Effect of microalga-based diet on oxidative stress enzymes of African catfish,Clarias gariepinus

Here an indigenously isolated microalgal strain Ascochloris spp. cultivated in synthetic medium was evaluated as an aquaculture feed supplement. The daily dietary supplement includes microalgal feed (AF) and commercial diet feed (CF) (as control), respectively. These diets were fed separately to the juvenile Clarias gariepinus fishes (n = 4) under controlled conditions for an experimental period of 100 days. The protein, glycogen and lipid contents in the muscle extracts were found to be marginally higher in fishes that were fed with CF than AF diet. Similarly, CF fishes showed significantly higher glutathione-s-transferase, catalase, superoxide dismutase, and lipid peroxidase activities, except glutathione content. Zero mortality of the fishes with no significant difference in the overall body mass with the two dietary supplements strongly suggests that algal biomass could supplement the requisite nutrients for their metabolic activities. This preliminary investigation helps in exploring algal biomass as a potential alternative feed additive in the aquaculture industry.     

Surface charge characteristics of soil colloids of some different soil types

Most of the soil samples, on the basis of Δ pH measurements, were observed to carry net negative surface charges, except six samples, which carried net positive surface charges. In one case, the net surface charge was noticed to be zero. According to surface charge-pH curves, the colloid surfaces of soil samples of a Hapludalf and a Luvisol, were characterized as constant charge type. Their zero point of charge (zpc) was very low (near pH 3.0), and remained identical throughout the depth. The colloid surfaces of Tropudalf samples, especially those of B and C horizons, and net positively charged samples were characterized as constant potential type. In the former, the zpc increased from pH 3.45 (A horizon-D₃) to 6.35 (C horizon-D₁). Of all the samples studied, the highest zpc (pH 6.75) was recorded in one of the net positively charged samples (L₂₄). The electrochemical behaviour of constant potential type colloids was therefore similar to that exhibited by many metallic oxides. ΔG° values in Hapludalf and Luvisol colloids were near to H bonding (-5 to-10 kcal mol^?1), whereas in others the values were higher than that for H bonding, except for A horizons of Tropudalfs.     

Pre-treatment of Syndrex® protects mice from becoming diabetic after streptozotocin injection

Diabetes mellitus is a metabolic disorder characterized by hyperglycemia due to either insufficiency of insulin or inability of cells to respond to insulin. Many clinical and experimental evidence have suggested the strong association between hyperglycemia, oxidative stress and diabetic complications. Therefore, the antidiabetic drugs with antioxidant potential would have a higher therapeutic value. To check its antidiabetic and antioxidant properties in vivo, experiments were done wherein mice were fed with Syndrex^® in different schedules and/or made diabetic by intraperitoneal injection of streptozotocin. Animals fed with Syndrex^® prior to the induction of diabetes by streptozotocin injection showed resistance to an increase in blood glucose levels. This treatment increased the activities of antioxidant enzymes namely, catalase, glutathione reductase and superoxide dismutase and reduced serum triglyceride and cholesterol levels as compared to those found in uncontrolled diabetic mice. Among the three different schedules used for Syndrex^® treatment, the best effect was seen in the case of mice pretreated with Syndrex^® prior to STZ injection. In our opinion, Syndrex^® given along with insulin may reduce the amount of insulin dose required and because of its strong antioxidant activity would certainly help to reduce the development of diabetic complications.     

Isolation and characteristics of eight novel polymorphic microsatellite loci from the genome of garlic (Allium sativum L.)

