Elevational gradients of reptile richness in the southern Western Ghats of India: Evaluating spatial and bioclimatic drivers

Exploring elevational patterns in species richness and their underlying mechanisms is a major goal in biogeography and community ecology. Reptiles can be powerful model organisms to examine biogeographical patterns. In this study, we examine the elevational patterns of reptile species richness and test a series of hypotheses that may explain them. We sampled reptile communities along a tropical elevational gradient (100–1,500 m a.s.l.) in the Western Ghats of India using time‐constrained visual encounter surveys at each 100‐m elevation zone for 3 years. First, we investigated species richness patterns across elevation and the support of mid‐domain effect and Rapoport's rule. Second, we tested whether a series of bioclimatic (temperature and tree density) and spatial (mid‐domain effect and area) hypotheses explained species richness. We used linear regression and AICc to compare competing models for all reptiles, and each of the subgroups: snakes, lizards, and Western Ghats’ endemics. Overall reptile richness and lizard richness both displayed linear declines with elevation, which was best explained by temperature. Snake richness and endemic species richness did not systematically vary across elevation, and none of the potential hypotheses explained variation in them. This is the first standardized sampling of reptiles along an elevational gradient in the Western Ghats, and our results agree with the global view that temperature is the primary driver of ectotherm species richness. By establishing strong reptile diversity–temperature associations across elevation, our study also has implications for the impact of future climate change on range‐restricted species in the Western Ghats.     

Evaluation of an Online Platform for Multiple Sclerosis Research: Patient Description,Validation of Severity Scale,and Exploration of BMI Effects on Disease Course

Objectives

To assess the potential of an online platform, PatientsLikeMe.com (PLM), for research in multiple sclerosis (MS). An investigation of the role of body mass index (BMI) on MS disease course was conducted to illustrate the utility of the platform.

Methods

First, we compared the demographic characteristics of subjects from PLM and from a regional MS center. Second, we validated PLM’s patient-reported outcome measure (MS Rating Scale, MSRS) against standard physician-rated tools. Finally, we analyzed the relation of BMI to the MSRS measure.

Results

Compared with 4,039 MS Center patients, the 10,255 PLM members were younger, more educated, and less often male and white. Disease course was more often relapsing remitting, with younger symptom onset and shorter disease duration. Differences were significant because of large sample sizes but small in absolute terms. MSRS scores for 121 MS Center patients revealed acceptable agreement between patient-derived and physician-derived composite scores (weighted kappa = 0.46). The Walking domain showed the highest weighted kappa (0.73) and correlation (rs = 0.86) between patient and physician scores. Additionally, there were good correlations between the patient-reported MSRS composite and walking scores and physician-derived measures: Expanded Disability Status Scale (composite rs = 0.61, walking rs = 0.74), Timed 25 Foot Walk (composite rs = 0.70, walking rs = 0.69), and Ambulation Index (composite rs = 0.81, walking rs = 0.84). Finally, using PLM data, we found a modest correlation between BMI and cross-sectional MSRS (rho = 0.17) and no association between BMI and disease course.

Conclusions

The PLM population is comparable to a clinic population, and its patient-reported MSRS is correlated with existing clinical instruments. Thus, this online platform may provide a venue for MS investigations with unique strengths (frequent data collection, large sample sizes). To illustrate its applicability, we assessed the role of BMI in MS disease course but did not find a clinically meaningful role for BMI in this setting.     

The first genetic map of the American cranberry: exploration of synteny conservation and quantitative trait loci

