Synonymous codon usage in chloroplast genome of Coffea arabica

Synonymous codon usage of 53 protein coding genes in chloroplast genome of Coffea arabica was analyzed for the first time to find out the possible factors contributing codon bias. All preferred synonymous codons were found to use A/T ending codons as chloroplast genomes are rich in AT. No difference in preference for preferred codons was observed in any of the two strands, viz., leading and lagging strands. Complex correlations between total base compositions (A, T, G, C, GC) and silent base contents (A₃, T₃, G₃, C₃, GC₃) revealed that compositional constraints played crucial role in shaping the codon usage pattern of C. arabica chloroplast genome. ENC Vs GC₃ plot grouped majority of the analyzed genes on or just below the left side of the expected GC₃ curve indicating the influence of base compositional constraints in regulating codon usage. But some of the genes lie distantly below the continuous curve confirmed the influence of some other factors on the codon usage across those genes. Influence of compositional constraints was further confirmed by correspondence analysis as axis 1 and 3 had significant correlations with silent base contents. Correlation of ENC with axis 1, 4 and CAI with 1, 2 prognosticated the minor influence of selection in nature but exact separation of highly and lowly expressed genes could not be seen. From the present study, we concluded that mutational pressure combined with weak selection influenced the pattern of synonymous codon usage across the genes in the chloroplast genomes of C. arabica.     

Erratum to: Neuroprotective Effect of Hesperidin on Aluminium Chloride Induced Alzheimer’s Disease in Wistar Rats

Neurochemical Research -     

Correction to: Dietary Supplementation of Walnut Partially Reverses 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine Induced Neurodegeneration in a Mouse Model of Parkinson’s Disease

Neurochemical Research - The original version of this article unfortunately contains an error in Fig. 2a (4th image for walnut). This has been corrected by publishing this erratum.     

Constant light influences the circadian oscillations of circulatory lipid peroxidation, antioxidants and some biochemical variables in rats

Temporal oscillations of circulatory thiobarbituric acid reactive substances (TBARS), antioxidants such as reduced glutathione (GSH), superoxide dismutase (SOD), and catalase and glucose, cholesterol, total protein and aspartate transaminase (AST) were studied under LD (12:12 h) and constant light (LL) (500 lux) conditions after exposing the animal for 21 days. Advances in the acrophase of GSH, SOD, catalase, glucose, total protein and (AST) rhythms and delays in TBARS and cholesterol were found; amplitude and mesor values of these rhythms were found to be altered during constant light treatment. The above said circadian alterations during LL exposure may be due to (1) formation of photooxidants and stress mediated lipid peroxidation, suppression of melatonin (2) modulation of neuroendocrine and neurotransmitters rhythm (3) suppression of sleep - wake cycle (4) feeding and locomotion rhythm. The exact mechanism still remains to be explored and further research needed.     

Cloning and sequencing of partial DNA-A of Cassava mosaic virus

Abstract

Polymerase chain reaction of Cassava mosaic virus revealed that out of the 50 samples analysed only two samples, one from Musiri (Trichy district) and other from Mallur (Salem district), were detected with ICMV infection as 904 bp fragment of DNA-A amplified. All the other samples from various districts of Tamil Nadu were detected invariably with SLCMV as they amplified 599 bp of DNA-A. A 599 bp fragment of DAN-A was cloned and sequenced from the sample collected from Mallur. The nucleotide sequence has been submitted to GenBank under the accession number DQ303479. The nucleotide sequence was compared with other cassava infecting geminiviruses and other geminiviruses in GenBank. Cluster dendrogram revealed that the cloned sequence was most closely related to ICMV, Maharastra strain rather than SLCMV, forming one cluster. Comparative sequence analyses showed that the cloned fragment shared a maximum sequence identity with ICMV at nucleotide levels (93%) than with SLCMV (88%).     

Turbinaria conoides (J. Agardh) sulfated polysaccharide protects rat's heart against myocardial injury

In recent years, sulfated polysaccharide (fucoidan) is being marketed as a nutraceutical and food supplement because of its various established pharmacological activities. Hence this study was designed to investigate the protective effect of fucoidan extracted from Turbinaria conoides against isoproterenol induced myocardial injured rats. Biochemical assessment of myocardial injury was done by measuring the activities of creatine kinase, lactate dehydrogenase, membrane bound triphosphatases and minerals, which were significantly altered in isoproterenol administered rats. In addition, the enzyme mapping assay on the size of myocardial infarct also correlated with these biochemical parameters. Thus, the observed protective effects of sulfated polysaccharides of T. conoides against ISO induced myocardial injury are due to membrane stabilizing property and this property might be due to decreased lipid peroxidation. These results may trigger a renewed interest in the use of T. conoides fucoidan for myocardial injury.     

Influence of monosodium glutamate on circadian rhythms of lipid peroxidation products and antioxidants in rats

Monosodium glutamate (MSG) was administrated subcutaneously for 60 days to Wistar rats and 24h rhythms of thiobarbituric acid reactive substances (TBARS) and antioxidants such as reduced glutathione, superoxide dismutase and catalase were studied. MSG treatment was found to advance TBARS and to delay the acrophases of GSH and catalase. Amplitude and mesor values of these rhythms were found to be altered during MSG treatment. As glutamate levels in brain were found to be significantly increased (in MSG), we hypothesize that increased glutamate levels in brain could alter these biochemical rhythms probaly by modulating the transmission in several areas/nuclei in brain.     

Influences of Chronic Mild Stress Exposure on Motor,Non-Motor Impairments and Neurochemical Variables in Specific Brain Areas of MPTP/Probenecid Induced Neurotoxicity in Mice

Parkinson''s disease (PD) is regarded as a movement disorder mainly affecting the elderly population and occurs due to progressive loss of dopaminergic (DAergic) neurons in nigrostriatal pathway. Patients suffer from non-motor symptoms (NMS) such as depression, anxiety, fatigue and sleep disorders, which are not well focussed in PD research. Depression in PD is a predominant /complex symptom and its pathology lies exterior to the nigrostriatal system. The main aim of this study is to explore the causative or progressive effect of chronic mild stress (CMS), a paradigm developed as an animal model of depression in1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (25 mg/kg. body wt.) with probenecid (250 mg/kg, s.c.) (MPTP/p) induced mice model of PD. After ten i.p. injections (once in 3.5 days for 5 weeks) of MPTP/p or exposure to CMS for 4 weeks, the behavioural (motor and non-motor) impairments, levels and expressions of dopamine (DA), serotonin (5-HT), DAergic markers such as tyrosine hydroxylase (TH), dopamine transporter (DAT), vesicular monoamine transporters—2 (VMAT 2) and α-synuclein in nigrostriatal (striatum (ST) and substantia nigra (SN)) and extra-nigrostriatal (hippocampus, cortex and cerebellum) tissues were analysed. Significantly decreased DA and 5-HT levels, TH, DAT and VMAT 2 expressions and increased motor deficits, anhedonia-like behaviour and α-synuclein expression were found in MPTP/p treated mice. Pre and/or post exposure of CMS to MPTP/p mice further enhanced the MPTP/p induced DA and 5-HT depletion, behaviour abnormalities and protein expressions. Our results could strongly confirm that the exposure of stress after MPTP/p injections worsens the symptoms and neurochemicals status of PD.