Loci on 20q13 and 21q22 are associated with pediatric-onset inflammatory bowel disease

Inflammatory bowel disease (IBD) is a common inflammatory disorder with complex etiology that involves both genetic and environmental triggers, including but not limited to defects in bacterial clearance, defective mucosal barrier and persistent dysregulation of the immune response to commensal intestinal bacteria. IBD is characterized by two distinct phenotypes: Crohn's disease (CD) and ulcerative colitis (UC). Previously reported GWA studies have identified genetic variation accounting for a small portion of the overall genetic susceptibility to CD and an even smaller contribution to UC pathogenesis. We hypothesized that stratification of IBD by age of onset might identify additional genes associated with IBD. To that end, we carried out a GWA analysis in a cohort of 1,011 individuals with pediatric-onset IBD and 4,250 matched controls. We identified and replicated significantly associated, previously unreported loci on chromosomes 20q13 (rs2315008[T] and rs4809330[A]; P = 6.30 x 10(-8) and 6.95 x 10(-8), respectively; odds ratio (OR) = 0.74 for both) and 21q22 (rs2836878[A]; P = 6.01 x 10(-8); OR = 0.73), located close to the TNFRSF6B and PSMG1 genes, respectively.     

Common sequence variants on 20q11.22 confer melanoma susceptibility

We conducted a genome-wide association pooling study for cutaneous melanoma and performed validation in samples totaling 2,019 cases and 2,105 controls. Using pooling, we identified a new melanoma risk locus on chromosome 20 (rs910873 and rs1885120), with replication in two further samples (combined P < 1 x 10(-15)). The per allele odds ratio was 1.75 (1.53, 2.01), with evidence for stronger association in early-onset cases.     

Newly identified loci that influence lipid concentrations and risk of coronary artery disease

To identify genetic variants influencing plasma lipid concentrations, we first used genotype imputation and meta-analysis to combine three genome-wide scans totaling 8,816 individuals and comprising 6,068 individuals specific to our study (1,874 individuals from the FUSION study of type 2 diabetes and 4,184 individuals from the SardiNIA study of aging-associated variables) and 2,758 individuals from the Diabetes Genetics Initiative, reported in a companion study in this issue. We subsequently examined promising signals in 11,569 additional individuals. Overall, we identify strongly associated variants in eleven loci previously implicated in lipid metabolism (ABCA1, the APOA5-APOA4-APOC3-APOA1 and APOE-APOC clusters, APOB, CETP, GCKR, LDLR, LPL, LIPC, LIPG and PCSK9) and also in several newly identified loci (near MVK-MMAB and GALNT2, with variants primarily associated with high-density lipoprotein (HDL) cholesterol; near SORT1, with variants primarily associated with low-density lipoprotein (LDL) cholesterol; near TRIB1, MLXIPL and ANGPTL3, with variants primarily associated with triglycerides; and a locus encompassing several genes near NCAN, with variants strongly associated with both triglycerides and LDL cholesterol). Notably, the 11 independent variants associated with increased LDL cholesterol concentrations in our study also showed increased frequency in a sample of coronary artery disease cases versus controls.     

'Lophenteropneust' hypothesis refuted by collection and photos of new deep-sea hemichordates

The deep ocean is home to a group of broad-collared hemichordates--the so-called 'lophenteropneusts'--that have been photographed gliding on the sea floor but have not previously been collected. It has been claimed that these worms have collar tentacles and blend morphological features of the two main hemichordate body plans, namely the tentacle-less enteropneusts and the tentacle-bearing pterobranchs. Consequently, lophenteropneusts have been invoked as missing links to suggest that the former evolved into the latter. The most significant aspect of the lophenteropneust hypothesis is its prediction that the fundamental body plan within a basal phylum of deuterostomes was enteropneust-like. The assumption of such an ancestral state influences ideas about the evolution of the vertebrates from the invertebrates. Here we report on the first collected specimen of a broad-collared, deep-sea enteropneust and describe it as a new family, genus and species. The collar, although disproportionately broad, lacks tentacles. In addition, we find no evidence of tentacles in the available deep-sea photographs (published and unpublished) of broad-collared enteropneusts, including those formerly designated as lophenteropneusts. Thus, the lophenteropneust hypothesis was based on misinterpretation of deep-sea photographs of low quality and should no longer be used to support the idea that the enteropneust body plan is basal within the phylum Hemichordata.     

An integrated view of the chemistry and mineralogy of martian soils

The mineralogical and elemental compositions of the martian soil are indicators of chemical and physical weathering processes. Using data from the Mars Exploration Rovers, we show that bright dust deposits on opposite sides of the planet are part of a global unit and not dominated by the composition of local rocks. Dark soil deposits at both sites have similar basaltic mineralogies, and could reflect either a global component or the general similarity in the compositions of the rocks from which they were derived. Increased levels of bromine are consistent with mobilization of soluble salts by thin films of liquid water, but the presence of olivine in analysed soil samples indicates that the extent of aqueous alteration of soils has been limited. Nickel abundances are enhanced at the immediate surface and indicate that the upper few millimetres of soil could contain up to one per cent meteoritic material.     

Water alteration of rocks and soils on Mars at the Spirit rover site in Gusev crater

Gusev crater was selected as the landing site for the Spirit rover because of the possibility that it once held a lake. Thus one of the rover's tasks was to search for evidence of lake sediments. However, the plains at the landing site were found to be covered by a regolith composed of olivine-rich basaltic rock and windblown 'global' dust. The analyses of three rock interiors exposed by the rock abrasion tool showed that they are similar to one another, consistent with having originated from a common lava flow. Here we report the investigation of soils, rock coatings and rock interiors by the Spirit rover from sol (martian day) 1 to sol 156, from its landing site to the base of the Columbia hills. The physical and chemical characteristics of the materials analysed provide evidence for limited but unequivocal interaction between water and the volcanic rocks of the Gusev plains. This evidence includes the softness of rock interiors that contain anomalously high concentrations of sulphur, chlorine and bromine relative to terrestrial basalts and martian meteorites; sulphur, chlorine and ferric iron enrichments in multilayer coatings on the light-toned rock Mazatzal; high bromine concentration in filled vugs and veins within the plains basalts; positive correlations between magnesium, sulphur and other salt components in trench soils; and decoupling of sulphur, chlorine and bromine concentrations in trench soils compared to Gusev surface soils, indicating chemical mobility and separation.     

人类基因组序列图并非完美

在被问及人类基因组最新的一张碱基序列图时,冰岛科学家们认为其中有大约100个片段需要认真修改。 凯撒西部保留地大学(Case Western Reserve)的