The first genetic map of cranberry (Vaccinium macrocarpon) has been constructed, comprising 14 linkage groups totaling 879.9 cM with an estimated coverage of 82.2 %. This map, based on four mapping populations segregating for field fruit-rot resistance, contains 136 distinct loci. Mapped markers include blueberry-derived simple sequence repeat (SSR) and cranberry-derived sequence-characterized amplified region markers previously used for fingerprinting cranberry cultivars. In addition, SSR markers were developed near cranberry sequences resembling genes involved in flavonoid biosynthesis or defense against necrotrophic pathogens, or conserved orthologous set (COS) sequences. The cranberry SSRs were developed from next-generation cranberry genomic sequence assemblies; thus, the positions of these SSRs on the genomic map provide information about the genomic location of the sequence scaffold from which they were derived. The use of SSR markers near COS and other functional sequences, plus 33 SSR markers from blueberry, facilitates comparisons of this map with maps of other plant species. Regions of the cranberry map were identified that showed conservation of synteny with Vitis vinifera and Arabidopsis thaliana. Positioned on this map are quantitative trait loci (QTL) for field fruit-rot resistance (FFRR), fruit weight, titratable acidity, and sound fruit yield (SFY). The SFY QTL is adjacent to one of the fruit weight QTL and may reflect pleiotropy. Two of the FFRR QTL are in regions of conserved synteny with grape and span defense gene markers, and the third FFRR QTL spans a flavonoid biosynthetic gene.     

Raman Spectroscopic Study of Radioresistant Oral Cancer Sublines Established by Fractionated Ionizing Radiation

Radiotherapy is an important treatment modality for oral cancer. However, development of radioresistance is a major hurdle in the efficacy of radiotherapy in oral cancer patients. Identifying predictors of radioresistance is a challenging task and has met with little success. The aim of the present study was to explore the differential spectral profiles of the established radioresistant sublines and parental oral cancer cell lines by Raman spectroscopy. We have established radioresistant sublines namely, 50Gy-UPCI:SCC029B and 70Gy-UPCI:SCC029B from its parental UPCI:SCC029B cell line, by using clinically admissible 2Gy fractionated ionizing radiation (FIR). The developed radioresistant character was validated by clonogenic cell survival assay and known radioresistance-related protein markers like Mcl-1, Bcl-2, Cox-2 and Survivin. Altered cellular morphology with significant increase (p<0.001) in the number of filopodia in radioresistant cells with respect to parental cells was observed. The Raman spectra of parental UPCI:SCC029B, 50Gy-UPCI:SCC029B and 70Gy-UPCI:SCC029B cells were acquired and spectral features indicate possible differences in biomolecules like proteins, lipids and nucleic acids. Principal component analysis (PCA) provided three clusters corresponding to radioresistant 50Gy, 70Gy-UPCI:SCC029B sublines and parental UPCI:SCC029B cell line with minor overlap, which suggest altered molecular profile acquired by the radioresistant cells due to multiple doses of irradiation. The findings of this study support the potential of Raman spectroscopy in prediction of radioresistance and possibly contribute to better prognosis of oral cancer.     

Horizontal and vertical movement of Pseudomonas fluorescens toward exudate of Macrophomina phaseolina in soil: influence of motility and soil properties

The role of motility and cell surface hydrophobicity in transport and dispersal of Pseudomonas fluorescens strains LAM1-hydrophilic, LAM2-hydrophobic and LAM(NM) (non-motile mutant of LAM2) under different soil conditions was studied. Maximum adhesion was recorded for LAM2 in clay loam (70%), followed by sandy loam (68%) and sandy soil (40%). Vertical migration of P fluorescens isolates in soils was recorded at 5 and 25 cm flow of wafer or M. phaseolina exudate. In all the treatments, LAM1 exhibited maximum migration followed, by LAM2 and LAM(NM). The rate of migration of such isolates was lowered in water irrigated soils compared to those irrigated with M. phaseolina exudate. In sandy soil, cells of LAM1 migrated up to 13 cm in comparison to LAM2 (11 cm) and LAN(NM) (9 cm) at 5 cm flow of fungal exudate. Population of LAM1, LAM2 and LAM(NM) was 5.7, 5.68 and 5.61 log cfu g(-1) soil at 1 cm depth, but it decreased to 2.56, 2.21 and 1.99 log cfu during migration up to 11 cm in sandy soil at 5 cm flow of fungal exudate. Greater motility was observed in sandy soil irrigated with water or fungal exudate, followed by sandy loam and clay loam. In general, filtration coefficient (lambda) of P. fluorescens was higher in soils irrigated with 5 cm of water or exudate than with 25 cm of irrigation. The horizontal movement of P. fluorescens strains in sandy soil adjusted at different psi m showed marked reduction with decrease in psi m. The non-motile LAN(NM) did not show chemotactic response and migrated up to a maximum of 3 mm in saturated soils (0 kPa). After 96 h, LAM1 and LAM2 migrated upto 35 and 29 mm respectively in sandy soil. Motile isolates had significantly greater colonization of M. phaseolina sclerotia over the non-motile mutant.     

