Anthropocene invasion of an ecosystem engineer: resolving the history of Corophium volutator (Amphipoda: Corophiidae) in the North Atlantic

Resolving the natural histories of species is important for the interpretation of ecological patterns, as it provides evolutionary context for the interactions between organisms and their environment. Despite playing an integral role on the intertidal mudflats of the North Atlantic as an abundant food source for predators and as an ecosystem engineer that alters the soft sediment environment, no previous studies have provided empirical evidence to determine the biogeographical origin of the amphipod Corophium volutator. To resolve its status as introduced or indigenous in Europe and North America, we analyzed sequence data for two mitochondrial loci and two nuclear markers, aiming to determine whether the present range of C. volutator is the result of unresolved taxonomy, persistence in glacial refugia, natural trans‐Atlantic dispersal, or human‐mediated introduction. Our results demonstrate a reduced genetic diversity in North American populations that is a subsample of diversity in European populations, with coalescent analyses of mitochondrial and nuclear DNA supporting different models of multiple introductions from Europe to the Bay of Fundy and Gulf of Maine in North America. These results suggest that C. volutator was introduced to North America prior to the first surveys of local biota in the 20th Century, which has broad implications for interpretations of community and ecosystem interactions in the North Atlantic intertidal. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 115 , 288–304.     

Hybridization of tRNAs of Drosophila melanogaster to the region of the 5S RNA genes of the polytene chromosomes

We have previously reported that four tRNAs of Drosophila melanogaster randomly labeled with iodine-125 hybridize in part to the 56EF region of polytene chromosomes where 5S RNA genes occur. In the presence of a 100-fold excess of unlabeled 5S RNA no hybridization of randomly labeled ¹²⁵I-tRNA^Asp ₂ occurred at 56EF although hybridization elsewhere was not affected. In addition, tRNA^Asp ₂ labeled by introducing ¹²⁵I-5-iodocytidylyl residues into the 3-CCA end with tRNA nucleotidyl transferase did not hybridize to 56EF but did hybridize to its other sites. The hybridization of tRNA^Lys ₂, tRNA^Gly ₃ and tRNA^Met ₃ at 56EF was not eliminated by a 25 to 100-fold excess of unlabeled 5S RNA. When these tRNAs were labeled at the -CCA terminus they hybridized to 56EF as well as to their other sites with the exception that terminally labeled tRNA^Lys ₂ no longer hybridized to 62A. The hybridization of the latter three species of tRNA to the region of the 5S genes, amongst other sites, is confirmed. The previously observed hybridization of tRNA^Asp ₂ in this region appears to have been due to contamination of the tRNA sample with traces of material derived from 5S RNA.     

Enzyme histochemical properties of kitten osteoclasts in bone imprint preparations

Synopsis The enzyme histochemical characteristics of osteoclasts in imprints of the metaphyseal regions of femurs, from male kittens aged approximately 18 weeks, were investigated. A selected number of enzymes representative of a variety of metabolic pathways were studied. The enzyme profile, time for the first appearance of detectable reaction product, intensity of the reactions, and localization of the reaction products were noted.Osteoclasts are rich in enzymes, and metabolic pathways are well developed in respect of the utilization of the reduced coenzymes NADP and NADPH, succinic, malic, lactic, and isocitric acids, -hydroxybutyrate and glucose-6-phosphate, the reactions being mediated by the diaphorases and dehydrogenases. The activities of acid and neutral phosphatases, non-specific esterases, and leucine naphthylamidase were high in these cells. However, little or no activity was demonstrated in respect of glutamate and -glycerophosphate dehydrogenases or of aryl sulphatase, glucose-6-phosphatase and alkaline phosphatase.     

Advantages in the Use of Aldehyde Fuchsin with Van Gieson's Picro-Fuchsin Counterstaining for Differentiating Bone and Cartilage

Specimens of bone were fixed in 10% neutral phosphate-buffered formalin or in Bouin's fluid and decalcified in 10% formic acid buffered with 10% sodium citrate. Materials were embedded in paraffin and 4-5 μ sections attached to slides were oxidized with 0.5% KMnO₄, decolorized in 1% oxalic acid, stained with aldehyde fuchsin, and counter-stained with Van Gieson's picro-fuchsin. Sections were dehydrated, cleared and mounted in a synthetic resin. Microscopically, the differentiation between bone and cartilage was seen as red and purple respectively, with connective tissue red; muscle and erythrocytes, yellow; and elastic fibres purple. The areas occupied by bone, cartilage and erythrocytes could be compared, and also the depth to which cartilage extended into the ossified sites. The advantages of this staining combination are: good contrasts in colour, ease of applying the stain, and virtual self-differentiation of the staining solutions.     

