Praealbonemertes whangateaunienses n. gen. and n. sp., a new heteronemertean from New Zealand

Abstract

A new genus and species of heteronemertean, Praealbonemertes whangateaunienses n. gen. and n. sp., is described and illustrated. The species is characterised by inter alia a cephalic lacuna with strands of longitudinal muscle fibres, a proboscis with three muscle layers, and a well-developed muscle plate dorsal to the foregut and anterior intestine. The material was collected in New Zealand.     

Preparation and characterisation of gelatine from the skin of harp seal (Phoca groendlandica)

This paper describes a method for extraction of gelatine from the skin of harp seal at mild acid conditions and gives a chemical and physical comparison of this gelatine with other mammalian and cod-skin gelatines. As compared to the wet weight of unhaired skin, a recovery of 11% dry gelatine was achieved after acid treatment and a two step water extraction at 60 and 75 degrees C. The chemical and physical properties of the gelatine were similar to the properties of commercial gelatines made from bovine and porcine skin, but significantly different from the properties of Atlantic cod-skin gelatine. The results indicated that seal skin gelatine can be used as a substitute for standard commercial gelatines for food technology applications.     

Seasonal Changes in Osmotic and Ionic Regulation in Arctic Charr, Salvelinus Alpinus, From a High- and a Sub-arctic Anadromous Population

Seasonal changes in hypoosmoregulatory capacity were studied in hatchery-reared offspring of a high-Arctic strain of anadromous Arctic charr, Salvelinus alpinus, from Svalbard (79°N) and a sub-Arctic strain from Hammerfest, north Norway (70°N). The fish were held in freshwater under simulated, natural light conditions (Tromsø, 69°N) and natural water temperatures, and hypoosmoregulatory capacity was determined by seawater challenge tests between February and November. An improved hypoosmoregulatory capacity was seen in both strains at the time when their wild conspecifics migrate to the sea. The time when maximum hypoosmoregulatory capacity was achieved differed significantly between the two strains, suggesting that there may be genetic differences between the two populations in how environmental cues (e.g. temperature, photoperiod) entrain the development of seawater tolerance. The development and loss of hypoosmoregulatory capacity seemed to be more rapid and abrupt in the Svalbard charr than in the Hammerfest charr. This is hypothesised to be an adaptation to the stochastic and unpredictable variations in the time when the fish are allowed to migrate in the high-Arctic, and the need to prevent migration in years when the ice break occurs very late.     

A Genome-wide Association Study of Lung Cancer Identifies a Region of Chromosome 5p15 Associated with Risk for Adenocarcinoma

Three genetic loci for lung cancer risk have been identified by genome-wide association studies (GWAS), but inherited susceptibility to specific histologic types of lung cancer is not well established. We conducted a GWAS of lung cancer and its major histologic types, genotyping 515,922 single-nucleotide polymorphisms (SNPs) in 5739 lung cancer cases and 5848 controls from one population-based case-control study and three cohort studies. Results were combined with summary data from ten additional studies, for a total of 13,300 cases and 19,666 controls of European descent. Four studies also provided histology data for replication, resulting in 3333 adenocarcinomas (AD), 2589 squamous cell carcinomas (SQ), and 1418 small cell carcinomas (SC). In analyses by histology, rs2736100 (TERT), on chromosome 5p15.33, was associated with risk of adenocarcinoma (odds ratio [OR] = 1.23, 95% confidence interval [CI] = 1.13–1.33, p = 3.02 × 10⁻⁷), but not with other histologic types (OR = 1.01, p = 0.84 and OR = 1.00, p = 0.93 for SQ and SC, respectively). This finding was confirmed in each replication study and overall meta-analysis (OR = 1.24, 95% CI = 1.17–1.31, p = 3.74 × 10⁻¹⁴ for AD; OR = 0.99, p = 0.69 and OR = 0.97, p = 0.48 for SQ and SC, respectively). Other previously reported association signals on 15q25 and 6p21 were also refined, but no additional loci reached genome-wide significance. In conclusion, a lung cancer GWAS identified a distinct hereditary contribution to adenocarcinoma.     

