Genome-wide expression analysis of roxarsone-stimulated growth of broiler chickens (Gallus gallus)

Roxarsone is a commonly used additive in chicken (Gallus gallus) industry. However, little is known on the intrinsic molecular mechanism via which the growth performance of birds improves. This study was therefore performed to investigate the expression profiles of genes induced by roxarsone. Fifty-six broiler chickens were divided into two groups, namely treated and untreated with roxarsone. The treated group was provided a diet of 45.4 mg/kg roxarsone medication and the other group acted as control. Data analysis showed that roxarsone consistently and significantly (P < 0.05) increased chicken growth performance. In addition to this a significant (P < 0.05) increase of arsenic residue in liver has been seen. Microarray expression analysis of 8935 genes in liver showed that 22 genes (10 up- and 12 down-regulated) had altered expression throughout the experimental periods. Two novel genes (GenBank accession no. GU724343 and GU724344) were cloned through rapid amplification of cDNA ends (RACE). Gene GU724343 was predicted to encode an unidentified protein and the second gene GU724344 was presumed to encode a new member of immunoglobulin-like receptor (CHIR) family. Our results suggested for the first time that the role of roxarsone could be mainly to modify the expression levels of cell growth, immunity/defense and energy metabolism associated genes, as a result promoting animal growth. Further research on these genes should help to increase the knowledge of improving animal productivity safely and effectively.     

Expression of an anti apoptotic recombinant short peptide in mammalian cells

Understanding the mechanisms of the apoptotic and anti apoptotic processes may lead to a better way to control these cascades. Here we demonstrated for the first time the feasibility to express a short functional peptide in mammalian cells that abrogates the apoptosis cascade through interference with the proteolytic activity of the initiator caspase 9 and the executing caspase 3 enzymes. The expression of a short peptide that includes the pseudo-substrate motif of the apoptosis inhibitor protein P35 (Asp-Gln-Met-Asp) leads to the abrogation of cell death induced through either the mitochondrial or the death receptors pathways.Short open reading frames have been detected in several mammalian mRNAs, primarily upstream of the main long reading frame (uORFs), however, direct evidence for de-novo peptides translation has not been provided. Utilizing biochemical and imaging techniques we demonstrate here that the functional recombinant peptide was localized to the cytpoplasmic fraction of the cell.In conclusion, this work demonstrates that ribosomes recognize short ORFs to translate stable short recombinant peptides in mammalian cells. Expression of these intracellular peptides results in the knock down of apoptotic processes to generate apoptosis resistant stable cells.     

Atrazine degradation by encapsulated Rhodococcus erythropolis NI86/21

AIMS: To develop an encapsulation procedure for Rhodococcus erythropolis NI86/21 and demonstrate its use as a slow-release inoculant for reducing atrazine levels in aquatic and terrestrial environments. METHODS AND RESULTS: Alginate encapsulation procedures were developed for the atrazine-degrading bacteria R. erythropolis NI86/21. Several bead amendments, including bentonite, powdered activated carbon (PAC) and skimmed milk (SM), were evaluated for slow release of R. erythropolis NI86/21 and efficacy of atrazine degradation. All bead types demonstrated a capacity to degrade atrazine in basal minimal nutrient buffer whilst continually releasing viable bacterial cells. We found that the addition of bentonite hastened cell release whilst SM sustained cell viability in bead formulations. Reducing the percentage of SM to 1% (w/v) resulted in faster rates of atrazine degradation in both liquid and soil, and was found to prolong cell survival upon bead storage. Limited oxygen transfer affects the capacity of the encapsulated R. erythropolis cells to degrade atrazine. CONCLUSIONS: Degradation studies have demonstrated the efficacy of R. erythropolis encapsulated cells to degrade atrazine in amended liquid and soil. However, in their current formulation, the wet alginate-based beads are impractical for field application because of their poor cell viability during storage. SIGNIFICANCE AND IMPACT OF THE STUDY: R. erythropolis NI86/21-encapsulated cells have the potential to reduce atrazine residues in a number of soil and water environments, possibly ensuring the continued registration and use of atrazine in agriculture by minimizing or eliminating nontarget effects.     

