Conversion of xanthoxin to abscisic Acid by cell-free preparations from bean leaves

Cell-free extracts from the leaves of Phaseolus vulgaris L. convert xanthoxin to abscisic acid. The enzyme activity in dialyzed or acetone-precipitated extracts shows a strong dependence on either NAD or NADP. The enzyme activity appears to be cytosolic with no significant activity observed in chloroplasts. The activity was observed in extracts from roots of Phaseolus vulgaris, and also in extracts prepared from the leaves of Pisum sativum L., Zea mays L., Cucurbita maxima Duchesne, and Vigna radiata L. Neither water stress nor cycloheximide appear to significantly affect the level of enzyme activity in leaves. No intermediates between xanthoxin and abscisic acid were detected.     

Cellular systems for the study of the biosynthesis of polyamines and ethylene,as well as of virus multiplication

Leaves of Chinese cabbage from healthy plants or from those infected with turnip yellow mosaic virus yield protoplasts which convert methionine to protein, S-adenosylmethionine, decarboxylated S-adenosylmethionine, spermidine, spermine and 1-aminocyclopropane-1-carboxylate. The enzyme spermidine synthase is entirely cytosolic and has been purified extensively. An inhibitor of this enzyme, dicyclohexylamine, blocks spermidine synthesis in intact protoplasts, and in so doing stimulates spermine synthesis. Aminoethoxyvinylglycine blocks the conversion of S-adenosylmethionine to 1-aminocyclopropane-1-carboxylate, the precursor to ethylene, in protoplasts. This inhibitor markedly stimulates the synthesis of both spermidine and spermine. Essentially all the protoplasts obtained from new leaves of plants infected 7 days earlier are infected. On incubation, such protoplasts convert exogenous methionine to viral protein and viral spermidine whose specific radioactivity is twice that of total cell spermidine. Exogeneous spermidine is also converted to cell putrescine and viral spermidine and spermine. Normal and virus-infected cells are being studied for their content of phenolic acid amides of the polyamines.     

The human–primate interface in the New Normal: Challenges and opportunities for primatologists in the COVID-19 era and beyond

The emergence of SARS-CoV-2 in late 2019 and human responses to the resulting COVID-19 pandemic in early 2020 have rapidly changed many aspects of human behavior, including our interactions with wildlife. In this commentary, we identify challenges and opportunities at human–primate interfaces in light of COVID-19, focusing on examples from Asia, and make recommendations for researchers working with wild primates to reduce zoonosis risk and leverage research opportunities. First, we briefly review the evidence for zoonotic origins of SARS-CoV-2 and discuss risks of zoonosis at the human–primate interface. We then identify challenges that the pandemic has caused for primates, including reduced nutrition, increased intraspecific competition, and increased poaching risk, as well as challenges facing primatologists, including lost research opportunities. Subsequently, we highlight opportunities arising from pandemic-related lockdowns and public health messaging, including opportunities to reduce the intensity of problematic human–primate interfaces, opportunities to reduce the risk of zoonosis between humans and primates, opportunities to reduce legal and illegal trade in primates, new opportunities for research on human–primate interfaces, and opportunities for community education. Finally, we recommend specific actions that primatologists should take to reduce contact and aggression between humans and primates, to reduce demand for primates as pets, to reduce risks of zoonosis in the context of field research, and to improve understanding of human–primate interfaces. Reducing the risk of zoonosis and promoting the well-being of humans and primates at our interfaces will require substantial changes from “business as usual.” We encourage primatologists to help lead the way.     

Unwrapping the phase portrait features of adventitious crackle for auscultation and classification: a machine learning approach

Journal of Biological Physics - The paper delves into the plausibility of applying fractal, spectral, and nonlinear time series analyses for lung auscultation. The thirty-five sound signals of...     

The Light Skin Allele of SLC24A5 in South Asians and Europeans Shares Identity by Descent

Skin pigmentation is one of the most variable phenotypic traits in humans. A non-synonymous substitution (rs1426654) in the third exon of SLC24A5 accounts for lighter skin in Europeans but not in East Asians. A previous genome-wide association study carried out in a heterogeneous sample of UK immigrants of South Asian descent suggested that this gene also contributes significantly to skin pigmentation variation among South Asians. In the present study, we have quantitatively assessed skin pigmentation for a largely homogeneous cohort of 1228 individuals from the Southern region of the Indian subcontinent. Our data confirm significant association of rs1426654 SNP with skin pigmentation, explaining about 27% of total phenotypic variation in the cohort studied. Our extensive survey of the polymorphism in 1573 individuals from 54 ethnic populations across the Indian subcontinent reveals wide presence of the derived-A allele, although the frequencies vary substantially among populations. We also show that the geospatial pattern of this allele is complex, but most importantly, reflects strong influence of language, geography and demographic history of the populations. Sequencing 11.74 kb of SLC24A5 in 95 individuals worldwide reveals that the rs1426654-A alleles in South Asian and West Eurasian populations are monophyletic and occur on the background of a common haplotype that is characterized by low genetic diversity. We date the coalescence of the light skin associated allele at 22–28 KYA. Both our sequence and genome-wide genotype data confirm that this gene has been a target for positive selection among Europeans. However, the latter also shows additional evidence of selection in populations of the Middle East, Central Asia, Pakistan and North India but not in South India.     

