in the first 17 days posthatch were investigated. Significant differences in gut microbiota associated with gut section, dietary treatment, and age were identified by terminal restriction fragment length polymorphism (T-RFLP), although no performance-related differences between dietary treatments were detected. Similar age-related shifts in the gut microbiota were identified regardless of diet but varied between the ilea and ceca. Interbird variabilities in ileal bacterial communities were reduced (3 to 7 days posthatch) in chicks fed with feed containing antimicrobial agents. Avilamycin and flavophospholipol had the most consistent effect on gut microbial communities. Operational taxonomic units (OTU) linked to changes in gut microbiota in birds on antimicrobial-supplemented diets were characterized and identified. Some OTUs could be identified to the species level; however, the majority could be only tentatively classified to the genus, family, order, or domain level. OTUs 140 to 146 (Lachnospiraceae), OTU 186/188 (Lactobacillus johnsonii), OTU 220 (Lachnospiraceae), OTUs 284 to 288 (unclassified bacterial spp. or Ruminococcaceae), OTU 296/298 (unclassified bacterium or Clostridiales), and OTU 480/482 (Oxalobacteraceae) were less prevalent in the guts of chicks fed antimicrobial-supplemented diets. OTU 178/180 (Lactobacillus crispatus), OTU 152 (Lactobacillus reuteri or unclassified Clostridiales), OTU 198/200 (Subdoligranulum spp.), and OTU 490/492 (unclassified bacterium or Enterobacteriaceae) were less prevalent in the gut of chicks raised on the antimicrobial-free diet. The identification of key bacterial species influenced by antimicrobial-supplemented feed immediately posthatch may assist in the formulation of diets that facilitate beneficial gut microbial colonization and, hence, the development of alternatives to current antimicrobial agents in feed for sustainable poultry production.     

Influence of ploidy level on morphology,growth and drought susceptibility in <Emphasis Type="Italic">Spathiphyllum wallisii</Emphasis>

In this study, we analysed morphological, anatomical and physiological effects of polyploidisation in Spathiphyllum wallisii in order to evaluate possible interesting advantages of polyploids for ornamental breeding. Stomatal density was negatively correlated with increased ploidy level. Stomatal size increased in polyploids. Tetraploid Spathiphyllum plants had more ovate and thicker leaves. The inflorescence of tetraploids had a more ovate and thicker spathum, a more cylindrical spadix and a thicker but shorter flower stalk. Biomass production of the tetraploids was reduced, as expressed by lower total dry weights, and tetraploids produced fewer shoots and leaves compared with their diploid progenitors. Furthermore, tetraploid Spathiphyllum plants were more resistant to drought stress compared with diploid plants. After 15 days of drought stress, diploids showed symptoms of wilting, while the tetraploids showed almost no symptoms. Further, measurements of stomatal resistance, leaf water potential, relative water content and proline content indicated that the tetraploid genotypes were more resistant to drought stress compared with the diploids.     

Using haplotypes to monitor the migration of fall armyworm (Lepidoptera: Noctuidae) corn-strain populations from Texas and Florida

Fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), infestations in most of North America north of Mexico arise from annual migrations of populations that overwinter in southern Texas and Florida. A comparison of the cytochrome oxidase I haplotype profiles within the fall armyworm corn-strain, the subgroup that preferentially infests corn (Zea mays L.) and sorghum (Sorghum vulgare Pers.), identified significant differences in the proportions of certain haplotypes between the Texas and Florida populations. These proportional differences were preserved as the populations migrated, providing a molecular metric by which the source of a migrant population could be identified. The migratory pattern derived from this method for several southeastern states was shown to be consistent with predictions based on analysis of historical agricultural and fall armyworm infestation data. These results demonstrate the utility of haplotype proportions to monitor fall armyworm migration, and they also introduce a potential method to predict the severity of cotton crop infestations in the short term.     

Enhancing Antibody Fc Heterodimer Formation through Electrostatic Steering Effects: APPLICATIONS TO BISPECIFIC MOLECULES AND MONOVALENT IgG

Naturally occurring IgG antibodies are bivalent and monospecific. Bispecific antibodies having binding specificities for two different antigens can be produced using recombinant technologies and are projected to have broad clinical applications. However, co-expression of multiple light and heavy chains often leads to contaminants and pose purification challenges. In this work, we have modified the CH3 domain interface of the antibody Fc region with selected mutations so that the engineered Fc proteins preferentially form heterodimers. These novel mutations create altered charge polarity across the Fc dimer interface such that coexpression of electrostatically matched Fc chains support favorable attractive interactions thereby promoting desired Fc heterodimer formation, whereas unfavorable repulsive charge interactions suppress unwanted Fc homodimer formation. This new Fc heterodimer format was used to produce bispecific single chain antibody fusions and monovalent IgGs with minimal homodimer contaminants. The strategy proposed here demonstrates the feasibility of robust production of novel Fc-based heterodimeric molecules and hence broadens the scope of bispecific molecules for therapeutic applications.     

Calcium-binding proteins and development

The known roles for calcium-binding proteins in developmental signaling pathways are reviewed. Current information on the calcium-binding characteristics of three classes of cell-surface developmental signaling proteins (EGF-domain proteins, cadherins and integrins) is presented together with an overview of the intra-cellular pathways downstream of these surface receptors. The developmental roles delineated to date for the universal intracellular calcium sensor, calmodulin, and its targets, and for calcium-binding regulators of the cytoskeleton are also reviewed.© Kluwer Academic Publishers     

Disruption of FEM1C-W gene in zebra finch: evolutionary insights on avian ZW genes

Sex chromosome genes control sex determination and differentiation, but the mechanisms of sex determination in birds are unknown. In this study, we analyzed the gene FEM1C which is highly conserved from Caenorhabditis elegans to higher vertebrates and interacts with the sex determining pathway in C. elegans. We found that FEM1C is located on the Z and W chromosome of zebra finches and probably other Passerine birds, but shows only Z linkage in other avian orders. In the zebra finch, FEM1C-W is degraded because of a point mutation and possibly because of loss of the first exon containing the start methionine. Thus, FEM1C-W appears to have degenerated or been lost from most bird species. FEM1C-Z is expressed in a cytoplasmic location in zebra finch fibroblast cells, as in C. elegans. FEM1C represents an interesting example of evolutionary degradation of a W chromosome gene.