The Asian arowana (Scleropages formosus), one of the world’s most expensive cultivated ornamental fishes, is an endangered species. It represents an ancient lineage of teleosts: the Osteoglossomorpha. Here, we provide a high-quality chromosome-level reference genome of a female golden-variety arowana using a combination of deep shotgun sequencing and high-resolution linkage mapping. In addition, we have also generated two draft genome assemblies for the red and green varieties. Phylogenomic analysis supports a sister group relationship between Osteoglossomorpha (bonytongues) and Elopomorpha (eels and relatives), with the two clades together forming a sister group of Clupeocephala which includes all the remaining teleosts. The arowana genome retains the full complement of eight Hox clusters unlike the African butterfly fish (Pantodon buchholzi), another bonytongue fish, which possess only five Hox clusters. Differential gene expression among three varieties provides insights into the genetic basis of colour variation. A potential heterogametic sex chromosome is identified in the female arowana karyotype, suggesting that the sex is determined by a ZW/ZZ sex chromosomal system. The high-quality reference genome of the golden arowana and the draft assemblies of the red and green varieties are valuable resources for understanding the biology, adaptation and behaviour of Asian arowanas.

Understanding determinants of the invasiveness and ecological impacts of alien species is amongst the most sought-after and urgent research questions in ecology. Several studies have shown the value of comparing the functional responses (FRs) of alien and native predators towards native prey, however, the technique is under-explored with herbivorous alien species and as a predictor of invasiveness as distinct from ecological impact. Here, in China, we conducted a mesocosm experiment to compare the FRs among three herbivorous snail species: the golden apple snail, Pomacea canaliculata, a highly invasive and high impact alien listed in “100 of the World's Worst Invasive Alien Species”; Planorbarius corneus, a non-invasive, low impact alien; and the Chinese native snail, Bellamya aeruginosa, when feeding on four locally occurring plant species. Further, by using a numerical response equation, we modelled the population dynamics of the snail consumers. For standard FR parameters, we found that the invasive and damaging alien snail had the highest “attack rates” a, shortest “handling times” h and also the highest estimated maximum feeding rates, 1/hT, whereas the native species had the lowest attack rates, longest handling times and lowest maximum feeding rates. The non-invasive, low impact alien species had consistently intermediate FR parameters. The invasive alien species had higher population growth potential than the native snail species, whilst that of the non-invasive alien species was intermediate. Thus, while the comparative FR approach has been proposed as a reliable method for predicting the ecological impacts of invasive predators, our results further suggest that comparative FRs could extend to predict the invasiveness and ecological impacts of alien herbivores and should be explored in other taxa and trophic groups to determine the general utility of the approach.

This study investigated whether Helicobacter pylori could activate the nucleotide-binding oligomerization domain-like receptor (NLR) family, pyrin domain-containing 3 (NLRP3) inflammasome in human macrophages and the involvement of reactive oxygen species (ROS) in inflammasome activation. Phorbol-12-myristate-13-acetate (PMA)-differentiated human acute monocytic leukemia cell line THP-1 was infected with H. pylori. The levels of pro-inflammatory cytokines interleukin (IL)-1β and IL-18 in supernatant were measured by ELISA. Intracellular ROS level was analyzed by flow cytometry. Quantitative real-time PCR and western blot analysis were employed to determine the mRNA and protein expression levels of NLRP3 and caspase-1 in THP-1 cells, respectively. Our results showed that H. pylori infection could induce IL-1β and IL-18 production in PMA-differentiated THP-1 cells in a dose- and time-dependent manner. Moreover, secretion of IL-1β and IL-18 in THP-1 cells following H. pylori infection was remarkably reduced by NLRP3-specific small interfering RNA treatment. In addition, the intracellular ROS level was elevated by H. pylori infection, which could be eliminated by the ROS scavenger N-acetylcysteine (NAC). Furthermore, NAC treatment could inhibit NLRP3 inflammasome formation and caspase-1 activation and suppress the release of IL-1β and IL-18 from H. pylori-infected THP-1 cells. These findings provide novel insights into the innate immune response against H. pylori infection, which could potentially be used for the prevention and treatment of H. pylori-related diseases.

The aim of the study was to investigate the effects of dietary linseed (rich in n-3 PUFA) on expression of inflammation-related genes and on growth performance of growing-finishing barrows. Two isoenergetic and isonitrogenous diets were formulated, one as the basal diet and the other containing 10% linseed. Twenty-four Landrace x Yorkshire barrows weighing 35 +/- 3.7 kg were randomly assigned to 1 of 4 treatment groups, with 6 pigs per group. During the entire experimental period of 90 d, these 4 groups of pigs were first fed the basal diet and then fed the linseed diet for 0, 30, 60, and 90 d before slaughter, respectively. Pig growth; messenger RNA (mRNA) expression of peroxisome proliferator-activated receptor-gamma (PPARgamma), IL-1beta0, IL-6, and tumor necrosis factor-alpha (TNF-alpha); and plasma concentrations of the 3 proinflammatory cytokines were measured and analyzed. Average daily feed intake did not differ among treatment groups (P > 0.05), but ADG (P < 0.05) and G:F (P < 0.01) responded quadratically to the duration of linseed diet feeding, and pigs in the 60-d treatment group had the greatest ADG and G:F. The mRNA expression of PPARgamma in loin muscle and spleen increased linearly (P < 0.01) with the duration of linseed diet feeding, whereas its expression in adipose tissue was not affected (P = 0.095). Tumor necrosis factor-alpha and IL-6 mRNA expression in muscle, adipose, and spleen, as well as serum concentration of TNF-alpha, decreased linearly (P < 0.01) with the duration of linseed diet feeding. Peroxisome proliferator-activated receptor-gamma mRNA abundance was negatively correlated with IL-1beta, IL-6, and TNF-alpha mRNA abundance both in muscle (R(2) = 0.63, P < 0.001) and in spleen (R(2) = 0.69, P < 0.001), and PPARgamma mRNA expression in spleen (R(2) = 0.59, P < 0.01) and muscle (R(2) = 0.52, P < 0.05) was negatively correlated with serum TNF-alpha concentration. There were also significant quadratic relations between ADG and expression of PPARgamma (P < 0.05) and splenic TNF-alpha (P < 0.05). These data suggest that intake of n-3 PUFA from the linseed diet led to significant decreases in the expression of proinflammatory cytokine genes, which may stimulate growth in growing-finishing barrows, at least in part, through a PPARgamma-dependent mechanism.

One unique feature of L. pneumophila Dot/Icm effectors is the existence of protein families with members of high-level similarity. Whereas members of some families are functionally redundant, as suggested by their primary sequences, the relationship between SidJ and SdjA, the two members of the SidJ family, has remained mysterious.