The proliferative state,graft-site and contact-time of competent chick ectoblast determine the quality and quantity of neural induction by Hensen's node

We have assessed the type and amount of neural tissue induced in the chick gastrula ectoblast with increasing duration of contact with the Hensen node inducer. At least 4 h contact is necessary to induce the ectoblast in the area pellucida, 9 h in the area opaca and even longer at the margin of overgrowth. In the area pellucida, the inductive response shifts from archencephalic type at 4-6 h contact to deuterencephalic type after 9 h contact. The induced tissue volume and cell number increased as graft-host contact increased from 4-9 h, and then decreased with longer contact. We suggest that in addition to the period of contact and the grafting position on competent ectoblast, the rate of cell proliferation may control the axial specificity and morphological organization of the induced neural tissue.     

Restriction-modification system in bacteriophage MB78

Restriction-modification system is present in bacteria to protect the cells against phage infection. Interestingly, the bacteriophage MB78, a virulent phage of Salmonella typhimurium possesses restriction-modification system. Permissive host transformed with plasmid having the genomic fragment of MB78 carrying the putative restriction-modification genes severely restrict the growth of the phage 9NA. Growth of phage MB78 is also restricted to some extent. However, the temperate phage P22 is not restricted at all. Cloning of the the putative restriction-modification genes has been done in both orientations in different vectors. The clones carrying the genes in the same orientation as that of the lacZ in pUC19 are mostly unstable. However, those are stable when cloned in opposite orientation. Viability of the transformants is strain-, orientation-, and medium-dependent. The two genes have also been cloned individually/separately. Hosts carrying only the modification gene do not restrict growth of phages while the hosts carrying only the restriction gene do. The former produces stable transformants while the latter produces very unstable transformants which were viable only upto 36 h or so. The colonies carrying modification gene were normal looking while those carrying the restriction gene were tiny, flat, and looked distressed resembling very much the clones carrying bacterial restriction-modification system. Amplification of the genes and subsequent cloning in expression vector will be carried out for characterization of the enzymes.     

Synthesis of glycosylated beta-amino hydroxamates as new class of antimalarials

Glycosylated β-amino acids (3–18, 38, 39), obtained by hydrolysis of glycosylated β-amino esters on reaction with hydroxylamine hydrochloride in presence of DIC/DCC afforded glycosyl β-amino hydroxamates (19–34, 40, 41) in fair to good yields. Compounds (19–34, 40, 41) were screened against human malarial parasite Plasmodium falciparum in vitro for their schizontocidal activity. Compounds (19, 24, 26, 28, 40 and 41) exhibited good activity at 2 μg/mL concentrations.     

Double heterozygous hemoglobin Q India/hemoglobin D Punjab hemoglobinopathy: Report of two rare cases

Cation exchange high performance liquid chromatography (CE HPLC) provides an excellent tool for accurate and reliable diagnosis of various hemoglobin (Hb) disorders. HbQ India is a rare alpha chain variant that usually presents in the heterozygous state. Its presence in double heterozygous state with HbD Punjab is extremely rare. The double heterozygosity for α and β chain variants leads to formation of abnormal heterodimer hybrids, which can lead to diagnostic dilemmas. We report two rare cases of double heterozygous HbQ India/HbD Punjab where the hybrid Hb was seen to elute at retention time similar to HbC on CE HPLC. The first case had unconjugated hyperbilirubinemia at presentation; while, the second case was asymptomatic.     

A novel halotolerant xylanase from marine isolate Bacillus subtilis cho40: gene cloning and sequencing