Astrocyte-Specific Overexpression of Insulin-Like Growth Factor-1 Protects Hippocampal Neurons and Reduces Behavioral Deficits following Traumatic Brain Injury in Mice

Traumatic brain injury (TBI) survivors often suffer from long-lasting cognitive impairment that stems from hippocampal injury. Systemic administration of insulin-like growth factor-1 (IGF-1), a polypeptide growth factor known to play vital roles in neuronal survival, has been shown to attenuate posttraumatic cognitive and motor dysfunction. However, its neuroprotective effects in TBI have not been examined. To this end, moderate or severe contusion brain injury was induced in mice with conditional (postnatal) overexpression of IGF-1 using the controlled cortical impact (CCI) injury model. CCI brain injury produces robust reactive astrocytosis in regions of neuronal damage such as the hippocampus. We exploited this regional astrocytosis by linking expression of hIGF-1 to the astrocyte-specific glial fibrillary acidic protein (GFAP) promoter, effectively targeting IGF-1 delivery to vulnerable neurons. Following brain injury, IGF-1Tg mice exhibited a progressive increase in hippocampal IGF-1 levels which was coupled with enhanced hippocampal reactive astrocytosis and significantly greater GFAP levels relative to WT mice. IGF-1 overexpression stimulated Akt phosphorylation and reduced acute (1 and 3d) hippocampal neurodegeneration, culminating in greater neuron survival at 10d after CCI injury. Hippocampal neuroprotection achieved by IGF-1 overexpression was accompanied by improved motor and cognitive function in brain-injured mice. These data provide strong support for the therapeutic efficacy of increased brain levels of IGF-1 in the setting of TBI.     

Is MTHFR 677 C>T Polymorphism Clinically Important in Polycystic Ovarian Syndrome (PCOS)? A Case-Control Study,Meta-Analysis and Trial Sequential Analysis

Background

Optimum efficiency of the folate pathway is considered essential for adequate ovarian function. 677 C>T substitution in the 5, 10-methylene tertrahydrofolatereductase (MTHFR) gene compromises activity of the MTHFR enzyme by about 50%. The significance of correlation between 677C>T substitution and PCOS remains dubious due to the low power of published studies.

Methods and Results

We analyzed MTHFR 677 C>T site in ethnically two different PCOS case-control groups (total 261 cases and 256 controls) from India. The data analysis revealed a lack of association between this polymorphism and PCOS [OR = 1.11 (95%CI = 0.71–1.72), P = 0.66]. Group-wise analysis on the basis of ethnicity also revealed no association in any of the ethnic groups [Indo-Europeans, P = 1; Dravidians, P = 0.70]. Homocysteine levels did not differ significantly between cases (15.51 μmol/L, SD = 2.89) and controls (15.89 μmol/L, SD = 2.23). We also undertook a meta-analysis on 960 cases and 1028 controls, which suggested a significant association of the substitution with PCOS in the dominant model of analysis (OR = 1.47 (95%CI = 1.04–2.09), P = 0.032]. Trial sequential analysis corroborated findings of the traditional meta-analysis. However, we found that the conclusions of meta-analysis were strongly influenced by studies that deviated from the Hardy Weinberg equilibrium. A careful investigation of each study and a trial sequential analysis suggested that 677 C>T substitution holds no clinical significance in PCOS in most of the populations.

Conclusion

In conclusion, MTHFR 677 C>T polymorphism does not affect PCOS risk in India. The association seen in the meta-analysis is due to an outlier study and studies showing deviation from the Hardy Weinberg equilibrium.     

Aqueous Angiography: Real-Time and Physiologic Aqueous Humor Outflow Imaging

Purpose

Trabecular meshwork (TM) bypass surgeries attempt to enhance aqueous humor outflow (AHO) to lower intraocular pressure (IOP). While TM bypass results are promising, inconsistent success is seen. One hypothesis for this variability rests upon segmental (non-360 degrees uniform) AHO. We describe aqueous angiography as a real-time and physiologic AHO imaging technique in model eyes as a way to simulate live AHO imaging.

Methods

Pig (n = 46) and human (n = 6) enucleated eyes were obtained, orientated based upon inferior oblique insertion, and pre-perfused with balanced salt solution via a Lewicky AC maintainer through a 1mm side-port. Fluorescein (2.5%) was introduced intracamerally at 10 or 30 mm Hg. With an angiographer, infrared and fluorescent (486 nm) images were acquired. Image processing allowed for collection of pixel information based on intensity or location for statistical analyses. Concurrent OCT was performed, and fixable fluorescent dextrans were introduced into the eye for histological analysis of angiographically active areas.

Results

Aqueous angiography yielded high quality images with segmental patterns (p<0.0001; Kruskal-Wallis test). No single quadrant was consistently identified as the primary quadrant of angiographic signal (p = 0.06–0.86; Kruskal-Wallis test). Regions of high proximal signal did not necessarily correlate with regions of high distal signal. Angiographically positive but not negative areas demonstrated intrascleral lumens on OCT images. Aqueous angiography with fluorescent dextrans led to their trapping in AHO pathways.

Conclusions

Aqueous angiography is a real-time and physiologic AHO imaging technique in model eyes.     

Current advances and future directions in genetic enhancement of a climate resilient food legume crop,cowpea (Vigna unguiculata L. Walp.)

Plant Cell, Tissue and Organ Culture (PCTOC) - Cowpea (Vigna unguiculata (L.) Walp.) is a warm-season legume crop which is widely grown by resource-poor small and marginal farmers of Sub-Saharan...