Structure of a ternary Naa50p (NAT5/SAN) N-terminal acetyltransferase complex reveals the molecular basis for substrate-specific acetylation

The co-translational modification of N-terminal acetylation is ubiquitous among eukaryotes and has been reported to have a wide range of biological effects. The human N-terminal acetyltransferase (NAT) Naa50p (NAT5/SAN) acetylates the α-amino group of proteins containing an N-terminal methionine residue and is essential for proper sister chromatid cohesion and chromosome condensation. The elevated activity of NATs has also been correlated with cancer, making these enzymes attractive therapeutic targets. We report the x-ray crystal structure of Naa50p bound to a native substrate peptide fragment and CoA. We found that the peptide backbone of the substrate is anchored to the protein through a series of backbone hydrogen bonds with the first methionine residue specified through multiple van der Waals contacts, together creating an α-amino methionine-specific pocket. We also employed structure-based mutagenesis; the results support the importance of the α-amino methionine-specific pocket of Naa50p and are consistent with the proposal that conserved histidine and tyrosine residues play important catalytic roles. Superposition of the ternary Naa50p complex with the peptide-bound Gcn5 histone acetyltransferase revealed that the two enzymes share a Gcn5-related N-acetyltransferase fold but differ in their respective substrate-binding grooves such that Naa50p can accommodate only an α-amino substrate and not a side chain lysine substrate that is acetylated by lysine acetyltransferase enzymes such as Gcn5. The structure of the ternary Naa50p complex also provides the first molecular scaffold for the design of NAT-specific small molecule inhibitors with possible therapeutic applications.     

Molecular cloning,expression and characterization of Pekin duck interferon-λ

Interferons (IFNs) are the first line of defense against viral infections in vertebrates. Type III interferon (IFN-λ) is recognized for its key role in innate immunity of tissues of epithelial origin. Here we describe the identification of the Pekin duck IFN-λ ortholog (duIFN-λ). The predicted duIFN-λ protein has an amino acid identity of 63%, 38%, 37% and 33% with chicken IFN-λ and human IFN-λ3, IFN-λ2 and IFN-λ1, respectively. The duck genome contains a single IFN-λ gene that is comprised of five exons and four introns. Recombinant duIFN-λ up-regulated OASL and Mx-1 mRNA in primary duck hepatocytes. Our observations suggest evolutionary conservation of genomic organization and structural features implicated in receptor binding and antiviral activity. The identification and expression of duIFN-λ will facilitate further study of the role of type III IFN in antiviral defense and inflammatory responses of the Pekin duck, a non-mammalian vertebrate and pathogen host with relevance for human and animal health.     

State-dependent feed acquisition among two strains of hatchery-reared Arctic charr

The effects of genetic and environmental factors on aggression and feeding hierarchies were studied using X-radiography to measure food intake by hatchery-reared individuals of two strains (Hammerfest and Svalbard) of Arctic charr Salvelinus alpinus . A reduction in food rations and/or water current speed increased intraspecific aggression, and both factors led to increased interindividual variability in food intake, increasing the coefficient of variation (CV). Following a return to pre-manipulation conditions, CVs decreased to their original level. In control groups, CVs and share of group meals were stable throughout the experiment. The increase in CVs following manipulation was the result of a small number of dominant individuals obtaining a high share of the meal. Restriction in food ration affected share of meals, specific growth rates and the frequencies of non-feeding fish, while reductions in water current speed affected only share of meals. Feeding hierarchies were size-dependent in the control groups. In contrast, no relationships between body weight and feeding rank were evident in groups in which food ration or water current speed were reduced. A small, but consistent, difference was revealed in feeding hierarchy responses between the two strains.