Although several xylanases have been studied, only few xylanases from marine micro-organisms have been reported. We report here a novel halotolerant xylanase from marine bacterium Bacillus subtilis cho40 isolated from Chorao island of mandovi estuary Goa, India. Extracellular xylanase was produced by using agricultural residue such as wheat bran as carbon source under solid-state fermentation (SSF). The optimal pH and temperature of xylanase were reported to be 6.0 and 60°C, respectively. Xyn40 was highly salt-tolerant, and showed highest activity at 0.5M NaCl. Xylanase activity was greatly induced (140%) when pre-incubated with 0.5M NaCl for 4h. The xylanase gene, xyn40, from marine bacterium B. subtilis cho40 was cloned, and expressed in Escherichia coli. The xylanase gene was 645 bp long and had a 215 amino acid ORF protein with a molecular mass of 22.9 kDa. It had all features of xylanase enzyme and showed homology to xylanases reported from B. subtilis. It differs from the earlier reported xylanase sequences by the presence of more serine residues compared to threonine and also by the presence of polar (hydrophilic) amino acids in higher abundance (61%) than non-polar amino acids (39%). The novel xylanase, reported in this study is a halotolerant enzyme from marine isolate and can play a very important role in bioethanol production from marine seaweeds.     

Luminescence,circular dichroism and in silico studies of binding interaction of synthesized naphthylchalcone derivatives with bovine serum albumin

Chalcones possess various biological properties, for example, antimicrobial, anti‐inflammatory, analgesic, antimalarial, anticancer, antiprotozoal and antitubercular activity. In this study, naphthylchalcone derivatives were synthesized and characterized using ¹H NMR ¹³C NMR, Fourier transform infrared and mass techniques. Yields for all derivatives were found to be >90%. Protein–drug interactions influence the absorption, distribution, metabolism and excretion (ADME) properties of a drug. Therefore, to establish whether the synthesized naphthylchalcone derivatives can be used as drugs, their binding interaction toward a serum protein (bovine serum albumin) was investigated using fluorescence, circular dichroism and molecular docking techniques under physiological conditions. Fluorescence quenching of the protein in the presence of naphthylchalcone derivatives, and other derived parameters such as association constants, number of binding sites and static quenching involving confirmed non‐covalent binding interactions in the protein–ligand complex were observed. Circular dichroism clearly showed changes in the secondary structure of the protein in the presence of naphthylchalcones, indicating binding between the derivatives and the serum protein. Molecular modelling further confirmed the binding mode of naphthylchalcone derivatives in bovine serum albumin. A site‐specific molecular docking study of naphthylchalcone derivatives with serum albumin showed that binding took place primarily in the aromatic low helix and then in subdomain II. The dominance of hydrophobic, hydrophilic and hydrogen bonding was clearly visible and was responsible for stabilization of the complex.     

Next generation sequencing of Apis mellifera syriaca identifies genes for Varroa resistance and beneficial bee keeping traits

Apis mellifera syriaca exhibits a high degree of tolerance to pests and pathogens including varroa mites. This native honey bee subspecies of Jordan expresses behavioral adaptations to high temperature and dry seasons typical of the region. However, persistent honey bee imports of commercial breeder lines are endangering local honey bee population. This study reports the use of next‐generation sequencing (NGS) technology to study the A. m. syriaca genome and to identify genetic factors possibly contributing toward mite resistance and other favorable traits. We obtained a total of 46.2 million raw reads by applying the NGS to sequence A. m. syriaca and used extensive bioinformatics approach to identify several candidate genes for Varroa mite resistance, behavioral and immune responses characteristic for these bees. As a part of characterizing the functional regulation of molecular genetic pathway, we have mapped the pathway genes potentially involved using information from Drosophila melanogaster and present possible functional changes implicated in responses to Varroa destructor mite infestation toward this. We performed in‐depth functional annotation methods to identify ～600 candidates that are relevant, genes involved in pathways such as microbial recognition and phagocytosis, peptidoglycan recognition protein family, Gram negative binding protein family, phagocytosis receptors, serpins, Toll signaling pathway, Imd pathway, Tnf, JAK‐STAT and MAPK pathway, heamatopioesis and cellular response pathways, antiviral, RNAi pathway, stress factors, etc. were selected. Finally, we have cataloged function‐specific polymorphisms between A. mellifera and A. m. syriaca that could give better understanding of varroa mite resistance mechanisms and assist in breeding. We have identified immune related embryonic development (Cactus, Relish, dorsal, Ank2, baz), Varroa hygiene (NorpA2, Zasp, LanA, gasp, impl3) and Varroa resistance (Pug, pcmt, elk, elf3‐s10, Dscam2, Dhc64C, gro, futsch) functional variations genes between A. mellifera and A. m. syriaca that could be used to develop an effective molecular tool for bee conservation and breeding programs to improve locally adapted strains such as syriaca and utilize their advantageous traits for the benefit of apiculture industry.     

