Wnk4 controls blood pressure and potassium homeostasis via regulation of mass and activity of the distal convoluted tubule

The mechanisms that govern homeostasis of complex systems have been elusive but can be illuminated by mutations that disrupt system behavior. Mutations in the gene encoding the kinase WNK4 cause pseudohypoaldosteronism type II (PHAII), a syndrome featuring hypertension and hyperkalemia. We show that physiology in mice transgenic for genomic segments harboring wild-type (TgWnk4(WT)) or PHAII mutant (TgWnk4(PHAII)) Wnk4 is changed in opposite directions: TgWnk4(PHAII) mice have higher blood pressure, hyperkalemia, hypercalciuria and marked hyperplasia of the distal convoluted tubule (DCT), whereas the opposite is true in TgWnk4(WT) mice. Genetic deficiency for the Na-Cl cotransporter of the DCT (NCC) reverses phenotypes seen in TgWnk4(PHAII) mice, demonstrating that the effects of the PHAII mutation are due to altered NCC activity. These findings establish that Wnk4 is a molecular switch that regulates the balance between NaCl reabsorption and K+ secretion by altering the mass and function of the DCT through its effect on NCC.     

Clonal evolution in relapsed acute myeloid leukaemia revealed by whole-genome sequencing

Most patients with acute myeloid leukaemia (AML) die from progressive disease after relapse, which is associated with clonal evolution at the cytogenetic level. To determine the mutational spectrum associated with relapse, we sequenced the primary tumour and relapse genomes from eight AML patients, and validated hundreds of somatic mutations using deep sequencing; this allowed us to define clonality and clonal evolution patterns precisely at relapse. In addition to discovering novel, recurrently mutated genes (for example, WAC, SMC3, DIS3, DDX41 and DAXX) in AML, we also found two major clonal evolution patterns during AML relapse: (1) the founding clone in the primary tumour gained mutations and evolved into the relapse clone, or (2) a subclone of the founding clone survived initial therapy, gained additional mutations and expanded at relapse. In all cases, chemotherapy failed to eradicate the founding clone. The comparison of relapse-specific versus primary tumour mutations in all eight cases revealed an increase in transversions, probably due to DNA damage caused by cytotoxic chemotherapy. These data demonstrate that AML relapse is associated with the addition of new mutations and clonal evolution, which is shaped, in part, by the chemotherapy that the patients receive to establish and maintain remissions.     

Disturbance of lekking Lesser Prairie-Chickens ( Tympanuchus pallidicinctus ) by Ring-necked Pheasants ( Phasianus colchicus )

Lesser Prairie-Chicken ( Tympanuchus pallidicinctus ) populations have experienced dramatic rangewide declines (up to 92%) since settlement of the Great Plains. This decline has been attributed to changes in land-use practices, such as conversion of native rangelands to intensive agriculture and increased grazing pressure. These changes may increase the impact of interspecific competition on populations. We documented disturbance of lekking Lesser Prairie-Chickens by Ring-necked Pheasants ( Phasianus colchicus ). Future management and research should take into account possible impacts to Lesser Prairie-Chickens during the breeding season.     

Captures of Crawford's gray shrews ( Notiosorex crawfordi ) along the Rio Grande in central New Mexico

We captured >2000 Crawford’s gray shrews ( Notiosorex crawfordi ) in a riparian forest mainly consisting of cottonwoods ( Populus deltoides ) along the Rio Grande in central New Mexico. Little has been published about abundance and habitat of Crawford’s gray shrew throughout its distributional range. During 7 summers, we captured shrews in pitfall traps at 13 study sites in Bernalillo, Valencia, and Socorro counties. Capture rates of shrews were greatest in August and September, and we did not detect a response of shrews to restoration treatments that removed nonnative plants from riparian forests. Results from our study indicate that (1) Crawford’s gray shrews are more abundant in riparian habitats than historically presumed and (2) pitfall traps with drift fences are an effective means to capture shrews.     