Reduction of liver macrophage transduction by pseudotyping lentiviral vectors with a fusion envelope from Autographa californica GP64 and Sendai virus F2 domain

Background  

Lentiviral vectors are well suited for gene therapy because they can mediate long-term expression in both dividing and nondividing cells. However, lentiviral vectors seem less suitable for liver gene therapy because systemically administered lentiviral vectors are preferentially sequestered by liver macrophages. This results in a reduction of available virus and might also increase the immune response to the vector and vector products.     

Polyhydroxybutyrate-enhanced transformation of log-phase Escherichia coli

Transformation of Escherichia coli plays an important role in recombinant DNA technology. Most current transformation protocols require that the cells be treated to attain a particular physiological state known as "competence," and this makes transformation procedures lengthy and arduous. Here we describe a protocol for transforming log-phase E. coli using dimethyl sulfoxide (DMSO) solutions of poly-(R)-3-hydroxybutyrate (PHB) to facilitate the transfer of plasmid DNA into cells, and certain reagents and temperature shocks to promote DNA uptake. The protocol was optimized using factorial design techniques across variables that included PHB molecular weight and concentration, DMSO concentration, monovalent and divalent salts, glucose, cold and heat shocks, cell density, and pH. Using 10 ng DNA, the optimized protocol produces approximately 1000 colony-forming units (CFUs) from 100 microL early log-phase cell culture or approximately 300 CFU from a 21-24 h single colony, sufficient for many applications. The total volume of the transformation reaction mixture is only 150 microL suggesting that the procedure may be adapted for use in microplates or automated transformation technologies.     

Distribution of delta-aminolevulinic acid synthetase and delta-aminolevulinic acid dehydratase in liver and kidney of rainbow trout (Salmo gairdnerii)

1. Activities of delta-aminolevulinic acid synthetase (ALA-S) and delta-aminolevulinic acid dehydratase (ALA-D) in trout liver and kidney were compared with those in the mouse. 2. ALA-S activity (per unit tissue fresh weight) exceeded ALA-D activity in trout liver and kidney. 3. In trout kidney, ALA-S activity slightly exceeded, and ALA-D activity far exceeded, their activities in trout liver. 4. In trout, heme synthesis differs from that in mammals in that appreciable synthesis occurs in the kidney, and in that ALA-S activity is not rate limiting.     

Primary structure of the Neurospora plasma membrane H+-ATPase deduced from the gene sequence. Homology to Na+/K+-, Ca2+-, and K+-ATPase

The gene for the Neurospora crassa plasma membrane H+-ATPase has been cloned and sequenced. The gene encodes for a protein of 920 amino acids with a molecular weight of 100,002. The coding region is interrupted by four introns: three near the amino terminus and one near the carboxyl terminus. The deduced amino acid sequence of the N. crassa plasma membrane H+-ATPase exhibits 75% homology to the amino acid sequence of the Saccharomyces cerevisiae plasma membrane H+-ATPase. Also, an amino acid comparison with the Na+/K+-ATPase from sheep kidney, Ca2+-ATPase from rabbit muscle, and K+-ATPase from Escherichia coli reveals that certain regions are highly conserved and suggest that these regions may serve essential functions which are common to the various cation-motive ATPases. This observation suggests that the phosphorylatable, cation-motive ATPases may function via a similar energy transduction mechanism.     

ProADD: A database on Protein Aggregation Diseases

ProADD, a database for protein aggregation diseases, is developed to organize the data under a single platform to facilitate easy access for researchers. Diseases caused due to protein aggregation and the proteins involved in each of these diseases are integrated. The database helps in classification of proteins involved in the protein aggregation diseases based on sequence and structural analysis. Analysis of proteins can be done to mine patterns prevailing among the aggregating proteins.

Availability

http://bicmku.in/ProADD