KIBRA (WWC1) Is a Metastasis Suppressor Gene Affected by Chromosome 5q Loss in Triple-Negative Breast Cancer

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Existing ecological theory applies to urban environments

There is a prominent view within urban ecology that existing ecological theory is insufficient to understand the ecology of urban environments. However, many ecological theories, hypotheses and paradigms have been shown to apply to cities just as they do to other types of ecosystems. Here, I identify 16 ecological theories that have been applied to urban environments, with examples. I also illustrate the utility of metapopulation theory in cities with a case study on pond-breeding frogs in Melbourne, Australia.     

Viola pluviae sp. nov. (Violaceae), a member of subsect. Stolonosae in the Pacific Northwest region of North America

As hirtherto circumscribed, the allo‐octoploid Viola palustris L. exists in three distinct races in North America. The race occurring in the Pacific Northwest of North America has previously been shown to have originated by polyploidy from a different set of ancestral tetraploids than the nominal, Amphi‐Atlantic race. These two races differ also in a number of morphological characters, which has been a historical source of confusion. We here propose a new name for the western plants, V. pluviae Marcussen, H.E. Ballard & Blaxland, and typify it with a specimen collected near Mt Rainier (USA, Washington) with known chromosome number. Distribution, phylogenetic history and taxonomy are discussed and an updated morphological key to the Pacific Northwestern species of Viola is presented.     

Differences in muscle contractile characteristics among bodybuilders, endurance trainers and control subjects

The purpose of this investigation was to compare the myosin heavy chain (MHC) isoform expression of the triceps brachii muscle and isoinertial, isometric and isokinetic strength indices in competitive bodybuilders (CB, n = 5), recreational resistance trainers (RT, n = 5), endurance-trained rowers (ER, n = 5) and control (C, n = 5) subjects. Muscle tissue samples were analysed for MHC isoform content using 6% sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The CB possessed significantly smaller (P < 0.05) percentage of MHC type IIb proteins [12.92 (SD 7.08)%] than RT [30.08 (SD 6.58)%] ER [31.20 (SD 2.74)%] and C [38.22 (SD 2.95)%] groups (i.e. CB < RT ≈ ER < C). While the content of MHC type IIa isoforms did not differ significantly between the two resistance-trained groups [CB = 55.76 (SD 5.38)%; RT = 45.72 (SD 7.8)%], CB presented significantly more type IIa MHC isoforms than ER [42.84 (SD 2.98)%] and C [34.72 (SD 1.57)%] subjects (i.e. CB ≈ RT > ER ≈ C). The MHC type I protein content did not differ significantly among RT [24.20 (SD 4.89)%] ER [25.38 (SD 1.67)%] and C [27.06 (SD 1.81)%] groups. The CB [31.32 (SD 2.67)%] presented significantly more type I MHC isoforms only in comparison with RT. However, when changes in the percentage of MHC type I isoforms were converted to effect sizes (ES), it appeared that low statistical power rather than the absence of an effect accounted for the nonsignificant differences between CB and other groups (i.e. CB > RT ≈ ER ≈ C). Significant differences existed in isoinertial strength among the trained athletes (i.e. CB > RT > ER ≈ C), while isometric and isokinetic strength were not significantly different among any of the trained groups. However, the ES transformation of data demonstrated that large differences existed between resistance-trained groups and ER for isometric and isokinetic strength (i.e. CB ≈ RT > ER ≈ C). A statistically significant negative correlation (P < 0.001) was found between MHC type IIb isoforms and isoinertial strength index (r = − 0.68). The MHC type IIa proteins were positively related to all the strength measures considered (r = 0.51 – 0.61; P < 0.001). These data demonstrated different patterns of MHC isoform expression among the different groups of athletes and it is suggested that these differences on occasion may affect the expression of strength. Accepted: 24 September 1996     

Cellular Localization, Expression, and Structure of the Nuclear Dot Protein 52

Nuclear dots containing PML and Sp100 proteins (NDs) play a role in the development of acute promyelocytic leukemia, are modified after infection with various viruses, and are autoimmunogenic in patients with primary biliary cirrhosis (PBC). PML and Sp100 gene expression is strongly enhanced by interferons (IFN). Based on immunostaining with a monoclonal antibody (mAb C8A2), a third protein, nuclear dot protein 52 (NDP52), was recently localized in NDs. Here we analyzed the cellular localization, expression, and structure of NDP52 in more detail. Our NDP52-specific sera revealed mainly cytoplasmic staining but no ND pattern, neither in untreated nor in IFN-treated cells. Cells transfected with NDP52 expression vectors showed exclusively cytoplasmic staining. In subcellular fractionation experiments, NDP52 was found in cytoplasmic and nuclear fractions. Unlike as described for Sp100 and PML, NDP52 mRNA and protein levels were only marginally enhanced by IFN γ and not enhanced at all by IFN β. NDP52 homodimerization but no heterodimerization with Sp100 or PML could be demonstrated. None of the 93 PBC sera tested contained autoantibodies against NDP52. Finally, mAb C8A2 reacted not only with NDP52 but also with a conformation-dependent epitope on the Sp100 protein. These data imply that NDP52 forms homodimers but no heterodimers with Sp100 and PML, lacks autoantigenicity in PBC, localizes mainly in the cytoplasm, and is associated with the nucleus, but not with NDs. Finally, unlike Sp100 and PML, NDP52 expression is neither markedly enhanced nor localization detectably altered by type I and II IFNs.     

