Chalone-like inhibition of DNA synthesis in helminths

Chalone-like inhibitory activity was found in extracts from tissues of Taenia crassiceps cysticercus and tissues of adult Ascaris suum. The inhibitory effects were partially species nonspecific: The extracts from T. crassiceps larvae inhibit both T. crassiceps and Mesocestoides corti larvae DNA synthesis. Extracts from A. suum, however, inhibit only T. crassiceps. Besides them, the inhibitory factor from mouse brain inhibits both T. crassiceps and M. corti DNA synthesis. When the inhibitory factor from A. suum was applied 4 times during 24-hr culture (at 6-hr intervals), the inhibitory effect was decreased.     

LysM-type mycorrhizal receptor recruited for rhizobium symbiosis in nonlegume Parasponia

Rhizobium-root nodule symbiosis is generally considered to be unique for legumes. However, there is one exception, and that is Parasponia. In this nonlegume, the rhizobial nodule symbiosis evolved independently and is, as in legumes, induced by rhizobium Nod factors. We used Parasponia andersonii to identify genetic constraints underlying evolution of Nod factor signaling. Part of the signaling cascade, downstream of Nod factor perception, has been recruited from the more-ancient arbuscular endomycorrhizal symbiosis. However, legume Nod factor receptors that activate this common signaling pathway are not essential for arbuscular endomycorrhizae. Here, we show that in Parasponia a single Nod factor-like receptor is indispensable for both symbiotic interactions. Therefore, we conclude that the Nod factor perception mechanism also is recruited from the widespread endomycorrhizal symbiosis.     

Genotyping by sequencing of rice interspecific backcross inbred lines identifies QTLs for grain weight and grain length

Grain weight and grain length are the most stable components of rice yield and important indicators of consumer preference. Considering the potentials of wild rice and to enhance the rice yields to meet the increasing demands, 185 Backcross Inbred Lines (BILs) in the background of O. sativa ssp. indica cv. PR114, including 63 rufi-BILs derived from O. rufipogon IRGC104433 and 122 glumae-BILs from O. glumaepatula IRGC104387 were evaluated for mapping QTLs for yield and yield component traits using Genotyping by Sequencing (GBS). Phenotypic evaluation of BILs in three seasons spanning two locations revealed significant differences compared with recurrent parent. BILs which did not show significant differences for any trait under investigation, or similar based on pedigree, were excluded from GBS. Some glumae-BILs had to be excluded from mapping QTLs due to less sequence information. A custom designed approach for GBS data analysis identified 3322 informative SNPs in 55 rufi-BILs and 3437 informative SNPs in 79 glumae-BILs. QTL mapping identified one QTL for thousand grain weight (qtgw5.1), two for grain width (qgw5.1, qgw5.2) and one for grain length (qgl7.1) in rufi-BILs. In the glumae-BILs, three QTL for thousand grain weight (qtgw2.1, qtgw3.1, qtgw6.1) and two for grain length (qgl3.1, qgl7.1) were identified. Most of the grain weight and width QTL showed positive additive effect contributed by wild species allele, whereas the grain length QTL showed positive additive effect contributed by recurrent parent allele. Based on their physical position, none of the QTLs were found similar to previously cloned QTLs. QTLs for grain traits identified from low yielding wild relatives of rice reveals their significance in improving further the rice yields and widen the genetic base of cultivated rice.     

De Novo Next Generation Sequencing of Plant Genomes

The genome sequencing of all major food and bioenergy crops is of critical importance in the race to improve crop production to meet the future food and energy security needs of the world. Next generation sequencing technologies have brought about great improvements in sequencing throughput and cost, but do not yet allow for de novo sequencing of large repetitive genomes as found in most crop plants. We present a strategy that combines cutting edge next generation sequencing with “old school” genomics resources and allows rapid cost-effective sequencing of plant genomes.     

Immunologic memory responses induced in BALB/c mice by cross-linked outer membrane extracts of four Salmonella serotypes

Outer membrane proteins (OMP), extracted from Salmonella enteritidis, S anatum, S typhimurium, and S infantis, were cross-linked to form a large immunogen (4-OMP-lipopolysaccharide [LPS]). Vaccinations with 4-OMP-LPS dissolved in phosphate-buffered saline solution and 4-OMP-LPS emulsified with muramyl dipeptide were capable of eliciting specific and sustained primary IgM and IgG responses in BALB/c mice, as well as inducing immunologic memory for 130 days. In addition to 4-OMP-LPS-specific responses, substantial IgM and IgG responses specific for each live homologous organism were detected over the 130-day trial. In comparison with vaccination with 4-OMP-LPS dissolved in phosphate-buffered saline solution, responses specific for the antigen or the homologous Salmonella were not markedly increased in mice vaccinated with 4-OMP-LPS emulsified with muramyl dipeptide. Seemingly, cross-linked OMP, without the inclusion of muramyl dipeptide, may have potential as vaccine components and may induce immunologic memory.     

Climate change and translocations: The potential to re-establish two regionally-extinct butterfly species in Britain

Climate change is causing many organisms to migrate to track climatically-suitable habitat. In many cases, this will happen naturally, but in others, human intervention may be necessary in the form of ‘assisted colonisation’. Species re-establishments in suitable parts of their historic ranges provide an opportunity to conserve some species and to test ideas about assisted colonisation. Here, bioclimatic models of the distributions of two extinct British butterflies, Aporia crataegi and Polyommatus semiargus, were used to investigate the potential for re-establishment in Britain. Generalised additive models and generalised linear models were created to describe the species’ European distributions for the period 1961–1990. All models projected the British climate during this period to be suitable for both species. Thirty-year climate projections for the periods 1991–2020 and 2021–2050, and for three climate change scenarios, were then put into the models to generate projections of climatic suitability throughout the 21st century. British climate was projected to remain highly suitable for A. crataegi, but to decline somewhat for P. semiargus. Southern and eastern Britain were found to be the areas most likely to support suitable climate. This difference between the species appeared to be due in part to decreasing summer rainfall in climate change projections, as this should only benefit A. crataegi. It is concluded that, with further study of habitat requirements, both species could be reintroduced to Britain as part of a long-term European conservation strategy.