Views,landmarks, and routes: how do desert ants negotiate an obstacle course?

The Australian desert ant Melophorus bagoti often follows stereotypical routes through a cluttered landscape containing both distant panoramic views and obstacles (plants) to navigate around. We created an artificial obstacle course for the ants between a feeder and their nest. Landmarks comprised natural objects in the landscape such as logs, branches, and tussocks. Many ants travelled stereotypical routes home through the obstacle course in training, threading repeatedly the same gaps in the landmarks. Manipulations altering the relations between the landmarks and the surrounding panorama, however, affected the routes in two major ways. Both interchanging the positions of landmarks (transpositions) and displacing the entire landmark set along with the starting position of the ants (translations) (1) reduced the stereotypicality of the route, and (2) increased turns and meanders during travel. The ants might have used the entire panorama in view-based travel, or the distal panorama might prime the identification and use of landmarks en route. Despite the large data set, both options (not mutually exclusive) remain viable.     

Glands of the eyelids of rhesus monkeys (Macaca mulatta)

The various glands of rhesus monkey eyelids and human eyelids are similar. Numerous modified sebaceous glands are located along the tarsus. These conform with the meibomian glands, while typical sebaceous glands associated with the hair follicles of the lashes are consistent with the glands of Zeis. Lobules of accessory lacrimal tissue, corresponding to the glands of Krause and Wolfring, are located in the conjunctiva of the fornix and along the orbital border of the tarsal plate. Goblet cells are plentiful in the mucosa of the palpebral and bulbar conjunctiva, and along the lid margin are the sweat glands of Moll.     

Immunoelectrophoretic characterization of the ADP/ATP carrier from heart, kidney, and liver

Earlier studies gave an indication for an organ specificity of the ADP/ATP carrier. We used a modified charge-shift crossed immunoelectrophoresis for a more precise immunochemical characterization of this detergent-solubilized hydrophobic membrane protein. Immunological differences between the carrier protein from heart, kidney, and liver were demonstrated by a different electrophoretic migration of the three ligand-protein complexes in the first dimension and a distinct staining intensity, sharpness, and shape of the precipitates in the second dimension. However, the antibodies against the heart and kidney protein showed a cross-reactivity between the three antigens. The results are consistent with the view that the ADP/ATP carrier has organ-specific antigenic determinants although there is a partial identity between the carrier proteins from heart, kidney, and liver.     

Neutron RBE for primate spinal cord treated with clinical regimens.

The RBEs of high-energy neutrons given in 9 or 12 fractions for cervical spinal cord injury in rhesus monkeys was determined using photons at 2.2 Gy per fraction as the reference radiation. Because the dose-response functions were not parallel, the RBE was not constant but rather increased with dose or, equivalently, with the probability of myelopathy. This required the development of a novel method of determining the RBE versus level of response. The RBE is presented as a function of probability of myelopathy from 0.1 to 99%. At a 50% incidence of myelopathy, the RBE (+/- 1 SE) was 5.22 +/- 0.15. A difference in the histopathology of lesions induced by photon and neutron treatments was observed.     

Cleavage specificity of purified recombinant hepatitis A virus 3C proteinase on natural substrates.

Hepatitis A virus (HAV) 3C proteinase expressed in Escherichia coli was purified to homogeneity, and its cleavage specificity towards various parts of the viral polyprotein was analyzed. Intermolecular cleavage of the P2-P3 domain of the HAV polyprotein gave rise to proteins 2A, 2B, 2C, 3ABC, and 3D, suggesting that in addition to the primary cleavage site, all secondary sites within P2 as well as the 3C/3D junction are cleaved by 3C. 3C-mediated processing of the P1-P2 precursor liberated 2A and 2BC, in addition to the structural proteins VP0, VP3, and VP1-2A and the respective intermediate products. A clear dependence on proteinase concentration was found for most cleavage sites, possibly reflecting the cleavage site preference of 3C. The most efficient cleavage occurred at the 2A/2B and 2C/3A junctions. The electrophoretic mobility of processing product 2B, as well as cleavage of the synthetic peptide KGLFSQ*AKISLFYT, suggests that the 2A/2B junction is located at amino acid position 836/837 of the HAV polyprotein. Furthermore, using suitable substrates we obtained evidence that sites VP3/VP1 and VP1/2A are alternatively processed by 3C, leading to either VP1-2A or to P1 and 2A. The results with regard to intermolecular cleavage by purified 3C were confirmed by the product pattern derived from cell-free expression and intramolecular processing of the entire polyprotein. We therefore propose that polyprotein processing of HAV relies on 3C as the single proteinase, possibly assisted by as-yet-undetermined viral or host cell factors and presumably controlled in a concentration-dependent fashion.     