Growth of Thiobacillus ferrooxidans: a Novel Experimental Design for Batch Growth and Bacterial Leaching Studies

The concentrations of ferrous and ferric ions change dramatically during the course of the batch experiments usually performed to study the kinetics of the bacterial oxidation of ferrous ions and sulfide minerals. This change in concentration of the iron species during the course of the experiment often makes it difficult to interpret the results of these experiments, as is evidenced by the lack of consensus concerning the mechanism of bacterial leaching. If the concentrations of ferrous and ferric ions were constant throughout the course of the batch experiment, then the role of the bacteria could be easily established, because the rate of the chemical leaching should be the same at a given redox potential in the presence and in the absence of bacteria. In this paper we report an experiment designed to obtain kinetic data under these conditions. The redox potential is used as a measure of the concentrations of ferrous and ferric ions, and the redox potential of the leaching solution is controlled throughout the experiment by electrolysis. The effects of ferrous, ferric, and arsenite ions on the rate of growth of Thiobacillus ferrooxidans on ferrous ions in this redox-controlled reactor are presented. In addition, the growth of this bacterium on ferrous ions in batch culture was also determined, and it is shown that the parameters obtained from the batch culture and the redox-controlled batch culture are the same. An analysis of the results from the batch culture indicates that the initial number of bacteria that are adapted to the solution depends on the concentrations of ferrous and arsenite ions.     

Prey-handling and the evolutionary ecology of sand-swimming lizards (Lerista : Scincidae)

Fossorial lizards differ in morphology from their surface-dwelling relatives. The Australian sphenomorphine skink genus Ctenotus consists of surface-dwelling species, and is closely related to the genus Lerista, which includes both surface-dwelling and fossorial species. Sand-swimming represents the derived condition and has evolved independently in several lineages of Lerista. The heads of lizards in the two genera differ in shape (blunt snout for Ctenotus versus wedge-shaped for Lerista) and in length relative to the body (approximately 20% of snout-vent length for Ctenotus versus 12% for sand-swimming Lerista). Do these specializations affect the sizes or types of prey that can be consumed by Lerista? We compared prey-handling by Ctenotus and Lerista to correlate morphological differences with differences in prey-handling ability, and to distinguish the effects of snout shape and head length. Feeding trials included three categories of insect prey that the lizards normally eat: soft-bodied larvae (Lepidoptera), hard-bodied larvae (Coleoptera), and roaches (Blatoidea). In comparisons based on the mass of a prey item relative to the mass of a lizard, Lerista had longer handling times for all prey categories and were limited to smaller prey than were Ctenotus. However, when comparisons were based on the length of prey relative to the length of a lizard's head, Lerista ate some elongate prey as fast or faster than did Ctenotus, and both genera successfully swallowed prey more than twice the length of their own head. Thus, the differences in prey-handling performance of Ctenotus and Lerista probably result from the fact that Lerista have a relatively shorter head than Ctenotus. All Lerista species, surface-dwelling and fossorial, have short heads compared to primitive sphenomorphine lizards. Fossorial species of Lerista have elongate trunks, and consequently their heads are shorter in proportion to trunk length than those of surface-dwelling Lerista. However, most fossorial species of Lerista are longer and heavier than any of their surface-dwelling congeners, and the heads of these fossorial species are large relative to the prey they encounter. As a consequence, the diets of large fossorial species of Lerista do not appear to be limited by their morphological specialization for sand-swimming.     

Amphiphysin Heterodimers: Potential Role in Clathrin-mediated Endocytosis

Amphiphysin (Amph) is a src homology 3 domain-containing protein that has been implicated in synaptic vesicle endocytosis as a result of its interaction with dynamin. In a screen for novel members of the amphiphysin family, we identified Amph2, an isoform 49% identical to the previously characterized Amph1 protein. The subcellular distribution of this isoform parallels Amph1, both being enriched in nerve terminals. Like Amph1, a role in endocytosis at the nerve terminal is supported by the rapid dephosphorylation of Amph2 on depolarization. Importantly, the two isoforms can be coimmunoprecipitated from the brain as an equimolar complex, suggesting that the two isoforms act in concert. As determined by cross-linking of brain extracts, the Amph1–Amph2 complex is a 220- to 250-kDa heterodimer. COS cells transfected with either Amph1 or Amph2 show greatly reduced transferrin uptake, but coexpression of the two proteins rescues this defect, supporting a role for the heterodimer in clathrin-mediated endocytosis. Although the src homology 3 domains of both isoforms interact with dynamin, the heterodimer can associate with multiple dynamin molecules in vitro and activates dynamin’s GTPase activity. We propose that it is an amphiphysin heterodimer that drives the recruitment of dynamin to clathrin-coated pits in endocytosing nerve terminals.