Body mass and hibernation microclimate may predict bat susceptibility to white‐nose syndrome

In multihost disease systems, differences in mortality between species may reflect variation in host physiology, morphology, and behavior. In systems where the pathogen can persist in the environment, microclimate conditions, and the adaptation of the host to these conditions, may also impact mortality. White‐nose syndrome (WNS) is an emerging disease of hibernating bats caused by an environmentally persistent fungus, Pseudogymnoascus destructans. We assessed the effects of body mass, torpid metabolic rate, evaporative water loss, and hibernaculum temperature and water vapor deficit on predicted overwinter survival of bats infected by P. destructans. We used a hibernation energetics model in an individual‐based model framework to predict the probability of survival of nine bat species at eight sampling sites across North America. The model predicts time until fat exhaustion as a function of species‐specific host characteristics, hibernaculum microclimate, and fungal growth. We fit a linear model to determine relationships with each variable and predicted survival and semipartial correlation coefficients to determine the major drivers in variation in bat survival. We found host body mass and hibernaculum water vapor deficit explained over half of the variation in survival with WNS across species. As previous work on the interplay between host and pathogen physiology and the environment has focused on species with narrow microclimate preferences, our view on this relationship is limited. Our results highlight some key predictors of interspecific survival among western bat species and provide a framework to assess impacts of WNS as the fungus continues to spread into western North America.     

Evolutionary history of rat‐borne Bartonella: the importance of commensal rats in the dissemination of bacterial infections globally

Emerging pathogens that originate from invasive species have caused numerous significant epidemics. Some bacteria of genus Bartonella are rodent‐borne pathogens that can cause disease in humans and animals alike. We analyzed gltA sequences of 191 strains of rat‐associated bartonellae from 29 rodent species from 17 countries to test the hypotheses that this bacterial complex evolved and diversified in Southeast Asia before being disseminated by commensal rats Rattus rattus (black rat) and Rattus norvegicus (Norway rat) to other parts of the globe. The analysis suggests that there have been numerous dispersal events within Asia and introductions from Asia to other regions, with six major clades containing Southeast Asian isolates that appear to have been dispersed globally. Phylogeographic analyses support the hypotheses that these bacteria originated in Southeast Asia and commensal rodents (R. rattus and R. norvegicus) play key roles in the evolution and dissemination of this Bartonella complex throughout the world.     

Effect of soil volume and plant density on mycorrhizal infection and growth response

Summary The effect of soil volume and plant density on mycorrhizal infection and growth response was studied with onion. There was a significant negative correlation between percentage vesicular-arbuscular mycorrhizal infection and root density. The growth response due to mycorrhiza decreased when less soil was available for the plant. The root: shoot ratio decreased with increasing plant density in both mycorrhizal and non-mycorrhizal plants. Pot size did not affect the root: shoot ratio.     

Tartrate-resistant acid phosphatase (Acp 5): identification in diverse human tissues and dendritic cells.

Histochemical demonstration of tartrate-resistant acid phosphatase (TRAP) is used for the specific identification of osteoclasts. The enzyme, which we have shown to be critical for normal bone development in mice, is also characteristic of monohistiocytes, including alveolar macrophages, and is associated with diverse pathological conditions such as Gaucher's disease and hairy cell leukemia. TRAP activity is enhanced in serum when bone resorption is increased, and the activity is used routinely to monitor treatment responses in Gaucher's disease. We have lately shown widespread expression of the enzyme in murine tissues with particular reference to the skin, thymus, gut epithelia, and isolated dendritic cells, suggesting a possible role in immunity. To further clarify the significance of TRAP in human physiology, we have examined its distribution in non-skeletal human tissues and in CD34+ -derived human dendritic cells. TRAP mRNA determined by Northern blotting analysis was expressed abundantly in spleen, liver, colon, lung, small intestine, kidney, stomach, testis, placenta, lymph node, thymus, peripheral blood leukocyte, bone marrow, and fetal liver. Expression of TRAP protein was investigated by immunohistochemistry, with which the enzyme was identified in multiple tissues. Histochemical staining detected enzymatically active protein in spleen, lung, skin, colon, stomach, and ileum. Active TRAP was identified in CD34+ -derived immature dendritic cells and co-localized to intracellular CD63 positive organelles. When these cells were matured by induction with LPS, the TRAP activity increased fivefold and remained within the cell during the phase associated with CD63 surface expression. Our findings demonstrate widespread expression of TRAP in human tissues. Its abundant expression in epithelia and dendritic cells suggests a potential role in antigen processing and in immune responses.     

Annexin II binds to SHP2 and this interaction is regulated by HSP70 levels

The protein tyrosine phosphatase SHP2 is a positive effector of EGFR signaling. To improve our understanding of SHP2's function, we searched for additional binding proteins of SHP2. We found that Annexin II is an SHP2-binding protein. Physical interactions of SHP2 with Annexin II were confirmed in vivo. Furthermore, binding of SHP2 with Annexin II was regulated somewhat by EGF treatment and the extracellular Ca2+ chelator, EGTA. Previously, we reported that HSP70 levels can influence the binding of SHP2 with EGFR. Interestingly, increased HSP70 levels also inhibited the binding of SHP2 with Annexin II after EGF treatment in vivo. In addition, immunostaining experiments indicated that a fraction of SHP2 and Annexin II co-localized in the cell membrane region after EGF treatment. Our findings indicate that Annexin II is binding partner of SHP2 and the binding of SHP2 with Annexin II is affected by EGF stimulation, extracellular calcium levels, and the levels of HSP70.     

