One plus one is greater than two: mixing litter types accelerates decomposition of low-quality alpine dwarf shrub litter

Plant and Soil - A reliable root architectural model is required to study tree anchorage, including secondary root growth, from seed to the mature stage. We calibrated the generic RootTyp model for...     

When one plus one equals three: Biochemistry and bioinformatics combine to answer complex questions

The availability of whole genome assemblies from evolutionarily distant species and iterative search algorithms has boosted ortholog analyses. However, orthology per se is not a sufficient predictor of a specific function. In a recent study, we have combined bioinformatic analysis and biochemistry to study the evolution of the multi-component SMN (Survival Motor Neuron)-complex. This macromolecular machinery performs essential steps during the assembly of spliceosomal UsnRNPs. By orthology, many factors constituting the SMN-complex in humans developed early in evolution. Some were secondarily lost in Drosophila. Compositional investigation of the Drosophila SMN-complex by biochemistry revealed the absence of two predicted orthologs although the complex was functional. Their bioinformatical re-assessment showed rapid sequence divergence indicating loss of evolutionary pressure in Drosophila. As a tool to better understand the function of individual proteins in multimeric molecular machineries, we therefore advocate iterative combination of bioinformatics with biochemical or functional assessment.     

ER export: more than one way out

Protein export from the ER is mediated by COPII vesicles. Glycosylphosphatidylinositol-linked proteins seem to be segregated from other cargo proteins during ER export, suggesting that ER membranes produce more than one type of vesicle.     

MPN tables for more than one test

Summary MPN tables are presented, restricted to those tube combinations that are acceptable considering the number of tests performed (1, 2, 3, 5, or 10). Confidence limits of 95 and 99% are given for each result.     

When two is better than one

Gene duplication and divergence has long been considered an important route to adaptation and phenotypic evolution. Reporting in Nature, Hittinger and Carroll (2007) provide the first clear example of adaptations in both regulatory regions and protein-coding regions after gene duplication. This combination of evolutionary changes appears to have resolved an adaptive conflict, leading to increased organismal fitness.     

Left-right asymmetry: more than one way to coil a shell

Snail shells can be left-handed or right-handed, sometimes within one species. For over a century, it has commonly been assumed that mirror-image shell coiling in snails is correlated with a mirror- image reversal of early spindle orientation and cleavage. The results of an exciting and elegant new study refute this model, showing that right doesn't have to be the mirror image of left.     

Building flax fibres: more than one brick in the walls

The objective of the review is to provide fundamental knowledge on the chemical composition and structural characteristics of flax fibres. These are long and multinucleate cells without septum or partition (average length 2–5 cm) and have a secondary wall of very large thickness (5–15 μm). Fibres are gathered in bundles of one to three dozen cells that encircle the vascular cylinder. The bundle cohesion is insured by pectins, accumulating in the primary wall and cell junctions. In contrast, lignin, which is present in very low amount, does not seem to play a major role in bundle cohesion. At maturity, secondary wall is characterised by (i) a high level of cellulose with microfibrils locked into an almost axial direction and (ii) 5–15% non-cellulosic polysaccharides (NCPs). The chemical composition of NCPs depends on growth stage, indicating important cell wall remodelling, fibre position and variety. Despite the large disparity of the results reported in the literature, galactose appears to be the predominant sugar of NCPs, and β-1-4-galactan together with rhamnogalacturonan of type I (RG-I) and polygalacturonic acid (PGA) become, with fibre maturity, the most abundant tightly bound NCPs. Glycine-rich proteins (GRPs) and arabinogalactan-proteins (AGPs), also present in flax fibres, are both characterised by appreciable levels of glycine and acidic amino acid and are deficient in hydroxyproline, and may contribute to the cross-linking of pectins. (Galacto)glucomanans/glucans rather than xylans consist of cross-linking polymers in fibre secondary wall. A model is proposed where cellulose microfibrils, tethered by cross-linking (galacto)glucomanans/glucans, are embedded in a pectic matrix.     

A20: more than one way to skin a cat

In this issue of Molecular Cell, Skaug et al. (2011) propose a polyubiquitin-dependent, noncatalytic mechanism by which the deubiquitinase A20 inhibits IκB kinase and NF-κB activation.     

Bird communication: two voices are better than one

How do emperor penguins find their mates on a featureless ice flow, packed at densities of ten animals per square meter? A recent study has revealed how use of their 'two-voice' calls enables emperor penguins to locate their mates and chicks under some of nature's most extreme conditions.     

Protein transport: two translocons are better than one

The translocon is the gateway to the endoplasmic reticulum (ER). In yeast this is the Sec61p complex. However, new evidence suggests that a second translocon containing the Sec61p homolog Ssh1p provides important flexibility to the ER translocation machinery.