Markers/parameters for the evaluation of natural resistance status of small ruminants against gastrointestinal nematodes

The high prevalence of anthelmintic-resistant gastrointestinal nematodes (GINs) throughout the world has led to the need for alternative worm control strategies. One of the possible substitutes to reduce the problems of drug resistance and residue is the evaluation/breeding of small ruminants for greater resistance to the GINs (organically produced), which in turn would be a helpful tool to predict the performance of an animal. At present, the existing diversity in the genetic potential to resist/tolerate GINs infection both within and between breeds has been validated. Successful selection of animals to define the genotype and identified resistance is related to the employed markers. A number of phenotypic traits such as faecal egg count (FEC), worm burden, serum antibodies, peripheral eosinophilia, packed cell volume, live weight, serum protein and albumin concentrations have been used for this purpose both in natural and artificial infections. Relatively resistant/tolerant animals have also been found to have mastocytosis, globule leucocytes, high levels of histamine and immunoglobulin (Ig) A and IgE concentrations. Of these traits, the principal and most practical measurement used to assess resistance status in animals undergoing similar parasite challenges is FEC. FEC has a positive/negative correlation with other biochemical, cellular and immunological parameters; however, the reliability of individual trial is often questioned and valuable information regarding the genetic makeup can be obtained from pooled data of a large number of trials and parameters. This paper covers all the aspects reported in the literature on various parameters considered to evaluate the resistance status of a range of small ruminant breeds.     

Influence of varying sources of dietary electrolytes on the performance of broilers reared in a high temperature environment

Experiment using 297 broiler chicks, kept from 1 to 42 days under cyclic heat stress (minimum 29.3 °C and maximum 38 °C), was conducted to investigate the relative efficacies of three sodium (NaHCO₃, Na₂CO₃, Na₂SO₄), and potassium (KHCO₃, K₂CO₃, K₂SO₄) supplements at an identical dietary electrolyte balance (DEB) 250 mEq/kg and two chloride supplements (CaCl₂ and NH₄Cl) at DEB 50 mEq/kg. The desired levels of DEB were achieved by substitution of individual mineral supplement at the expense to builder's sand in the basal starter (DEB 185.6 mEq/kg) and finisher (DEB 174 mEq/kg) diet containing only salt as a source of Na and Cl. Each diet (one basal and eight experimental) was fed to three experimental units having 11 chicks each. The growth performances in K supplements, except KHCO₃, were poorer than those of Na supplements. The NaHCO₃, Na₂CO₃, Na₂SO₄ and NH₄Cl increased body weight gain, feed intake and improved feed to gain ratio than those of K₂CO₃ and K₂SO₄ after 42 days of age. These supplements also increased the water intake and resulted in lowered body temperature as well as reduced mortality. Very poor performance in CaCl₂ supplement was associated with disturbed calcium:phosphorus and very low blood pH (7.19). Better performance was noted with bicarbonate than that with carbonate and sulfate sources. The KHCO₃ accentuate the respiratory alkalosis by increasing blood HCO₃ contents (26.09 mmol/l) and gave poorer performance than NaHCO₃. Blood lymphocytes, hemoglobin, hematocrit and electrolyte balance in heat stressed broilers were better improved by NH₄Cl, NaHCO₃, Na₂CO₃, Na₂SO₄ and KHCO₃ than those of CaCl₂, K₂CO₃ and K₂SO₄ supplements. Present findings emphasized the importance of considering metabolisable anions supplemented in association with cations while balancing the dietary electrolyte equations. That is why DEB equation cannot be used to predict the relative benefits of different mineral supplements.     

Deficient glutathione in guard cells facilitates abscisic acid-induced stomatal closure but does not affect light-induced stomatal opening

We investigated the role of glutathione (GSH) in stomatal movements using a GSH deficient mutant, chlorinal-1 (ch1-1). Guard cells of ch1-1 mutants accumulated less GSH than wild types did. Light induced stomatal opening in ch1-1 and wild-type plants. Abscisic acid (ABA) induced stomatal closure in ch1-1 mutants more than wild types without enhanced reactive oxygen species (ROS) production. Therefore, GSH functioned downstream of ROS production in the ABA signaling cascade.     

Coinfection with <Emphasis Type="Italic">Lichtheimia corymbifera</Emphasis> and <Emphasis Type="Italic">Aspergillus flavus</Emphasis> in an Immune-Competent Patient Mimicking as Pulmonary-Renal Syndrome

Lichtheimia corymbifera and Aspergillus flavus pulmonary coinfection has been rarely reported in immune-competent patients. We report case of a young male who presented with clinical features of pulmonary-renal syndrome and was later diagnosed to have bilateral polymicrobial fungal lung infection.     

