No evidence for substantial aerobic methane emission by terrestrial plants: a 13C-labelling approach

* The results of a single publication stating that terrestrial plants emit methane has sparked a discussion in several scientific journals, but an independent test has not yet been performed. * Here it is shown, with the use of the stable isotope (13)C and a laser-based measuring technique, that there is no evidence for substantial aerobic methane emission by terrestrial plants, maximally 0.3% (0.4 ng g(-1) h(-1)) of the previously published values. * Data presented here indicate that the contribution of terrestrial plants to global methane emission is very small at best. * Therefore, a revision of carbon sequestration accounting practices based on the earlier reported contribution of methane from terrestrial vegetation is redundant.     

Active specific immunotherapy with Newcastle-diseasevirus-modified autologous tumor cells following resection of liver metastases in colorectal cancer

Summary A group of 23 colorectal cancer patients were treated by a new type of active specific immunotherapy (ASI) following complete surgical resection of liver metastases (R0 resection). For ASI treatment we used a vaccine consisting of 1 × 10⁷ autologous, irradiated (200 Gy) metastases-derived tumor cells incubated with 32 hemagglutination units (HU) of Newcastle disease virus (NDV). The adjuvant vaccine therapy was started 2 weeks after surgery and was repeated five times at 14-days intervals followed by one boost 3 months later. The delayed-type hypersensitivity (DTH) skin reactions to the vaccine were measured as well as the DTH reactions to a challenge test of 1 × 10⁷ non-virus-modified autologous tumor cells from liver metastases or 1 × 10⁷ autologous normal liver cells. In addition 32 HU NDV alone and a standard antigen test (Merieux test) were applied pre- and post-vaccination. The vaccination was well tolerated. In 13 of 23 patients an increasing reactivity against the vaccine was observed during the vaccination procedure. Nine patients (40%) experienced an increased DTH reactivity against autologous tumor cells following vaccination, while 17% or fewer showed an increased reactivity to Merieux test antigens, NDV, or normal liver cells. The increased antitumor response was not correlated to responsiveness to NDV alone, autologous liver cells, enzymes and culture medium used for vaccine preparation or standard antigens (Merieux test). After a follow-up of at least 18 months 61% of the vaccinated patients developed tumor recurrence in comparison to 87% of a matched control groups from the same institution that had been only surgically treated. The results of this phase II trial are encouraging and should stimulate further prospective randomized studies.     

Growth responses to ozone in plant species from wetlands

Ten wet grassland species were fumigated with four concentrations of ozone (charcoal-filtered air, non-filtered air and non-filtered air plus 25 or 50 nl l(-1) ozone) in open-top chambers during one growing season to investigate the long-term effect of this air pollutant on various growth variables. Only Eupatorium cannabinum showed ozone-related foliar injury, while five species reacted with significantly ozone-enhanced senescence. Premature senescence was paralleled by a significant ozone-induced reduction of green leaf area in Achillea ptarmica, E. cannabinum and Plantago lanceolata. At the intermediate harvest performed after 28 days shoot weights were significantly decreased by ozone in A. ptarmica and increased in Molinia caerulea. At the final harvest performed at the end of the growing season two other species, Cirsium dissectum and E. cannabinum had a significantly reduced shoot weight due to ozone. Root biomass was determined only at the intermediate harvest. The root:shoot ratio (RSR) was significantly reduced in C. dissectum, while it increased in M. caerulea. Seven of the species developed flowers during the experiment. While no significant ozone effects on flowering date and flower numbers were detected, flower weights were significantly reduced in E. cannabinum and P. lanceolata.     

Distribution patterns of the ΔF508 mutation in the CFTR gene on CF-linked marker haplotypes in the German population

Summary We have measured the frequency of the ΔF508 mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene and its association with cystic fibrosis (CF)-linked marker haplotypes in the German population. Based on the analysis of 400 CF chromosomes, the frequency of the ΔF508 mutation is estimated to be 77.3%, the vast majority being associated with marker haplotype KM19-XV2c 2 1. Our data further suggest the presence of another frequent CF mutation associated with this marker haplotype.     

IVT-seq reveals extreme bias in RNA sequencing

Mapping-by-sequencing has emerged as a powerful technique for genetic mapping in several plant and animal species. As this resequencing-based method requires a reference genome, its application to complex plant genomes with incomplete and fragmented sequence resources remains challenging. We perform exome sequencing of phenotypic bulks of a mapping population of barley segregating for a mutant phenotype that increases the rate of leaf initiation. Read depth analysis identifies a candidate gene, which is confirmed by the analysis of independent mutant alleles. Our method illustrates how the genomic resources of barley together with exome resequencing can underpin mapping-by-sequencing.     

microRNAs associated with the different human Argonaute proteins

MicroRNAs (miRNAs) are small noncoding RNAs that function in literally all cellular processes. miRNAs interact with Argonaute (Ago) proteins and guide them to specific target sites located in the 3′-untranslated region (3′-UTR) of target mRNAs leading to translational repression and deadenylation-induced mRNA degradation. Most miRNAs are processed from hairpin-structured precursors by the consecutive action of the RNase III enzymes Drosha and Dicer. However, processing of miR-451 is Dicer independent and cleavage is mediated by the endonuclease Ago2. Here we have characterized miR-451 sequence and structure requirements for processing as well as sorting of miRNAs into different Ago proteins. Pre-miR-451 appears to be optimized for Ago2 cleavage and changes result in reduced processing. In addition, we show that the mature miR-451 only associates with Ago2 suggesting that mature miRNAs are not exchanged between different members of the Ago protein family. Based on cloning and deep sequencing of endogenous miRNAs associated with Ago1–3, we do not find evidence for miRNA sorting in human cells. However, Ago identity appears to influence the length of some miRNAs, while others remain unaffected.