Altered synaptic properties during integration of adult-born hippocampal neurons following a seizure insult

Pathological conditions affect several stages of neurogenesis in the adult brain, including proliferation, survival, cell fate, migration, and functional integration. Here we explored how a pathological environment modulates the heterogeneous afferent synaptic input that shapes the functional properties of newly formed neurons. We analyzed the expression of adhesion molecules and other synaptic proteins on adult-born hippocampal neurons formed after electrically-induced partial status epilepticus (pSE). New cells were labeled with a GFP-retroviral vector one week after pSE. One and three weeks thereafter, synaptic proteins were present on dendritic spines and shafts, but without differences between pSE and control group. In contrast, at six weeks, we found fewer dendritic spines and decreased expression of the scaffolding protein PSD-95 on spines, without changes in expression of the adhesion molecules N-cadherin or neuroligin-1, primarily located at excitatory synapses. Moreover, we detected an increased expression of the inhibitory scaffolding protein gephyrin in newborn but not mature neurons after SE. However, this increase was not accompanied by a difference in GABA expression, and there was even a region-specific decrease in the adhesion molecule neuroligin-2 expression, both in newborn and mature neurons. Neuroligin-2 clusters co-localized with presynaptic cholecystokinin terminals, which were also reduced. The expression of neuroligin-4 and glycine receptor was unchanged. Increased postsynaptic clustering of gephyrin, without an accompanying increase in GABAergic input or neuroligin-2 and -4 expression, the latter important for clustering of GABA(A) and glycine receptors, respectively, could imply an increased but altered inhibitory connectivity specific for newborn neurons. The changes were transient and expression of both gephyrin and NL-2 was normalized 3 months post-SE. Our findings indicate that seizure-induced brain pathology alters the sub-cellular expression of synaptic adhesion molecules and scaffolding proteins related to particularly inhibitory but also excitatory synapses, which may yield functional consequences for the integration of adult-born neurons.     

Proliferation of Myoblast Skeletal Cells on Three-Dimensional Supermacroporous Cryogels

Cardiac and skeletal muscle tissue engineering provides a smart approach to overcome problems associated with organ transplantation and cardiac tissue and also lays a platform for superior alternative approaches in muscle regeneration. The aim of the study was to demonstrate cryogel scaffold potential in the field of skeletal muscle and cardiac tissue engineering. Poly-hydroxyethyl methacrylate (pHEMA)-gelatin cryogel scaffold was synthesized using cryogelation technique and such a designed material is being reported first time. Rheology study of the pHEMA-gelatin (HG) suggested that the cryogel scaffolds were stable at different temperatures and phase angle remained constant in both dry and wet state. HG cryogel was able to bear increased stress without leading to deformation. Monitoring the hydration of HG scaffold showed shift from a stiff to a more pliable material and upon continuing hydration, shear modulus remained constant with no further change observed. However, the change in phase angle <0.24º indicates a gradual increase in stiffness of the material over time. Scaffold synthesised using such polymer combinations gave cells a native environment for proliferation and surface stiffness have shown to help in differentiation of the cells. Myoskeletal cell lines were cultured on these scaffolds to check the biocompatibility and cell proliferation. Alamar blue assay performed over a period of 3 weeks analysed the metabolic activity of cells which showed more than 60% increase in the total cellular activity. DNA content of cells was found to be directly related to number of cells present at a given time point and this was found to have increased by more than 50% in 3 weeks. Since in 3-D scaffold the surface area is more in comparison to 2-D, hence better cell proliferation is observed. Hoechst and DAPI staining showed tubular structure and alignment of the cells during formation of the tubules shows promising cellular response to the cryogel matrix. The mechanical strength, stiffness and elastic measurements of the scaffold indicated potential application of these materials for skeletal and cardiac tissue engineering.