Cloning and heterologous expression of a novel subgroup of class IV polyhydroxyalkanoate synthase genes from the genus Bacillus

Many microorganisms harbor genes necessary to synthesize biodegradable plastics known as polyhydroxyalkanoates (PHAs). We surveyed a genomic database and discovered a new cluster of class IV PHA synthase genes (phaRC). These genes are different in sequence and operon structure from any previously reported PHA synthase. The newly discovered PhaRC synthase was demonstrated to produce PHAs in recombinant Escherichia coli.     

The chemical cell biology of zinc: structure and intracellular fluorescence of a zinc-quinolinesulfonamide complex

p -toluenesulfonamido-quinoline, TSQ, are potentially powerful probes of intracellular zinc chemistry; however, the structure, thermodynamics, and stoichiometry of the metal complexes, and the molecular basis of Zn(II) recognition, remain open issues. To address these, we report the first structural characterization of a Zn(II) complex of a TSQ derivative, namely 2-methyl-6-methoxy-8-p-toluenesulfonamido-quinoline (3) and describe its unusual coordination chemistry. The crystal structure of the fluorescent complex of 3 with zinc reveals a 2 : 1 stoichiometry wherein bidentate coordination of two nitrogens from each ligand gives rise to a highly distorted tetrahedral Zn(II) center. Both sulfonamido groups in the zinc complex are tilted away from zinc to make room for coordination of the amide nitrogens. Zn-O(2) and Zn-O(4) distances are essentially nonbonding (3.06 and 3.10 Å, respectively). The bond angles [N(1)-Zn-N(2) 83.5° and N(3)-Zn-N(4) 83.0°] are quite small relative to the 109° angle of an ideal tetrahedral center. This result provides an insight into the zinc-binding mode of the TSQ derivative zinquin, in which a methyl group replaces the hydrogen in the 2-position of the quinoline ring. The methyl group and sulfonamide oxygen atoms clearly hinder formation of both square planar and octahedral complexes. We also show here that the Zn(II) complex of 3 in DMSO-water (80/20 w/w) exhibits an overall binding stability (logβ ₂ = 18.24 ± 0.02) similar to zinquin. Fluorescence microscopy suggests that each of these members of this family demarks a similar set of Zn(II)-enriched compartments that are common to all eukaryotic cells examined to date, and further shows that the ester function is not required for observation of these ubiquitous Zn-loaded compartments. The combined structural, thermodynamic, and physiological results provide a basis for design of other Zn(II)-specific membrane permeant probes with a range of Zn(II) affinities and photophysical properties. Received: 8 May 1999 / Accepted: 15 September 1999     

Estimation of Genetic Divergence and Character Association Studies in Local and Exotic Diversity Panels of Soybean (<i>Glycine max</i> L.) Genotypes

The availability of favorable genetic diversity is a thriving vitality for the success of a breeding program. It provides a firm basis of selecting superior breeding lines for the development of high yielding crop genotypes. In this context, present investigation aimed to generate information on genetic divergence and character association in a diversity panel of 123 local and exotic soybean genotypes. Analysis of variance revealed significant response of the evaluated genotypes based on studied attributes. It depicted the probability of selecting desirable soybean genotypes by focusing on character association studies and genetic diversity analysis. Correlation analysis revealed that seed yield per plant showed high positive correlation with 100-seed weight followed by pods per plant and plant height. Furthermore, path coefficient analysis exposed that pods per plant had maximum direct contribution in seed yield per plant followed by 100-seed weight, days to flowering and SPAD measurement. Genotype named “G-10” showed maximum yield per plant followed by 24607, G-52, 24593, Arisoy, 24566, 17426, A-3127, 24570 and 24567. Genetic diversity analysis grouped the evaluated germplasm into 17 clusters. All clusters showed zero intra-cluster variability; while inter-cluster divergence ranged from 9.00 to 91.11. Cluster V showed maximum inter-cluster distance with cluster XII followed by that of between V and VIII. Moreover, cluster IV with superior genotypes (G-10, 24607, 24593 and 24566), VI (17426 and 24567), XIII (24570) and X (Arisoy and G-52) showed above mean values for most of the studied characters. Overall, the results of hybridization between the superior genotypes of these cluster pairs might be useful for soybean breeding with improving agronomic traits and adaptability.     

Determination of bacterially derived auxins using a microplate method

Rapid and efficient methods for determining the ability of soil and rhizosphere bacteria to produce key metabolites which are useful in growth promotion or suppression of plant growth are needed. A microplate method was developed and compared to a standard method for assays of auxin compounds produced by bacteria. The microplate method was similar to the standard method in accuracy of determination, required less chemical reagents, and considerably reduced the time required for analyses.