Here we characterized eight novel polymorphic SSR markers, developed from an enriched genomic library of garlic (Allium sativum L.). These SSRs produced a total of 64 alleles across 90 garlic accessions, with an average of 8 alleles per locus. Values for observed (H_O) and expected (H_E) heterozygosity ranged from 0.16 to 0.77 (mean = 0.44) and from 0.22 to 0.86 (mean = 0.65), respectively. Six loci deviated significantly (P < 0.05) from Hardy–Weinberg equilibrium (HWE). The averages of gene diversity and PIC values were 0.65 and 0.62, respectively. The mean genetic similarity coefficient was 0.4380, indicating that among garlic accessions existed wide genetic variation. Based on 64 alleles obtained by 8 SSRs, a phenogram was constructed to understand the relationships among the 90 accessions. These newly developed SSRs should prove very useful tools for genotypes identification, assessment of genetic diversity and population structure in garlic.     

Insulin secretion from toadfish islet tissue stimulated by pyridine nucleotides

The addition of glucose stimulated release of insulin from the isolated islet tissue of the toadfish incubated in vitro. Reduced nicotinamide-adenine dinucleotide also stimulated insulin release, whereas the oxidized form had no effect. Both oxidized and reduced nicotinamide-adenine dinucleatide phosphate stimulated insulin release, but the reduced form was significantly more effective.     

ATM engages autodegradation of the E3 ubiquitin ligase COP1 after DNA damage

The ataxia telangiectasia mutated (ATM) protein kinase is a critical component of a DNA-damage response network configured to maintain genomic integrity. The abundance of an essential downstream effecter of this pathway, the tumor suppressor protein p53, is tightly regulated by controlled degradation through COP1 and other E3 ubiquitin ligases, such as MDM2 and Pirh2; however, the signal transduction pathway that regulates the COP1-p53 axis following DNA damage remains enigmatic. We observed that in response to DNA damage, ATM phosphorylated COP1 on Ser(387) and stimulated a rapid autodegradation mechanism. Ionizing radiation triggered an ATM-dependent movement of COP1 from the nucleus to the cytoplasm, and ATM-dependent phosphorylation of COP1 on Ser(387) was both necessary and sufficient to disrupt the COP1-p53 complex and subsequently to abrogate the ubiquitination and degradation of p53. Furthermore, phosphorylation of COP1 on Ser(387) was required to permit p53 to become stabilized and to exert its tumor suppressor properties in response to DNA damage.     

DUBA: a deubiquitinase that regulates type I interferon production

Production of type I interferon (IFN-I) is a critical host defense triggered by pattern-recognition receptors (PRRs) of the innate immune system. Deubiquitinating enzyme A (DUBA), an ovarian tumor domain-containing deubiquitinating enzyme, was discovered in a small interfering RNA-based screen as a regulator of IFN-I production. Reduction of DUBA augmented the PRR-induced IFN-I response, whereas ectopic expression of DUBA had the converse effect. DUBA bound tumor necrosis factor receptor-associated factor 3 (TRAF3), an adaptor protein essential for the IFN-I response. TRAF3 is an E3 ubiquitin ligase that preferentially assembled lysine-63-linked polyubiquitin chains. DUBA selectively cleaved the lysine-63-linked polyubiquitin chains on TRAF3, resulting in its dissociation from the downstream signaling complex containing TANK-binding kinase 1. A discrete ubiquitin interaction motif within DUBA was required for efficient deubiquitination of TRAF3 and optimal suppression of IFN-I. Our data identify DUBA as a negative regulator of innate immune responses.     

一氧化氮和繁殖控制

一氧化氮 (NO) ,被认为是动物体内重要的生物信使。NO是由 L -精氨酸在 NO合成酶的作用下合成的。NO合成酶在许多哺乳动物细胞中都有大量的同分异构体。近几年的研究结果表明 ,NO对繁殖功能的许多方面都有很大的影响。NO可控制下丘脑和垂体水平上的促性腺激素的分泌、LH峰的机制、性行为、性激素的合成、卵泡存活和排卵。本文对 NO控制下丘脑 -垂体 -性腺轴的关键分子机理进行综述     

Experimental Bubalian Fasciolosis: Kinetics of Antibody Response using 28 kDa Fasciola gigantica Cysteine Proteinase as Antigen

Tropical Animal Health and Production -