A molecular phylogeny of marine amphipods in the herbivorous family Ampithoidae

Ampithoid amphipods dominate invertebrate assemblages associated with shallow‐water macroalgae and seagrasses worldwide and represent the most species‐rich family of herbivorous amphipod known. To generate the first molecular phylogeny of this family, we sequenced 35 species from 10 genera at two mitochondrial genes [the cytochrome c oxidase subunit I (COI) and the large subunit of 16 s (LSU)] and two nuclear loci [sodium–potassium ATPase (NAK) and elongation factor 1‐alpha (EF1)], for a total of 1453 base pairs. All 10 genera are embedded within an apparently monophyletic Ampithoidae (Amphitholina, Ampithoe, Biancolina, Cymadusa, Exampithoe, Paragrubia, Peramphithoe, Pleonexes, Plumithoe, Pseudoamphithoides and Sunamphitoe). Biancolina was previously placed within its own superfamily in another suborder. Within the family, single‐locus trees were generally poor at resolving relationships among genera. Combined‐locus trees were better at resolving deeper nodes, but complete resolution will require greater taxon sampling of ampithoids and closely related outgroup species, and more molecular characters. Despite these difficulties, our data generally support the monophyly of Ampithoidae, novel evolutionary relationships among genera, several currently accepted genera that will require revisions via alpha taxonomy and the presence of cryptic species.     

Synthesis of L‐Lys‐Aminoxy‐Goralatide

Natural tetrapeptide Goralatide inhibits primitive hematopoietic cell proliferation but reported to be rather unstable in solution (half‐life 4.5 min). In this work, we report the synthesis of an aminoxy analog of Goralatide. Aminoxy moiety is expected to provide increased stability and bioavailability of the Goralatide analog. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.     

Mutation analysis in Bardet�CBiedl syndrome by DNA pooling and massively parallel resequencing in 105 individuals

Bardet-Biedl syndrome (BBS) is a rare, primarily autosomal-recessive ciliopathy. The phenotype of this pleiotropic disease includes retinitis pigmentosa, postaxial polydactyly, truncal obesity, learning disabilities, hypogonadism and renal anomalies, among others. To date, mutations in 15 genes (BBS1-BBS14, SDCCAG8) have been described to cause BBS. The broad genetic locus heterogeneity renders mutation screening time-consuming and expensive. We applied a strategy of DNA pooling and subsequent massively parallel resequencing (MPR) to screen individuals affected with BBS from 105 families for mutations in 12 known BBS genes. DNA was pooled in 5 pools of 21 individuals each. All 132 coding exons of BBS1-BBS12 were amplified by conventional PCR. Subsequent MPR was performed on an Illumina Genome Analyzer II? platform. Following mutation identification, the mutation carrier was assigned by CEL I endonuclease heteroduplex screening and confirmed by Sanger sequencing. In 29 out of 105 individuals (28%), both mutated alleles were identified in 10 different BBS genes. A total of 35 different disease-causing mutations were confirmed, of which 18 mutations were novel. In 12 additional families, a total of 12 different single heterozygous changes of uncertain pathogenicity were found. Thus, DNA pooling combined with MPR offers a valuable strategy for mutation analysis of large patient cohorts, especially in genetically heterogeneous diseases such as BBS.     

Limnological regime shifts caused by climate warming and Lesser Snow Goose population expansion in the western Hudson Bay Lowlands (Manitoba,Canada)

Shallow lakes are dominant features in subarctic and Arctic landscapes and are responsive to multiple stressors, which can lead to rapid changes in limnological regimes with consequences for aquatic resources. We address this theme in the coastal tundra region of Wapusk National Park, western Hudson Bay Lowlands (Canada), where climate has warmed during the past century and the Lesser Snow Goose (LSG; Chen caerulescens caerulescens) population has grown rapidly during the past ~40 years. Integration of limnological and paleolimnological analyses documents profound responses of productivity, nutrient cycling, and aquatic habitat to warming at three ponds (“WAP 12”, “WAP 20”, and “WAP 21″), and to LSG disturbance at the two ponds located in an active nesting area (WAP 20, WAP 21). Based on multiparameter analysis of ²¹⁰Pb‐dated sediment records from all three ponds, a regime shift occurred between 1875 and 1900 CE marked by a transition from low productivity, turbid, and nutrient‐poor conditions of the Little Ice Age to conditions of higher productivity, lower nitrogen availability, and the development of benthic biofilm habitat as a result of climate warming. Beginning in the mid‐1970s, sediment records from WAP 20 and WAP 21 reveal a second regime shift characterized by accelerated productivity and increased nitrogen availability. Coupled with 3 years of limnological data, results suggest that increased productivity at WAP 20 and WAP 21 led to atmospheric CO₂ invasion to meet algal photosynthetic demand. This limnological regime shift is attributed to an increase in the supply of catchment‐derived nutrients from the arrival of LSG and their subsequent disturbance to the landscape. Collectively, findings discriminate the consequences of warming and LSG disturbance on tundra ponds from which we identify a suite of sensitive limnological and paleolimnological measures that can be utilized to inform aquatic ecosystem monitoring.     

Dissimilar responses of fungal and bacterial communities to soil transplantation simulating abrupt climate changes

Both fungi and bacteria play essential roles in regulating soil carbon cycling. To predict future carbon stability, it is imperative to understand their responses to environmental changes, which is subject to large uncertainty. As current global warming is causing range shifts toward higher latitudes, we conducted three reciprocal soil transplantation experiments over large transects in 2005 to simulate abrupt climate changes. Six years after soil transplantation, fungal biomass of transplanted soils showed a general pattern of changes from donor sites to destination, which were more obvious in bare fallow soils than in maize cropped soils. Strikingly, fungal community compositions were clustered by sites, demonstrating that fungi of transplanted soils acclimatized to the destination environment. Several fungal taxa displayed sharp changes in relative abundance, including Podospora, Chaetomium, Mortierella and Phialemonium. In contrast, bacterial communities remained largely unchanged. Consistent with the important role of fungi in affecting soil carbon cycling, 8.1%–10.0% of fungal genes encoding carbon‐decomposing enzymes were significantly (p < 0.01) increased as compared with those from bacteria (5.7%–8.4%). To explain these observations, we found that fungal occupancy across samples was mainly determined by annual average air temperature and rainfall, whereas bacterial occupancy was more closely related to soil conditions, which remained stable 6 years after soil transplantation. Together, these results demonstrate dissimilar response patterns and resource partitioning between fungi and bacteria, which may have considerable consequences for ecosystem‐scale carbon cycling.     

Leaf litter identity alters the timing of lotic nutrient dynamics

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