Scale-dependent selection of greenness by African elephants in the Kruger-private reserve transboundary region,South Africa

Foraging behaviour and habitat selection occur as hierarchical processes. Understanding the factors that govern foraging and habitat selection thus requires investigation of those processes over the scales at which they occur. We investigated patterns of habitat use by African elephants (Loxodonta africana) in relation to vegetation greenness to investigate the scale at which that landscape attribute was most closely related to distribution of elephant locations. We analysed Global Positioning System radio-collar locations for 15 individuals, using the Normalized Difference Vegetation Index as a representation of vegetation greenness in a Geographic Information Systems framework. We compared the importance of vegetation greenness at three spatial scales: the total home range, the seasonal home range and the 16-day home range. During the wet season, seasonal home ranges for both sexes were associated with intermediate greenness within the total home range; there was no evidence of selection based on greenness at finer scales. During the dry season, the strongest associations were within the 16-day home range: individual locations for males tended to be in areas of intermediate greenness, and those for females were in areas of intermediate and high greenness. Our findings suggest that the role of vegetation greenness varies with the scale of analysis, likely reflecting the hierarchical processes involved in habitat selection by elephants.     

Molecular cloning, sequence analysis and structure modeling of OmpR, the response regulator of Aeromonas hydrophila

The ability of bacteria to survive and proliferate in changing environmental conditions, and during host cell invasion is the key to their pathogenicity. In order to achieve this, the bacteria use a signal transduction system, the two component regulatory system, which consists of a sensor kinase and a response regulator. The EnvZ/OmpR system regulates the porin genes ompF/ompC in response to changes in osmolarity. In the present study, the ompR gene of Aeromonas hydrophila (isolate Ah17) was cloned, sequenced and characterized. Further an attempt was made to analyze the structural characteristics of the OmpR protein from Aeromonas hydrophila. The three dimensional structure of the protein was predicted by homology modeling and the modeled structure was compared to other members of two component response regulators. This study would be helpful for structure based drug design approaches to generate drugs against this harmful pathogen to control its proliferation in both human and fish hosts.     

A novel lectin (morniga M) from mulberry (<Emphasis Type="Italic">Morus nigra</Emphasis>) bark recognizes oligomannosyl residues in N-Glycans

Morniga M is a jacalin-related and mannose-specific lectin isolated from the bark of the mulberry (Morus nigra). In order to understand the function and application of this novel lectin, the binding property of Morniga M was studied in detail using an enzyme-linked lectinosorbent assay and lectin-glycan inhibition assay with extended glycan/ligand collection. From the results, it was found that the di-, tri-, and oligomannosyl structural units of N-glycans such as those of the bovine ₁-acid glycoprotein (gp) and lactoferrin were the most active gps, but not the O-glycans or polysaccharides including mannan from yeast. The binding affinity of Morniga M for ligands can be ranked in decreasing order as follows: gps carrying multiple N-glycans with oligomannosyl residues >> N-glycopeptide with a single trimannosyl core > Tri-Man oligomer [Man1 6(Man 1 3) Man], Penta-Man oligomer [Man1 6(Man1 3)Man1 6(Man1 3) Man] Man 1 2, 3 or 6 Man > Man > GlcNAc, Glc >> L-Fuc, Gal, GalNAc (inactive), demonstrating the unique specificity of this lectin that may not only assist in our understanding of cell surface carbohydrate ligand-lectin recognition, but also provide informative guidelines for the application of this structural probe in biotechnological and clinical regimens, especially in the detection and purification of N-linked glycans.