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In the present study we examined the expression and release of the extracellular matrix glycoprotein fibronectin (FN) in a prostate cancer cell line (LNCaP) and in primary prostatic stromal cells using the reverse transcription-polymerase chain reaction (RT-PCR) and by an enzyme-linked immunosorbent assay. Perturbation experiments in vitro using antibodies directed against FN and the FN receptor were also performed. Immunohistochemistry was used to show the in vivo distribution of FN and the FN receptor in tissue sections of normal human prostate, benign prostatic hyperplasia, and prostate carcinoma. The expression of the oncofetal FN ED-B segment in benign prostatic hyperplasia and prostate carcinoma tissue was investigated by RT-PCR. The FN mRNA was expressed by LNCaP and primary prostatic stromal cells, respectively. Both cell types released FN into the medium in a time-dependent manner, whereby FN secretion was about 2.5-fold higher in cultures of stromal cells relative to LNCaP cells. Blocking FN with anti-FN antibodies resulted in a significant decrease in cell adhesion for LNCaP cells and a change in morphology for the primary stromal cells. FN was located mainly in the stromal compartment of the prostate, showing a distinct distribution pattern in prostate carcinoma, whereas the FN receptor was detectable only in the prostate epithelia. RT-PCR experiments showed the expression of the oncofetal FN ED-B segment in benign prostatic hyperplasia and prostate carcinoma tissue, with a 3.5-fold higher expression in the prostate carcinoma probes. Our data point to an important role for FN in cell adhesion of prostatic cells and show that an alternatively spliced FN mRNA is upregulated in the pathologically altered human prostate.

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Research in remote locations is more expensive than similar activities at sites with easier access, but these costs have rarely been compared. Using examples from seabird research, we show that conducting research in the Arctic is typically eight times more expensive than pursuing similar studies at a southern location. The differences in costs are related principally to the much higher expenses of travel and shipping (typically 4–10× higher for Arctic work), as well as the good practice of meaningful engagement with northern communities (4%–25% of project costs). Although there is some variation in costs among Arctic countries, we hope that the consistent pattern of relatively higher Arctic costs allows policy-makers and funding agencies to better plan for research support, especially for this region that is experiencing rapid environmental change.

Successful conservation of threatened species is often hindered by a lack of long-term data required to identify the vital rates contributing to population decline and the extrinsic factors influencing those rates. Museum collections can provide a valuable resource for reconstructing the historic demography and diet of otherwise elusive species. Here, we used age ratios (the relative number of hatch-year to after-hatch-year individuals) to examine the hypothesis that population declines in a threatened seabird, the marbled murrelet Brachyramphus marmoratus, are due to declines in reproductive success over the past 150 yr. We also used stable-nitrogen isotopes to examine the hypothesis that variation in reproductive success over this period is related to the quality of food received by young in the nest. Age ratios from at-sea surveys conducted from 1994 to 2001 were significantly lower than museum collection age ratios for the period 1860 to 1950. Stable-nitrogen isotope values indicated that the trophic feeding level of marbled murrelet nestlings declined significantly (-2.6 ‰) from 1854 to 2008. Our results suggest that the reproductive success of marbeled murrelets breeding in the Salish Sea has declined over the past 150 yr and that declines in nestling diet quality may be partly responsible. Overall, our results support the idea that managers should consider the quality of both nesting and marine foraging habitat as they attempt to improve reproductive success and population growth rate in this threatened species.KEY WORDS: Marbled murrelet · Stable isotopes · Age ratios · Diet reconstruction · Museum specimens · Brachyramphus marmoratus · Salish Sea Resale or republication not permitted without written consent of the publisher Contribution to the Theme Section 'Forensic methods in conservation research' OPEN PEN ACCESS CCESS

The Canadian Arctic hosts millions of marine birds annually, many of which aggregate in large numbers at well-defined sites at predictable times of the year. Marine habitats in this region will be under increasing threats from anthropogenic activities, largely facilitated by climate change and long-term trends of reduced sea ice extent and thickness. In this review, we update previous efforts to delineate the most important habitats for marine birds in Arctic Canada, using the most current population estimates for Canada, as well as recent information from shipboard surveys and telemetry studies. We identify 349 160 km2 of key habitat, more than doubling earlier suggestions for key habitat extent. As of 2018, 1% of these habitats fall within the boundaries of legislated protected areas. New marine conservation areas currently being finalized in the Canadian Arctic will only increase the proportion protected to 13%.

Glucocorticoids are anti inflammatory stress hormones and have been suggested to be involved in a large number of pathological processes. To test the effects of glucocorticoids on stromal prostatic cell growth and proliferation in vitro, the influence of a synthetic glucocorticoid (dexamethasone, dex) on recently established human primary cells from prostatic stroma (hPCPs) was analysed. The localization and distribution of the glucocorticoid receptor (GR) was investigated by immunohistochemistry. In addition, expression of the active isoform of the receptor (alpha-GR) was examined by reverse transcription PCR, and the effect of different doses of dex on proliferation of the stromal cells evaluated using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and amido black assays. alpha-GR mRNA was expressed by the hPCPs, and the GR protein was detected in the cytoplasm and nucleus of these cells. Incubating the cells with dex resulted in an enhanced cell proliferation that was mainly restricted to the fibroblasts. Moreover, fibronectin (FN) gene expression and secretion of the protein was increased by high doses of dex (> or = 10(-8) M), whereas low doses of dex (10(-10)M) showed no effect. Human prostatic stromal cells show sensitivity to dex in vitro, resulting in an increase in cell proliferation and FN synthesis. The authors assume that locally accumulating glucocorticoids can also influence the regulation of cell growth and extracellular matrix synthesis in the human prostate in vivo and may play a role in the pathologically altered prostate.

Identifying factors that influence growth throughout development is important for understanding the consequences of variation in resource quality on recruitment. Marbled Murrelets ( Brachyramphus marmoratus (J.F. Gmelin, 1789)) are threatened seabirds that are extremely cryptic in their nesting behaviour, which makes it challenging to understand how juveniles allocate resources during development. From a single capture at sea, we analyzed stable carbon isotopes in feathers and blood of juvenile murrelets to infer diet composition during both the pre- and the post-fledging periods. Consistent with the challenges juveniles face during their first year of life, we found that wing and bill growth were prioritized in the nest, whereas development of energy stores was delayed until after nest departure. We also found that diet quality after nest departure influenced bill size and body condition, two body components that continue to grow after independence. Our results provide evidence that murrelets strategically allocate resources according to their stage of development and that the availability of high-quality prey is likely to be important to juvenile development. These results identify a potential mechanism through which feeding conditions may influence reproduction of murrelets and demonstrate the utility of stable isotopes to examine the influence of diet quality on growth over multiple stages of development.