A cDNA encoding diazepam-binding inhibitor/acyl-CoA-binding protein in Helicoverpa armigera: molecular characterization and expression analysis associated with pupal diapause

The diazepam binding inhibitor (DBI) or the acyl-CoA-binding protein (ACBP) is a 9-10 kDa highly conserved multifunctional protein that plays important roles in GABA(A) receptor activity regulation, lipid absorption and steroidogenesis in various organisms. To study the functions of DBI/ACBP in insect development or diapause, we cloned the cDNA from Helicoverpa armigera (Har) utilizing rapid amplification of cDNA ends (RACE). By homology search, Har-DBI/ACBP is conserved with the DBI/ACBPs known from other insects. Northern blot analysis showed that DBI/ACBP gene expressed in nonneural and neural tissues. RT-PCR combined Southern blot analysis revealed that DBI/ACBP mRNA in the brain of nondiapause individual was much higher than that in the brain of diapausing insects. At early and middle stages of 6th instar larvae, the level of DBI/ACBP mRNA was higher in the midgut of diapause type than that in nondiapause type and low at late 6th instar larval stage and early pupal stage in both types. In the prothoracic gland (PG), DBI/ACBP expression appeared at a high level at middle and late stages of 6th larval instar in both nondiapause and diapause types, and declined after pupation. In vitro experiments revealed that DBI/ACBP mRNA in PG could be stimulated by synthetic H. armigera diapause hormone (Har-DH), suggesting that Har-DH may stimulate the PG to produce ecdysteroids by the DBI/ACBP signal pathway. By in vitro assay, we also found that FGIN-1-27, which has similar functions to DBI/ACBP in ecdysteroidogenesis, could induce PG ecdysteroidogenesis effectively, suggesting that DBI/ACBP regulates biosynthesis of ecdysteroids in PG. Thus, DBI/ACBP indeed plays a key role in metabolism and development in H. armigera.     

Changes of enzyme activity in lipid signaling pathways related to substrate reordering

The static fluid mosaic model of biological membranes has been progressively complemented by a dynamic membrane model that includes phospholipid reordering in domains that are proposed to extend from nanometers to microns. Kinetic models for lipolytic enzymes have only been developed for homogeneous lipid phases. In this work, we develop a generalization of the well-known surface dilution kinetic theory to cases where, in a same lipid phase, both domain and nondomain phases coexist. Our model also allows understanding the changes in enzymatic activity due to a decrease of free substrate concentration when domains are induced by peptides. This lipid reordering and domain dynamics can affect the activity of lipolytic enzymes, and can provide a simple explanation for how basic peptides, with a strong direct interaction with acidic phospholipids (such as beta-amyloid peptide), may cause a complex modulation of the activities of many important enzymes in lipid signaling pathways.     

MDR-like ABC transporter AtPGP4 is involved in auxin-mediated lateral root and root hair development

Previous data have suggested an involvement of MDR/PGP-like ABC transporters in transport of the plant hormone auxin and, recently, AtPGP1 has been demonstrated to catalyze the primary active export of auxin. Here we show that related isoform AtPGP4 is expressed predominantly during early root development. AtPGP4 loss-of-function plants reveal enhanced lateral root initiation and root hair lengths both known to be under the control of auxin. Further, atpgp4 plants show altered sensitivities toward auxin and the auxin transport inhibitor, NPA. Finally, mutant roots reveal elevated free auxin levels and reduced auxin transport capacities. These results together with yeast growth assays suggest a direct involvement of AtPGP4 in auxin transport processes controlling lateral root and root hair development.     

Interactome modeling

A long-term goal of the field of interactome modeling is to understand how global and local properties of complex macromolecular networks impact on observable biological properties, and how changes in such properties can lead to human diseases. The information available at this stage of development of the field provides strong evidence for the existence of such interesting global and local properties, but also demonstrates that many more datasets will be needed to provide accurate models with increasingly predictive capacity. This review focuses on an early attempt at mapping a multicellular interactome network and on the lessons learned from that attempt.     

Blastocladiella emersonii expresses a centrin similar to Chlamydomonas reinhardtii isoform not found in late-diverging fungi

Centrins are members of the calcium-binding EF-hand protein superfamily which can be divided into two subfamilies, probably associated with different functions: one related to Chlamydomonas reinhardtii centrin, CrCenp, and the other, represented by Saccharomyces cerevisiae isoform, ScCdc31p. ESTs encoding the two isoforms (BeCen1 and BeCen3) from the chytridiomycete Blastocladiella emersonii were isolated, and expression of the CrCenp-type centrin, BeCen1, was analyzed throughout the fungus life cycle. Becen1 mRNA levels increase transiently during sporulation and protein levels present a similar pattern. Immunolocalization studies seem to localize BeCen1 at the basal body zone and in the cytoplasm surrounding the nuclear cap, a zoospore organelle.