The function and structural influence of selective relaxed constraint at functional intracellular loop3 of 5-HT1A serotonin-1 receptor family

Serotonin (5-HT) and its receptors have been involved in critical signal transduction mechanism and deregulation implicated in mood-related disorders. 5-HT activities are mediated through a family of transmembrane spanning serotonin receptors. Both within the family and species, 5-HT receptor protein sequence diversity and 7-transmembrane structural homogeneity have long been intriguing. In this study, we have analyzed the codon site constraint in 5-HT1 subclass receptors from 13 orthologous mammalian mRNA coding sequence. Further, the study was extended to computationally investigate the impact of non-synonymous sites with respect to function and structural significance through sequence homology algorithm and molecular dynamics simulation (MDS). Codon sites with significant posterior probability were observed in 5-HT_1A, 5‐HT_1B and 5-HT_1D receptor indicating variations in site constraint within the 5‐HT1 sub-class genes. In 5-HT_1A receptor, seven sites were detected at the functional intracellular loop₃ (ICL₃) with higher substitution rate through Codeml program. Sequence homology algorithm identifies that these sites were functionally tolerant within the mammals representing a selectively relaxed constraint at this domain. On the other hand, the root mean square deviation (rmsd) values from MDS suggest differences in structural conformation of ICL₃ models among the species. Specifically, the human ICL₃ model fluctuation was comparatively more stable than other species. Hence, we argue that these sites may have varying influence in G-proteins coupling and activation of effectors systems through downstream interacting accessory proteins of cell among the species. However, further experimental studies are required to elucidate the precise role and the seeming difference of these sites in 5-HT receptors between species.     

Competitive cellular uptake of nanoparticles made from polystyrene, poly(methyl methacrylate), and polylactide

The uptake behavior of negatively charged fluorescent nanoparticles made from different polymers (PS, PMMA, and PLLA) is studied on HeLa cells. All particles are obtained by the miniemulsion process using sodium dodecylsulfate as anionic surfactant. The size of the particles is in the range 105-125 nm. Cell uptake is analyzed by flow cytometry and reveals a higher uptake of PLLA particles compared to PMMA and PS particles. In competitive uptake studies two different types of particles are co-incubated with the HeLa cells; the results indicate a mutual influence of the particles on their uptake behavior. A reduced internalization of PLLA particles in the presence of PS particles is observed, although neither the co-incubation of PMMA and PLLA nor of PMMA and PS shows similar effect.     

Determination of the structure of lipid vesicle-bound angiotensin II and angiotensin I

A mass spectrometry (MS)-based strategy was developed to determine the structure of lipid vesicle-bound angiotensin II (AII) and angiotensin I (AI). It involves hydrogen-deuterium exchange (HDX), chemical modifications (e.g., nitration of tyrosine, acetylation of free amino group), and ladder sequencing. HDX is also combined with tandem mass spectrometry (MS/MS) to provide structural details at individual amino acid residues. It was observed that a major portion of both of these peptide hormones interacts with the phospholipid head groups on the surface of the vesicles and that Tyr residue is embedded in the vesicles. Both peptides have a U-shaped structure in the lipid environment.     

Effect of Different Levels of Selenium Supplementation on Growth Rate,Nutrient Utilization,Blood Metabolic Profile,and Immune Response in Lambs

The nutritional role of silver for the freshwater crustacean, Daphnia magna, was examined through four generations of deprivation. Silver inclusion in animal media was set at a nominal zero (employing chemicals of the highest available purity). Both reproduction (−60%) and life span (−40%) were negatively affected when compared to animals reared in the presence of 0.4 ng g⁻¹ Ag. These results strongly suggest a nutritional requirement of silver for daphnids at nanomolar concentrations.     

两种草蛉对取食棉花的扶桑绵粉蚧的嗅觉反应（英文）

捕食性的普通草蛉Chrysoperla sp.（carnea group） 和安平草蛉Mallada desjardinsi（Navas）（脉翅目:草蛉科）的寄主-生境定位取决于其觅食行为以及对各阶段释放的植物气味的行为反应.本研究调查了这两种交配的草蛉成虫以及取食棉花的扶桑绵粉蚧Phenacoccus solenopsis的反应,以便了解它们之间的三重营养关系.结果表明：草蛉雄虫和雌虫均能感受到棉花植株释放的绿叶挥发物;植株的各个阶段均可使捕食性昆虫和绵粉蚧定位.在受绵粉蚧为害的棉叶上饱和烃含量高,说明草蛉成虫的反应更为强烈;在植株受为害期和开花期释放捕食性昆虫,可提高田间捕食性昆虫的作用.这些结果提示有效的生物防治取决于捕食性昆虫在植株上的天然定殖能力以及对害虫的吞食能力.     

Role of Nosema bombycis infected male silk moths in the venereal transmission of pebrine disease in Bombyx mori (Lep., Bombycidae)

Abstract: The role of male moths of silkworm in the spread of pebrine spores (disease) has been studied using appropriate crossings and examining the multiplication of spores in the testis. Sections of infected testis reveal the presence of spores in the peritoneal sheath, spermatids but not in the sperm. A large number of spores was observed in the bursa copulatrix of the uninfected female moth mated with an infected male moth. This is a first record of venereal transmission of pebrine spores in silkworms. Venereally transmitted spores do not contribute to transovarial transmission, but give a false positive indication during mother-moth examination. An alternative method for mother-moth testing has also been discussed.     

A STRUCTURAL STUDY OF RAT LIVER RIBOSOMES

Polyribosomes, ribosomes, and ribosomal subunits were prepared from rat liver using sodium deoxycholate and a variety of ionic media. They were examined in the electron microscope, mainly as negatively or positively stained preparations, and in the analytical ultracentrifuge. The polyribosomes consist of up to twelve or more ribosomes linked by a fine strand, 10 to 15 A in diameter, probably of RNA. The ribosomes are approximately spherical with diameters of 250 to 300 A, and are estimated to be about 50 per cent porous. Possibly because of their high protein content, whole ribosomes show no cleavage furrows. Ribosomes were dissociated in phosphate buffer and the subunits separated on sucrose density gradients containing 10 per cent formalin. Three classes of subunit were obtained with sedimentation coefficients of 71S, 50S, and 31S respectively. The smallest, 31S subunit is about 250 A long by 100 A wide. The largest subunits appear to be clusters of smaller particles. It is estimated from their linear dimensions in electron micrographs that the whole 83S ribosome could contain up to six 31S subunits, or their equivalent.     

PCR-based assay for the rapid detection of fumonisin-producing Fusarium species in maize-based animal and poultry feeds in Karnataka,India

Abstract

One hundred and fourteen animal feedstuffs and eighty poultry feed mixtures commonly used for animal and poultry nutrition in Karnataka, India, were analysed for Fusarium contamination. The total counts of fusaria in animal feeds and poultry feed mixtures revealed a high incidence of F. verticillioides, being isolated from all positive samples. Most contaminated samples were maize pellets (71.4%), cotton seed (66.6%), maize powder (60%) and fine wheat bran (50%), respectively, while no Fusarium species was isolated from Bengal gram husk and wheat flakes. All the Fusarium species were identified by the PCR method using genus specific ITS and group specific FUM 1 primers. Of the 374 Fusarium isolates tested with ITS set of primers, all fusaria scored positive, whereas only 244 (65%) isolates tested positive with the FUM 1 set of primers. The specificity of the primers provides the basis for a simple, accurate and precise detection of Fusarium species that represents fumonisin producers, which are a considerable risk for animal, poultry and human health.