Glucose-6-phosphate dehydrogenase deficiency in northern Mexico and description of a novel mutation

Glucose-6-phosphate dehydrogenase deficiency (G6PD) is the most common enzyme pathology in humans; it is X-linked inherited and causes neonatal hyperbilirubinaemia, chronic nonspherocytic haemolytic anaemia and drug-induced acute haemolytic anaemia. G6PD deficiency has scarcely been studied in the northern region of Mexico, which is important because of the genetic heterogeneity described in Mexican population. Therefore, samples from the northern Mexico were biochemically screened for G6PD-deficiency, and PCR-RFLPs, and DNA sequencing used to identify mutations in positive samples. The frequency of G6PD deficiency in the population was 0.95% (n = 1993); the mutations in 86% of these samples were G6PD A^?202A/376G , G6PD A^?376G/968C and G6PD Santamaria^376G/542T . Contrary to previous reports, we demonstrated that G6PD deficiency distribution is relatively homogenous throughout the country (P = 0.48336), and the unique exception with high frequency of G6PD deficiency does not involve a coastal population (Chihuahua: 2.4%). Analysis of eight polymorphic sites showed only 10 haplotypes. In one individual we identified a new G6PD mutation named Mexico DF^193A>G (rs199474830), which probably results in a damaging functional effect, according to PolyPhen analysis. Proteomic impact of the mutation is also described.     

Structural basis of GC-1 selectivity for thyroid hormone receptor isoforms

Background

Multiple protein templates are commonly used in manual protein structure prediction. However, few automated algorithms of selecting and combining multiple templates are available.

Results

Here we develop an effective multi-template combination algorithm for protein comparative modeling. The algorithm selects templates according to the similarity significance of the alignments between template and target proteins. It combines the whole template-target alignments whose similarity significance score is close to that of the top template-target alignment within a threshold, whereas it only takes alignment fragments from a less similar template-target alignment that align with a sizable uncovered region of the target. We compare the algorithm with the traditional method of using a single top template on the 45 comparative modeling targets (i.e. easy template-based modeling targets) used in the seventh edition of Critical Assessment of Techniques for Protein Structure Prediction (CASP7). The multi-template combination algorithm improves the GDT-TS scores of predicted models by 6.8% on average. The statistical analysis shows that the improvement is significant (p-value < 10^-4). Compared with the ideal approach that always uses the best template, the multi-template approach yields only slightly better performance. During the CASP7 experiment, the preliminary implementation of the multi-template combination algorithm (FOLDpro) was ranked second among 67 servers in the category of high-accuracy structure prediction in terms of GDT-TS measure.

Conclusion

We have developed a novel multi-template algorithm to improve protein comparative modeling.     

Deciphering Serology to Understand the Ecology of Infectious Diseases in Wildlife

The ecology of infectious disease in wildlife has become a pivotal theme in animal and public health. Studies of infectious disease ecology rely on robust surveillance of pathogens in reservoir hosts, often based on serology, which is the detection of specific antibodies in the blood and is used to infer infection history. However, serological data can be inaccurate for inference to infection history for a variety of reasons. Two major aspects in any serological test can substantially impact results and interpretation of antibody prevalence data: cross-reactivity and cut-off thresholds used to discriminate positive and negative reactions. Given the ubiquitous use of serology as a tool for surveillance and epidemiological modeling of wildlife diseases, it is imperative to consider the strengths and limitations of serological test methodologies and interpretation of results, particularly when using data that may affect management and policy for the prevention and control of infectious diseases in wildlife. Greater consideration of population age structure and cohort representation, serological test suitability and standardized sample collection protocols can ensure that reliable data are obtained for downstream modeling applications to characterize, and evaluate interventions for, wildlife disease systems.     

Facultative response to a kleptoparasite by the cooperatively breeding pied babbler

In many cases of interspecific kleptoparasitism, hosts developdefensive behaviors to minimize the impact of kleptoparasites.Because vigilance and defensive behaviors are often costly,selection should favor hosts that adjust the amount of investmentneeded to minimize losses to kleptoparasitism. However, examplesof such facultative responses are rare. Here, we investigatethe response of cooperatively breeding pied babblers (Turdoidesbicolor) to the drongo (Dicrurus adsimilis), an avian kleptoparasitethat regularly follows pied babbler groups, often giving alarmcalls to alert the group to predators but also occasionallygiving false alarm calls in order to steal food items. We showthat pied babbler response to drongos varies markedly accordingto babbler group size. In small groups, where there are fewindividuals available to act as sentinels, babblers sentinelless when a drongo is present and respond strongly to drongoalarm calls. However, in large groups, where there are manyindividuals available to participate in predator vigilance,babblers sentinel more often when a drongo is present, rarelyrespond to drongo alarm calls, and aggressively displace drongos,with a consequent decline in the number of successful kleptoparasitismevents. This behavior represent a facultative response to akleptoparasite according to the costs versus benefits of toleratingtheir presence.