Characterization of the C. elegans erlin homologue

Background  

Erlins are highly conserved proteins associated with lipid rafts within the endoplasmic reticulum (ER). Biochemical studies in mammalian cell lines have shown that erlins are required for ER associated protein degradation (ERAD) of activated inositol-1,4,5-trisphosphate receptors (IP3Rs), implying that erlin proteins might negatively regulate IP3R signalling. In humans, loss of erlin function appears to cause progressive intellectual disability, motor dysfunction and joint contractures. However, it is unknown if defects in IP3R ERAD are the underlying cause of this disease phenotype, whether ERAD of activated IP3Rs is the only function of erlin proteins, and what role ERAD plays in regulating IP3R-dependent processes in the context of an intact animal or embryo. In this study, we characterize the erlin homologue of the nematode Caenorhabditis elegans and examine erlin function in vivo. We specifically set out to test whether C. elegans erlin modulates IP3R-dependent processes, such as egg laying, embryonic development and defecation rates. We also explore the possibility that erlin might play a more general role in the ERAD pathway of C. elegans.     

Consequences of concurrent Ascaridia galli and Escherichia coli infections in chickens

   

Three experiments were carried out to examine the consequences of concurrent infections with Ascaridia galli and Escherichia coli in chickens raised for table egg production. Characteristic pathological lesions including airsacculitis, peritonitis and/or polyserositis were seen in all groups infected with E. coli. Furthermore, a trend for increased mortality rates was observed in groups infected with both organisms which, however, could not be confirmed statistically. The mean worm burden was significantly lower in combined infection groups compared to groups infected only with A. galli. It was also shown that combined infections of E. coli and A. galli had an added significant negative impact on weight gain.     

Role of Scrib and Dlg in anterior-posterior patterning of the follicular epithelium during Drosophila oogenesis

Background  

Proper patterning of the follicle cell epithelium over the egg chamber is essential for the Drosophila egg development. Differentiation of the epithelium into several distinct cell types along the anterior-posterior axis requires coordinated activities of multiple signaling pathways. Previously, we reported that lethal(2)giant larvae (lgl), a Drosophila tumor suppressor gene, is required in the follicle cells for the posterior follicle cell (PFC) fate induction at mid-oogenesis. Here we explore the role of another two tumor suppressor genes, scribble (scrib) and discs large (dlg), in the epithelial patterning.     

Evolutionary patterns of two major reproduction candidate genes (Zp2 and Zp3) reveal no contribution to reproductive isolation between bovine species

Background  

It has been established that mammalian egg zona pellucida (ZP) glycoproteins are responsible for species-restricted binding of sperm to unfertilized eggs, inducing the sperm acrosome reaction, and preventing polyspermy. In mammals, ZP apparently represents a barrier to heterospecific fertilization and thus probably contributes to reproductive isolation between species. The evolutionary relationships between some members of the tribe Bovini are complex and highly debatable, particularly, those involving Bos and Bison species for which interspecific hybridization is extensively documented. Because reproductive isolation is known to be a major precursor of species divergence, testing evolutionary patterns of ZP glycoproteins may shed some light into the speciation process of these species. To this end, we have examined intraspecific and interspecific genetic variation of two ZP genes (Zp2 and Zp3) for seven representative species (111 individuals) from the Bovini tribe, including five species from Bos and Bison, and two species each from genera Bubalus and Syncerus.     

Identification of genomic differences between Campylobacter jejuni subsp. jejuni and C. jejuni subsp. doylei at the nap locus leads to the development of a C. jejuni subspeciation multiplex PCR method

Background  

The human bacterial pathogen Campylobacter jejuni contains two subspecies: C. jejuni subsp. jejuni (Cjj) and C. jejuni subsp. doylei (Cjd). Although Cjd strains are isolated infrequently in many parts of the world, they are obtained primarily from human clinical samples and result in an unusual clinical symptomatology in that, in addition to gastroenteritis, they are associated often with bacteremia. In this study, we describe a novel multiplex PCR method, based on the nitrate reductase (nap) locus, that can be used to unambiguously subspeciate C. jejuni isolates.     

Diverse accumulation of several dehydrin-like proteins in cauliflower (Brassica oleracea var. botrytis), Arabidopsis thaliana and yellow lupin (Lupinus luteus) mitochondria under cold and heat stress

Background  

Dehydrins represent hydrophilic proteins acting mainly during cell dehydration and stress response. Dehydrins are generally thermostable; however, the so-called dehydrin-like (dehydrin-related) proteins show variable thermolability. Both groups immunoreact with antibodies directed against the K-segment of dehydrins. Plant mitochondrial dehydrin-like proteins are poorly characterized. The purpose of this study was to extend previous reports on plant dehydrins by comparing the level of immunoprecipitated dehydrin-like proteins in cauliflower (Brassica oleracea var. botrytis), Arabidopsis thaliana and yellow lupin (Lupinus luteus) mitochondria under cold and heat stress.     

