Effect of chloral hydrate on metabolic rate of Labeo rohita (Ham) and Poecilia reticulata (Peters)

Comparative impact of chloral hydrate anaesthesia on the metabolic rate of Indian major carp Labeo rohita and larvivorous fish Poecilia reticulata was assessed. Observation on the Oxygen Consumption Rate (OCR) revealed that in common guppies OCR was substantially low (1.105 and 1.097 mg/g/hr) at 0.1 and 0.25 g/l concentrations of chloral hydrate as against OCR of 1.487 mg/g/hr in the control. Fry of L. rohita in group showed lower metabolic rates in the control as well as treated conditions as compared to the individuals of this fish. This may be due to sympathetic psychophysiological reflex of grouped fish. Higher dose of chloral hydrate (0.25 g/l) also caused higher OCR probably due to distress. Application of chloral hydrate also favoured lesser release of metabolic wastes (ammonia and carbon dioxide). There was significant positive correlation between time and oxygen consumption, whereas, for time and OCR this relationship was negative. Regression of chloral hydrate doses for OCR and time has also been calculated.

Winter Temperature and UV Are Tightly Linked to Genetic Changes in the p53 Tumor Suppressor Pathway in Eastern Asia

The tumor suppressor p53 is a master sensor of stress. Two human-specific polymorphisms, p53 codon 72 and MDM2 SNP309, influence the activities of p53. There is a tight association between cold winter temperature and p53 Arg72 and between low UV intensity

Prevalent positive epistasis in Escherichia coli and Saccharomyces cerevisiae metabolic networks

Epistasis refers to the interaction between genes. Although high-throughput epistasis data from model organisms are being generated and used to construct genetic networks(1-3), the extent to which genetic epistasis reflects biologically meaningful interactions remains unclear(4-6). We have addressed this question through in silico mapping of positive and negative epistatic interactions amongst biochemical reactions within the metabolic networks of Escherichia coli and Saccharomyces cerevisiae using flux balance analysis. We found that negative epistasis occurs mainly between nonessential reactions with overlapping functions, whereas positive epistasis usually involves essential reactions, is highly abundant and, unexpectedly, often occurs between reactions without overlapping functions. We offer mechanistic explanations of these findings and experimentally validate them for 61 S. cerevisiae gene pairs.

A de novo originated gene depresses budding yeast mating pathway and is repressed by the protein encoded by its antisense strand

Recent transcription profiling studies have revealed an unexpectedly large proportion of antisense transcripts in eukaryotic genomes. These antisense genes seem to regulate gene expression by interacting with sense genes. Previous studies have focused on the non-coding antisense genes, but the possible regulatory role of the antisense protein is poorly understood. In this study, we found that a protein encoded by the antisense gene ADF1 acts as a transcription suppressor, regulating the expression of sense gene MDF1 in Saccharomyces cerevisiae. Based on the evolutionary, genetic, cytological and biochemical evidence, we show that the protein-coding sense gene MDF1 most likely originated de novo from a previously non-coding sequence and can significantly suppress the mating efficiency of baker's yeast in rich medium by binding MAT alpha 2 and thus promote vegetative growth. These results shed new light on several important issues, including a new sense-antisense interaction mechanism, the de novo origination of a functional gene, and the regulation of yeast mating pathway.

Structure Elucidation and Theoretical Investigation of Key Steps in the Biogenetic Pathway of Schisanartane Nortriterpenoids by Using DFT Methods

Rubrifloradilactone C (4), a novel bioactive nortriterpenoid, along with four other nortriterpenoids (1-3, 5) were isolated from Schisandra rubriflora. The structure of 4 was determined by extensive NMR spectral analysis, computational evidence by using t

Metabolic changes in rat prefrontal cortex and hippocampus induced by chronic morphine treatment studied ex vivo by high resolution H-1 NMR spectroscopy

Ex vivo H-1 NMR spectroscopy was used to measure changes in the concentrations of cerebral metabolites in the prefrontal cortex (PFC) and hippocampus of rats subjected to repeated morphine treatment known to cause tolerance/dependence. The results show th

Acute behavioural stress facilitates long-term depression in temporoammonic-CAI pathway

Behavioural stress facilitates long-term depression in Schaffer collaterals-CAI pathway, but it is unknown whether it influences long-term depression in temporoammonic fibres-CAI. Here, we report that low-frequency stimulation induced long-term depression

Opiate withdrawal modifies synaptic plasticity in subicular-nucleus accumbens pathway in vivo

Subiculum receives output of hippocampal CAI neurons and projects glutamatergic synapses onto nucleus accumbens (NAc), the subicular-NAc pathway linking memory and reward system. It is unknown whether morphine withdrawal influences synaptic plasticity in

Fish-Specific Duplicated dmrt2b Contributes to a Divergent Function through Hedgehog Pathway and Maintains Left-Right Asymmetry Establishment Function

Gene duplication is thought to provide raw material for functional divergence and innovation. Fish-specific dmrt2b has been identified as a duplicated gene of the dmrt2a/terra in fish genomes, but its function has remained unclear. Here we reveal that Dmrt2b knockdown zebrafish embryos display a downward tail curvature and have U-shaped somites. Then, we demonstrate that Dmrt2b contributes to a divergent function in somitogenesis through Hedgehog pathway, because Dmrt2b knockdown reduces target gene expression of Hedgehog signaling, and also impairs slow muscle development and neural tube patterning through Hedgehog signaling. Moreover, the Dmrt2b morphants display defects in heart and visceral organ asymmetry, and, some lateral-plate mesoderm (LPM) markers expressed in left side are randomized. Together, these data indicate that fish-specific duplicated dmrt2b contributes to a divergent function in somitogenesis through Hedgehog pathway and maintains the common function for left-right asymmetry establishment.

Toll-like receptor 4 signaling pathway can be triggered by grass carp reovirus and Aeromonas hydrophila infection in rare minnow Gobiocypris rarus

Toll-like receptor 4 (TLR4) is critical for LPS recognition and cellular responses. It also recognizes some viral envelope proteins. Detection mostly results in the inflammation rather than specific antiviral responses. However, it's unclear in fish. In this report, a TLR4 gene (named as GrTLR4b) was cloned and characterized from rare minnow Gobiocypris rarus. The full length of GrTLR4b cDNA consists of 2766 nucleotides and encodes a polypeptide of 818 amino acids with an estimated molecular mass of 94,518 Da and a predicted isoelectric point of 8.41. The predicted amino acid sequence comprises a signal peptide, six leucine-rich repeat (LRR) motifs, one leucine-rich repeat C-terminal (LRRCT) motif, followed by a transmembrane segment of 23 amino acids, and a cytoplasmic region of 167 amino acids containing one Toll - interleukin 1 - receptor (TIR) motif. It's closely similar to the zebrafish (Danio rerio) TLR4b amino acid sequence with an identity of 77%. Quantitative RT-PCR analysis showed GrTLR4b mRNA was constitutive expression in gill, heart, intestine, kidney, liver, muscle and spleen tissues in healthy animals and up-regulated by viruses and bacteria. After being infected by grass carp reovirus or Aeromonas hydrophila, GrTLR4b expressions were up-regulated from 24 h post-injection and lasted until the fish became moribund (P < 0.05). These data implied that TLR4 signaling pathway could be activated by both viral and bacterial infection in rare minnow. (C) 2009 Elsevier Ltd. All rights reserved.