The phylogeny of the ant tribe Formicini (Hymenoptera: Formicidae) with the description of a new genus

Abstract. The holarctic ant tribe Formicini is revised, the new genus Bajcaridris described, and possible phylogenetic relationships are discussed. The subgenus Iberoformica is synonymized with Formica. A synopsis, diagnosis and keys to the genera are provided.     

Molecular biology of bovine viral diarrhea virus

Bovine viral diarrhea viruses (BVDV) are arguably the most important viral pathogen of ruminants worldwide and can cause severe economic loss. Clinical symptoms of the disease caused by BVDV range from subclinical to severe acute hemorrhagic syndrome, with the severity of disease being strain dependent. These viruses are classified as members of the Pestivirus genus of the Flaviviridae. BVDV are considered primarily a pathogen of cattle but can infect most ruminant species. The virus particle consists of a lipid bilayer membrane surrounding the encapsidated genomic RNA. Inserted in the outer membrane are two virus-encoded glycoproteins that contain the major antigenic determinants of the virus as well as receptor binding and cell fusion functions. A third glycoprotein is weakly associated with the virion, but also possesses unique features that play important roles in suppression of innate immunity. The viral proteins are encoded in a single, large open reading frame. The viral proteins are proteolytically cleaved from the polyprotein by different proteases. The structural proteins are processed by cellular signal peptidases while the processing of the nonstructural proteins is by the viral serine protease. The virus is assembled and matures in the endoplasmic reticulum and golgi bodies of the cell. The virus is released via exocytosis, where viral proteins are not exposed on the surface of the cell.     

Staphylococcus aureus SH1000 and 8325‐4: comparative genome sequences of key laboratory strains in staphylococcal research

Aims: To provide comparative genome sequence data for two related model strains of Staphylococcus aureus (SH1000 and 8325‐4) that are used extensively in laboratory research. Methods and Results: Comparative genome sequencing was used to identify genetic differences between Staph. aureus SH1000 and the fully genome‐sequenced ancestral strain, Staph. aureus NCTC 8325. PCR amplification and DNA sequencing were employed to determine which of the genetic polymorphisms identified were also present in Staph. aureus 8325‐4, a direct derivative of 8325 and the parent strain of SH1000. Aside from known genetic differences between these strains, Staph. aureus SH1000 harboured 15 single‐nucleotide polymorphisms compared with 8325 (of which 12 were also found in 8325‐4), and a 63‐bp deletion upstream of the spa gene not present in either 8325 or 8325‐4. Conclusions: Staphylococcus aureus SH1000 and 8325‐4 contain a number of genetic polymorphisms relative to the progenitor strain of the lineage (8325) and to each other. Significance and Impact of the Study: The comparative genome sequences of SH1000 and 8325‐4 presented here define the genotypes of two key strains in staphylococcal laboratory research and reveal genetic polymorphisms that may impact their phenotypic properties.     

Projected climate and land use change alter western blacklegged tick phenology,seasonal host‐seeking suitability and human encounter risk in California

Global environmental change is having profound effects on the ecology of infectious disease systems, which are widely anticipated to become more pronounced under future climate and land use change. Arthropod vectors of disease are particularly sensitive to changes in abiotic conditions such as temperature and moisture availability. Recent research has focused on shifting environmental suitability for, and geographic distribution of, vector species under projected climate change scenarios. However, shifts in seasonal activity patterns, or phenology, may also have dramatic consequences for human exposure risk, local vector abundance and pathogen transmission dynamics. Moreover, changes in land use are likely to alter human–vector contact rates in ways that models of changing climate suitability are unlikely to capture. Here we used climate and land use projections for California coupled with seasonal species distribution models to explore the response of the western blacklegged tick (Ixodes pacificus), the primary Lyme disease vector in western North America, to projected climate and land use change. Specifically, we investigated how environmental suitability for tick host‐seeking changes seasonally, how the magnitude and direction of changing seasonal suitability differs regionally across California, and how land use change shifts human tick‐encounter risk across the state. We found vector responses to changing climate and land use vary regionally within California under different future scenarios. Under a hotter, drier scenario and more extreme land use change, the duration and extent of seasonal host‐seeking activity increases in northern California, but declines in the south. In contrast, under a hotter, wetter scenario seasonal host‐seeking declines in northern California, but increases in the south. Notably, regardless of future scenario, projected increases in developed land adjacent to current human population centers substantially increase potential human–vector encounter risk across the state. These results highlight regional variability and potential nonlinearity in the response of disease vectors to environmental change.     

TMEM106B p.T185S regulates TMEM106B protein levels: implications for frontotemporal dementia

Frontotemporal lobar degeneration (FTLD) is the second leading cause of dementia in individuals under age 65. In many patients, the predominant pathology includes neuronal cytoplasmic or intranuclear inclusions of ubiquitinated TAR DNA binding protein 43 (FTLD‐TDP). Recently, a genome‐wide association study identified the first FTLD‐TDP genetic risk factor, in which variants in and around the TMEM106B gene (top SNP rs1990622) were significantly associated with FTLD‐TDP risk. Intriguingly, the most significant association was in FTLD‐TDP patients carrying progranulin (GRN) mutations. Here, we investigated to what extent the coding variant, rs3173615 (p.T185S) in linkage disequilibrium with rs1990622, affects progranulin protein (PGRN) biology and transmembrane protein 106 B (TMEM106B) regulation. First, we confirmed the association of TMEM106B variants with FTLD‐TDP in a new cohort of GRN mutation carriers. We next generated and characterized a TMEM106B‐specific antibody for investigation of this protein. Enzyme‐linked immunoassay analysis of progranulin protein levels showed similar effects upon T185 and S185 TMEM106B over‐expression. However, over‐expression of T185 consistently led to higher TMEM106B protein levels than S185. Cycloheximide treatment experiments revealed that S185 degrades faster than T185 TMEM106B, potentially due to differences in N‐glycosylation at residue N183. Together, our results provide a potential mechanism by which TMEM106B variants lead to differences in FTLD‐TDP risk.

     

Synthesis and evaluation of the antimalarial,anticancer, and caspase 3 activities of tetraoxane dimers

The synthesis of a range of mono spiro and dispiro 1,2,4,5-tetraoxane dimers is described. Selected molecules were examined in in vitro assays to determine their antimalarial and anticancer potential. Our studies reveal that several molecules possess potent nanomolar antimalarial and single digit micromolar antiproliferative IC₅₀s versus colon (HT29-AK and leukemia (HL60) cell lines.