Substitution of critical isoleucines in the KH domains of Drosophila fragile X protein results in partial loss-of-function phenotypes

Fragile X mental retardation proteins (FMRP) are RNA-binding proteins that interact with a subset of cellular RNAs. Several RNA-binding domains have been identified in FMRP, but the contribution of these individual domains to FMRP function in an animal model is not well understood. In this study, we have generated flies with point mutations in the KH domains of the Drosophila melanogaster fragile X gene (dfmr1) in the context of a genomic rescue fragment. The substitutions of conserved isoleucine residues within the KH domains with asparagine are thought to impair binding of RNA substrates and perhaps the ability of FMRP to assemble into mRNP complexes. The mutants were analyzed for defects in development and behavior that are associated with deletion null alleles of dfmr1. We find that these KH domain mutations result in partial loss of function or no significant loss of function for the phenotypes assayed. The phenotypes resulting from these KH domain mutants imply that the capacities of the mutant proteins to bind RNA and form functional mRNP complexes are not wholly disrupted and are consistent with biochemical models suggesting that RNA-binding domains of FMRP can function independently.     

Molecular methods for diagnosis of Entamoeba histolytica in a clinical setting: an overview

The range of clinical outcomes following Entamoeba histolytica infection is likely to be influenced by the different strains of the parasite already existing in our population. There is a need for developing faster, reliable and reproducible methods for identifying the different strains of E. histolytica. This would have a major impact on the subsequent course of treatment given to patients. In the post-genomic era, different loci of the Entamoeba genome have been targeted for developing suitable probes and genetic markers. This review highlights the development made in this direction and the possibility of using these methods for routine testing of this parasite in clinical samples.     

Co-Carriage of bla KPC-2 and bla NDM-1 in Clinical Isolates of Pseudomonas aeruginosa Associated with Hospital Infections from India

Global spread of KPC poses to be a serious threat complicating treatment options in hospital settings. The present study investigates the genetic environment of bla _KPC-2 among clinical isolates of Pseudomonas aeruginosa from a tertiary referral hospital of India. The study isolates were collected from different wards and clinics of Silchar Medical College and Hospital, India, from 2012–2013. The presence of bla _KPC was confirmed by genotypic characterization followed by sequencing. Cloning of the bla _KPC-2 gene was performed and the genetic environment of this gene was characterized as well. Transferability of the resistance gene was determined by transformation assay and Southern hybridization. Additionally, restriction mapping was also carried out. Two isolates of P. aeruginosa were found to harbor bla _KPC-2, were resistant towards aminoglycosides, quinolone and β-lactam-β-lactamase inhibitor combination. In both the isolates, the resistance determinant was associated with class 1 integron and horizontally transferable. Both the isolates were co-harboring bla _NDM-1. The first detection of this integron mediated bla _KPC-2 coexisting with bla _NDM-1 in P. aeruginosa from India is worrisome, and further investigation is required to track the gene cassette mediated bla _KPC-2 in terms of infection control and to prevent the spread of this gene in hospitals as well as in the community.     

cAMP production by adenylyl cyclase G induces prespore differentiation in Dictyostelium slugs

Encystation and sporulation are crucial developmental transitions for solitary and social amoebae, respectively. Whereas little is known of encystation, sporulation requires both extra- and intracellular cAMP. After aggregation of social amoebae, extracellular cAMP binding to surface receptors and intracellular cAMP binding to cAMP-dependent protein kinase (PKA) act together to induce prespore differentiation. Later, a second episode of PKA activation triggers spore maturation. Adenylyl cyclase B (ACB) produces cAMP for maturation, but the cAMP source for prespore induction is unknown. We show that adenylyl cyclase G (ACG) protein is upregulated in prespore tissue after aggregation. acg null mutants show reduced prespore differentiation, which becomes very severe when ACB is also deleted. ACB is normally expressed in prestalk cells, but is upregulated in the prespore region of acg null structures. These data show that ACG induces prespore differentiation in wild-type cells, with ACB capable of partially taking over this function in its absence.     

Kinetic resolution of (+/-)-1-phenylethanol in [Bmim][PF6] using high activity preparations of lipases

Lipases from two different sources Candida rugosa (CRL) and Burkholderia cepacia (BCL) were formulated as enzyme precipitated and rinsed with organic solvents, organic solvent rinsed enzyme preparation, cross-linked enzyme aggregates (CLEAs) and protein coated micro-crystals (PCMCs). These various enzyme formulates were evaluated for the kinetic resolution of (+/-)-1-phenylethanol in ionic liquid [Bmim][PF(6)] by transesterification with vinyl acetate. Of all the enzyme forms evaluated EPRP and PCMC in the case of CRL showed the best results with 26 % (E value=153) and 53% (E value=79) conversion, respectively, at 35 degrees C in 24h. Carrying out this conversion with PCMC at lower temperature of 25 degrees C further improved the E value to 453 (with 44% conversion in 12h). For BCL the acetone-rinsed enzyme preparation (AREP), CLEA and PCMC performed equally well with % conversion of 50 and 99 ee(p) (%) (E value >1000) in just 2h, whereas, the free lipase gave only 8% conversion.     

Enhancement of wood waste decomposition by microbial inoculation prior to vermicomposting

To investigate the feasibility of microbial pre-decomposition of timber wastes to quality production of vermicompost with higher agronomic value, timber wastes were inoculated with different combinations of the fungi Phanerochete chrysosporium, Trichoderma reesei, Aspergillus niger and the bacteria Azotobacter chroococcum (MTCC 3853) and Bacillus cereus (MTCC 4079) and incubated at 28-30 °C in a mechanical composter. The inoculation enhanced the degradation of timber wastes, increased total nitrogen and improved the quality and enhanced production of vermicompost generated with the native earthworm Drawida willsi Michelsen. Total nitrogen increased from 0.16% to 1.52% and total organic carbon (TOC) decreased from 42% to 13%. Out of 10 microbial combinations tested for pre-decomposition, the combination of P. chrysosporium+T. reesei was found best in terms of ligno-cellulosic decomposition, and P. chrysosporium+A. niger+B. cereus with respect of cast output. The study shows that microbial pre-decomposition of timber wastes to produce quality vermicompost is a feasible technology.