Gaucher disease (Norrbottnian type III): probable founders identified by genealogical and molecular studies

Gaucher disease type III (GD) is found at a high frequency in northern Sweden. The contemporary Swedish index families are found in two geographically distinct clusters with the highest world-wide frequency of type III GD. A single T-to-C transition in exon 10 has previously been identified in patients from one of the two isolates and we report there the same mutation in the second isolate. Mutational analysis was combined with a genealogical reconstruction of 19 contemporary index families. Both clusters were traced back to two corresponding pairs of ancestors over a 9–13 generation span. Molecular studies show that the two clusters are compatible with a single founder who arrived in northern Sweden in or before the 16th century.     

Arthritis suppression by NADPH activation operates through an interferon-β pathway

Background  

A polymorphism in the activating component of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex, neutrophil cytosolic factor 1 (NCF1), has previously been identified as a regulator of arthritis severity in mice and rats. This discovery resulted in a search for NADPH oxidase-activating substances as a potential new approach to treat autoimmune disorders such as rheumatoid arthritis (RA). We have recently shown that compounds inducing NCF1-dependent oxidative burst, e.g. phytol, have a strong ameliorating effect on arthritis in rats. However, the underlying molecular mechanism is still not clearly understood. The aim of this study was to use gene-expression profiling to understand the protective effect against arthritis of activation of NADPH oxidase in the immune system.     

Concurrent biotic interactions influence plant performance at their altitudinal distribution margins

Recent studies have shown that biotic interactions can shape species' distributions, but empirical data on multiple biotic interactions are scarce. Therefore, we examined effects of plant–plant and plant–herbivore interactions on plant survival, growth and reproduction at different altitudes. For these purposes we conducted a factorial neighbor removal and large herbivore exclusion experiment with six transplant species (three tall forbs with their main distribution at low altitudes and three small forbs with their main distribution at high altitudes) on Låkta?ohkka Mountain, northern Sweden, replicated at two altitudes (ca 600 and 900 m a.s.l.) and consequently a 2.1°C difference in summer air temperatures. Overall transplant survival was 93%. Two out of three tall forbs grew better at low than at high altitudes, while no significant differences in growth between altitudes were found for any of the three small forbs. Since the main difference in abiotic conditions between the altitudes was most likely in temperature (as the sites were topographically and edaphically matched as closely as possible), this result indicates that climatic warming could induce upward migration of tall low‐altitude forbs. Negative plant–plant interactions prevailed at both altitudes, and we found indications that competition may set the lower altitudinal limits of some small tundra forbs. Thus, increased competition in response to climate warming may potentially shift the lower margins of high‐altitude forbs' distributions upward. Large mammalian grazers reduced the growth of tall forbs and enhanced the flowering of small forbs, and grazers could thus at least partly counteract the anticipated warming‐induced distribution shifts.     

Organization of nucleotide sequences in the chicken genome

The four major components of chicken DNA were prepared by density gradient centrifugation and characterized in several basic properties: relative amounts, dG + dC content, buoyant densities, compositional heterogeneity, and reassociation kinetics. While the relative amounts and the compositions of the major components of chicken DNA were similar to those found in mammalian genomes, their compositional heterogeneities were found to be narrower. The relative amounts of interspersed repeated and unique sequences were strikingly different in different components and also different from those found in the corresponding major components of mouse and human DNAs. If one takes into consideration that major DNA components (a) account for practically all of main-band DNA and (b) derive by preparative breakage from very long DNA segments of fairly homogeneous composition, the isochores, our findings indicate that the distribution of interspersed repeats is different in different chromosomal regions and is species-specific.