Cell surface antigen profiling using a novel type of antibody array immobilised to plasma ion-implanted polycarbonate

To identify and sort out subpopulations of cells from more complex and heterogeneous assemblies of cells is important for many biomedical applications, and the development of cost- and labour-efficient techniques to accomplish this is warranted. In this report, we have developed a novel array-based platform to discriminate cellular populations based on differences in cell surface antigen expressions. These cell capture microarrays were produced through covalent immobilisation of CD antibodies to plasma ion immersion implantation-treated polycarbonate (PIII-PC), which offers the advantage of a transparent matrix, allowing direct light microscopy visualisation of captured cells. The functionality of the PIII-PC array was validated using several cell types, resulting in unique surface antigen expression profiles. PIII-PC results were compatible with flow cytometry, nitrocellulose cell capture arrays and immunofluorescent staining, indicating that the technique is robust. We report on the use of this PIII-PC cluster of differentiation (CD) antibody array to gain new insights into neural differentiation of mouse embryonic stem (ES) cells and into the consequences of genetic targeting of the Notch signalling pathway, a key signalling mechanism for most cellular differentiation processes. Specifically, we identify CD98 as a novel marker for neural precursors and polarised expression of CD9 in the apical domain of ES cell-derived neural rosettes. We further identify expression of CD9 in hitherto uncharacterised non-neural cells and enrichment of CD49e- and CD117-positive cells in Notch signalling-deficient ES cell differentiations. In conclusion, this work demonstrates that covalent immobilisation of antibody arrays to the PIII-PC surface provides faithful cell surface antigen data in a cost- and labour-efficient manner. This may be used to facilitate high throughput identification and standardisation of more precise marker profiles during stem cell differentiation and in various genetic and disease contexts.     

Mapping and sequencing of structural variation from eight human genomes

Genetic variation among individual humans occurs on many different scales, ranging from gross alterations in the human karyotype to single nucleotide changes. Here we explore variation on an intermediate scale--particularly insertions, deletions and inversions affecting from a few thousand to a few million base pairs. We employed a clone-based method to interrogate this intermediate structural variation in eight individuals of diverse geographic ancestry. Our analysis provides a comprehensive overview of the normal pattern of structural variation present in these genomes, refining the location of 1,695 structural variants. We find that 50% were seen in more than one individual and that nearly half lay outside regions of the genome previously described as structurally variant. We discover 525 new insertion sequences that are not present in the human reference genome and show that many of these are variable in copy number between individuals. Complete sequencing of 261 structural variants reveals considerable locus complexity and provides insights into the different mutational processes that have shaped the human genome. These data provide the first high-resolution sequence map of human structural variation--a standard for genotyping platforms and a prelude to future individual genome sequencing projects.     

A map of the day-night contrast of the extrasolar planet HD 189733b

'Hot Jupiter' extrasolar planets are expected to be tidally locked because they are close (<0.05 astronomical units, where 1 au is the average Sun-Earth distance) to their parent stars, resulting in permanent daysides and nightsides. By observing systems where the planet and star periodically eclipse each other, several groups have been able to estimate the temperatures of the daysides of these planets. A key question is whether the atmosphere is able to transport the energy incident upon the dayside to the nightside, which will determine the temperature at different points on the planet's surface. Here we report observations of HD 189733, the closest of these eclipsing planetary systems, over half an orbital period, from which we can construct a 'map' of the distribution of temperatures. We detected the increase in brightness as the dayside of the planet rotated into view. We estimate a minimum brightness temperature of 973 +/- 33 K and a maximum brightness temperature of 1,212 +/- 11 K at a wavelength of 8 mum, indicating that energy from the irradiated dayside is efficiently redistributed throughout the atmosphere, in contrast to a recent claim for another hot Jupiter. Our data indicate that the peak hemisphere-integrated brightness occurs 16 +/- 6 degrees before opposition, corresponding to a hotspot shifted east of the substellar point. The secondary eclipse (when the planet moves behind the star) occurs 120 +/- 24 s later than predicted, which may indicate a slightly eccentric orbit.     

Genome-wide association and large-scale follow up identifies 16 new loci influencing lung function

Pulmonary function measures reflect respiratory health and are used in the diagnosis of chronic obstructive pulmonary disease. We tested genome-wide association with forced expiratory volume in 1 second and the ratio of forced expiratory volume in 1 second to forced vital capacity in 48,201 individuals of European ancestry with follow up of the top associations in up to an additional 46,411 individuals. We identified new regions showing association (combined P < 5 × 10(-8)) with pulmonary function in or near MFAP2, TGFB2, HDAC4, RARB, MECOM (also known as EVI1), SPATA9, ARMC2, NCR3, ZKSCAN3, CDC123, C10orf11, LRP1, CCDC38, MMP15, CFDP1 and KCNE2. Identification of these 16 new loci may provide insight into the molecular mechanisms regulating pulmonary function and into molecular targets for future therapy to alleviate reduced lung function.