Copia and Gypsy retrotransposons activity in sunflower (Helianthus annuus L.)

Background  

Retrotransposons are heterogeneous sequences, widespread in eukaryotic genomes, which refer to the so-called mobile DNA. They resemble retroviruses, both in their structure and for their ability to transpose within the host genome, of which they make up a considerable portion. Copia- and Gypsy-like retrotransposons are the two main classes of retroelements shown to be ubiquitous in plant genomes. Ideally, the retrotransposons life cycle results in the synthesis of a messenger RNA and then self-encoded proteins to process retrotransposon mRNA in double stranded extra-chromosomal cDNA copies which may integrate in new chromosomal locations.     

Genes encoding novel secreted and transmembrane proteins are temporally and spatially regulated during Drosophila melanogaster embryogenesis

Background  

Morphogenetic events that shape the Drosophila melanogaster embryo are tightly controlled by a genetic program in which specific sets of genes are up-regulated. We used a suppressive subtractive hybridization procedure to identify a group of developmentally regulated genes during early stages of D. melanogaster embryogenesis. We studied the spatiotemporal activity of these genes in five different intervals covering 12 stages of embryogenesis.     

The gene transformer-2 of Sciara (Diptera, Nematocera) and its effect on Drosophila sexual development

Background  

The gene transformer-2, which is involved in sex determination, has been studied in Drosophila, Musca, Ceratitis, Anastrepha and Lucilia. All these members of Diptera belong to the suborder Brachycera. In this work, it is reported the isolation and characterisation of genes transformer-2 of the dipterans Sciara ocellaris and Bradysia coprophila (formerly Sciara coprophila), which belong to the much less extensively analysed Sciaridae Family of the Suborder Nematocera, which is paraphyletic with respect to Suborder Brachycera.     

Paracoccidioides brasiliensis pancreatic destruction in Calomys callosus experimentally infected

Background  

The wild rodent Calomys callosus is notably resistant to Trypanosoma cruzi infection. In order to better characterize this animal model for experimental infections, we inoculated C. callosus intraperitoneally with Paracoccidioides brasiliensis, a thermally dimorphic fungus that causes a chronic disease with severe granuloma formation in the mouse and humans. The dissemination of P. brasiliensis cells through the lungs, liver, pancreas, and spleen was assessed by histological analysis.     

Inhibition of cytokinesis by wiskostatin does not rely on N-WASP/Arp2/3 complex pathway

Background  

Cytokinesis is the final step of cell division taking place at the end of mitosis during which the cytoplasmic content and replicated chromosomes of a cell are equally partitioned between the two daughter cells. This process is achieved by the formation and the ingression of an actomyosin contractile ring under the control of equatorial microtubules. The mechanisms of contractile ring formation are not fully understood but involve recruitment of preexisting actin filaments and de novo actin polymerisation.     

Molecular characterization, gene expression and dependence on thyroid hormones of two type I keratin genes (sseKer1 and sseKer2) in the flatfish Senegalese sole (Solea senegalensis Kaup)

Background  

Keratins make up the largest subgroup of intermediate filaments, and, in chordates, represent the most abundant proteins in epithelial cells. They have been associated with a wide range of functions in the cell, but little information is still available about their expression profile and regulation during flatfish metamorphosis. Senegalese sole (Solea senegalensis) is a commercially important flatfish in which no keratin gene has been described yet.     

Processing of predicted substrates of fungal Kex2 proteinases from Candida albicans, C. glabrata, Saccharomyces cerevisiae and Pichia pastoris

Background  

Kexin-like proteinases are a subfamily of the subtilisin-like serine proteinases with multiple regulatory functions in eukaryotes. In the yeast Saccharomyces cerevisiae the Kex2 protein is biochemically well investigated, however, with the exception of a few well known proteins such as the α-pheromone precursors, killer toxin precursors and aspartic proteinase propeptides, very few substrates are known. Fungal kex2 deletion mutants display pleiotropic phenotypes that are thought to result from the failure to proteolytically activate such substrates.     

New probes used for IS1245 and IS1311 restriction fragment length polymorphism of Mycobacterium avium subsp. avium and Mycobacterium avium subsp. hominissuis isolates of human and animal origin in Norway

Background  

Mycobacterium avium is an environmental mycobacterium that can be divided into the subspecies avium, hominissuis, paratuberculosis and silvaticum. Some M. avium subspecies are opportunistic pathogens for animals and humans. They are ubiquitous in nature and can be isolated from natural sources of water, soil, plants and bedding material. Isolates of M. avium originating from humans (n = 37), pigs (n = 51) and wild birds (n = 10) in Norway were examined by IS1245 and IS1311 RFLP using new and specific probes and for the presence of IS901 and ISMpa1 by PCR. Analysis and generation of a dendrogram were performed with the software BioNumerics.