Molecular Signatures of Prostate Stem Cells Reveal Novel Signaling Pathways and Provide Insights into Prostate Cancer

BACKGROUND:The global gene expression profiles of adult and fetal murine prostate stem cells were determined to define common and unique regulators whose misexpression might play a role in the development of prostate cancer. METHODOLOGY/PRINCIPAL FINDINGS:A distinctive core of transcriptional regulators common to both fetal and adult primitive prostate cells was identified as well as molecules that are exclusive to each population. Elements common to fetal and adult prostate stem cells include expression profiles of Wnt, Shh and other pathways identified in stem cells of other organs, signatures of the aryl-hydrocarbon receptor, and up-regulation of components of the aldehyde dehydrogenase/retinoic acid receptor axis. There is also a significant lipid metabolism signature, marked by overexpression of lipid metabolizing enzymes and the presence of the binding motif for Srebp1. The fetal stem cell population, characterized by more rapid proliferation and self-renewal, expresses regulators of the cell cycle, such as E2f, Nfy, Tead2 and Ap2, at elevated levels, while adult stem cells show a signature in which TGF-beta has a prominent role. Finally, comparison of the signatures of primitive prostate cells with previously described profiles of human prostate tumors identified stem cell molecules and pathways with deregulated expression in prostate tumors including chromatin modifiers and the oncogene, Erg. CONCLUSIONS/SIGNIFICANCE:Our data indicate that adult prostate stem or progenitor cells may acquire characteristics of self-renewing primitive fetal prostate cells during oncogenesis and suggest that aberrant activation of components of prostate stem cell pathways may contribute to the development of prostate tumors

Different patterns of Robertsonian fusion pairing in Bovidae and the house mouse: the relationship between chromosome size and nuclear territories

NatuurwetenskappePlant- en DierkundePlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]

A novel categorisation system to organise a large photo identification database for white sharks Carcharodon carcharias

The white shark Carcharodon carcharias was one of the first elasmobranch species where photo identification was used to identify unique individuals. In this study, we propose guidelines that improve the current photo identification technique for white sharks by presenting a novel categorisation system. Using this method, a high-resolution photograph of the dorsal fin is placed on a standardised three-section grid. Notches associated with the trailing edge of the fin are counted and scored within each grid section. The number of notches in each grid section is then used to produce a three-part code that is utilised to systematically organise the individuals into a database. Our proposed system was tested on sharks photographed in the sampling area over a 27-month period (4 398 photographs) and the method significantly reduced the search time associated with identifying resighted individuals. Using the notches code, we were able to identify 426 different C. carcharias within the Dyer Island Nature Reserve (South Africa). Due to the inherent ease of use, the accuracy associated with this method, and the ability to ‘resight’ individuals rapidly within a large photographic database, this non-invasive technique presents a validated and feasible alternative for future white shark photo identification studies.Keywords: dorsal fin, fingerprint, notches code, South AfricaAfrican Journal of Marine Science 2014, 36(1): 59–6