Interspecies gene transfer provides soybean resistance to a fungal pathogen

Fungal pathogens pose a major challenge to global crop production. Crop varieties that resist disease present the best defence and offer an alternative to chemical fungicides. Exploiting durable nonhost resistance (NHR) for crop protection often requires identification and transfer of NHR‐linked genes to the target crop. Here, we identify genes associated with NHR of Arabidopsis thaliana to Phakopsora pachyrhizi, the causative agent of the devastating fungal disease called Asian soybean rust. We transfer selected Arabidopsis NHR‐linked genes to the soybean host and discover enhanced resistance to rust disease in some transgenic soybean lines in the greenhouse. Interspecies NHR gene transfer thus presents a promising strategy for genetically engineered control of crop diseases.     

Different activities of the largest subunit of replication protein A cooperate during SV40 DNA replication

Replication protein A (RPA) is a stable heterotrimeric complex consisting of p70, p32 and p14 subunits. The protein plays a crucial role in SV40 minichromosome replication. Peptides of p70 representing interaction sites for the smaller two subunits, DNA as well as the viral initiator protein large T-antigen (Tag) and the cellular DNA polymerase alpha-primase (Pol) all interfered with the replication process indicating the importance of the different p70 activities in this process. Inhibition by the peptide disrupting protein-protein interactions was observed only during the pre-initiation stage prior to primer synthesis, suggesting the formation of a stable initiation complex between RPA, Tag and Pol at the primer end.     

Genetics of osteopontin in patients with chronic kidney disease: The German Chronic Kidney Disease study

Osteopontin (OPN), encoded by SPP1, is a phosphorylated glycoprotein predominantly synthesized in kidney tissue. Increased OPN mRNA and protein expression correlates with proteinuria, reduced creatinine clearance, and kidney fibrosis in animal models of kidney disease. But its genetic underpinnings are incompletely understood. We therefore conducted a genome-wide association study (GWAS) of OPN in a European chronic kidney disease (CKD) population. Using data from participants of the German Chronic Kidney Disease (GCKD) study (N = 4,897), a GWAS (minor allele frequency [MAF]≥1%) and aggregated variant testing (AVT, MAF<1%) of ELISA-quantified serum OPN, adjusted for age, sex, estimated glomerular filtration rate (eGFR), and urinary albumin-to-creatinine ratio (UACR) was conducted. In the project, GCKD participants had a mean age of 60 years (SD 12), median eGFR of 46 mL/min/1.73m² (p25: 37, p75: 57) and median UACR of 50 mg/g (p25: 9, p75: 383). GWAS revealed 3 loci (p<5.0E-08), two of which replicated in the population-based Young Finns Study (YFS) cohort (p<1.67E-03): rs10011284, upstream of SPP1 encoding the OPN protein and related to OPN production, and rs4253311, mapping into KLKB1 encoding prekallikrein (PK), which is processed to kallikrein (KAL) implicated through the kinin-kallikrein system (KKS) in blood pressure control, inflammation, blood coagulation, cancer, and cardiovascular disease. The SPP1 gene was also identified by AVT (p = 2.5E-8), comprising 7 splice-site and missense variants. Among others, downstream analyses revealed colocalization of the OPN association signal at SPP1 with expression in pancreas tissue, and at KLKB1 with various plasma proteins in trans, and with phenotypes (bone disorder, deep venous thrombosis) in human tissue. In summary, this GWAS of OPN levels revealed two replicated associations. The KLKB1 locus connects the function of OPN with PK, suggestive of possible further post-translation processing of OPN. Further studies are needed to elucidate the complex role of OPN within human (patho)physiology.     

Implicit power motivation moderates men's testosterone responses to imagined and real dominance success

This study tested the hypothesis that implicit power motivation moderates individuals' testosterone responses to the anticipated success in and actual outcome of a dominance contest. Salivary testosterone levels were assessed in 42 male students at the beginning of the study, after they had imagined a success in an ensuing power contest, and immediately after the contest had taken place. Contest outcome (winning or losing against a competitor on a speed-based task) was varied experimentally. Participants' power motive was assessed with a picture-story exercise, in which an assertive, personalized (p Power) component was distinguished from an altruistic, socialized (s Power) component. In contrast to all other participants, individuals high only in p Power (a) had elevated testosterone after imagining a success in a subsequent dominance contest and (b) continued to have high testosterone levels after actually winning, but not after losing, the contest.