Cancer in Light of Experimental Evolution Sprouffske, Kathleen; Merlo, Lauren M.F.; Gerrish, Philip J. ...
CB/Current biology,
09/2012, Volume:
22, Issue:
17
Journal Article
Peer reviewed
Open access
Cancer initiation, progression, and the emergence of therapeutic resistance are evolutionary phenomena of clonal somatic cell populations. Studies in microbial experimental evolution and the ...theoretical work inspired by such studies are yielding deep insights into the evolutionary dynamics of clonal populations, yet there has been little explicit consideration of the relevance of this rapidly growing field to cancer biology. Here, we examine how the understanding of mutation, selection, and spatial structure in clonal populations that is emerging from experimental evolution may be applicable to cancer. Along the way, we discuss some significant ways in which cancer differs from the model systems used in experimental evolution. Despite these differences, we argue that enhanced prediction and control of cancer may be possible using ideas developed in the context of experimental evolution, and we point out some prospects for future research at the interface between these traditionally separate areas.
Beneficial mutations that arise in an evolving asexual population may compete or interact in ways that alter the overall rate of adaptation through mechanisms such as clonal or functional ...interference. The application of multiple selective pressures simultaneously may allow for a greater number of adaptive mutations, increasing the opportunities for competition between selectively advantageous alterations, and thereby reducing the rate of adaptation. We evolved a strain of Saccharomyces cerevisiae that could not produce its own histidine or uracil for ~500 generations under one or three selective pressures: limitation of the concentration of glucose, histidine, and/or uracil in the media. The rate of adaptation was obtained by measuring evolved relative fitness using competition assays. Populations evolved under a single selective pressure showed a statistically significant increase in fitness on those pressures relative to the ancestral strain, but the populations evolved on all three pressures did not show a statistically significant increase in fitness over the ancestral strain on any single pressure. Simultaneously limiting three essential nutrients for a population of S. cerevisiae effectively slows the rate of evolution on any one of the three selective pressures applied, relative to the single selective pressure cases. We identify possible mechanisms for fitness changes seen between populations evolved on one or three limiting nutrient pressures by high‐throughput sequencing. Adding multiple selective pressures to evolving disease like cancer and infectious diseases could reduce the rate of adaptation and thereby may slow disease progression, prolong drug efficacy and prevent deaths.
ABSTRACT We present results of a stellar occultation by the Jupiter Trojan asteroid Patroclus and its nearly equal size moon, Menoetius. The geocentric mid-time of the event was 2013 October 21 ...06:43:02 UT. Eleven sites out of 36 successfully recorded an occultation. Seven chords across Patroclus yielded an elliptical limb fit of 124.6 by 98.2 km. There were six chords across Menoetius that yielded an elliptical limb fit of 117.2 by 93.0 km. There were three sites that got chords on both objects. At the time of the occultation we measured a separation of 664.6 km (0.247 arcsec) and a position angle for Menoetius of 265 7 measured eastward from J2000 north. Combining this occultation data with previous light curve data, the axial ratios of both objects are 1.3 : 1.21 : 1, indicative of a mostly oblate ellipsoid with a slight asymmetry in its equatorial projection. The oblate shape is not an equilibrium shape for the current rotation period, but would be if it were rotating with an ∼8 h period. This faster period is consistent with a pre-evolved state of the system with an orbital separation that is 50% smaller. Our best estimate of the system density is 0.88 g cm−3.
Cetacean morbillivirus (CeMV) is an important global cause of morbidity and mortality in cetacean populations, with four pathological presentations including non-suppurative encephalitis. We describe ...an unusual case of dolphin morbillivirus (DMV)-associated non-suppurative encephalitis in a long-finned pilot whale (Globicephala melas), in which the lesions were orientated on the periventricular white matter and comprised prominent multifocal syncytia formation in the absence of systemic lesions. DMV RNA was detected in brain tissue by qRT-PCR and immunohistochemistry for morbillivirus antigen yielded intense labelling of syncytia in periventricular sites, with sparse involvement of the deeper neuroparenchyma. The pattern of lesions raises the possibility of viral dissemination through the cerebrospinal fluid, as described for canine distemper virus, suggesting that similar pathogenic mechanisms may be implicated in lesion development. Further investigation is required to establish the pathogenesis of CeMV encephalitis and the behaviour of the virus within the central nervous system of cetaceans.
Political Chronicles Wanna, John; Clune, David; Economou, Nick ...
The Australian journal of politics and history,
12/2014, Volume:
60, Issue:
4
Journal Article
Political Chronicles Wanna, John; Clune, David; Economou, Nick ...
The Australian journal of politics and history,
June 2014, Volume:
60, Issue:
2
Journal Article
Political Chronicles Wanna, John; Clune, David; Economou, Nick ...
The Australian journal of politics and history,
12/2013, Volume:
59, Issue:
4
Journal Article
Peer reviewed
Julia Gillard's prime ministership was under relentless pressure during the entire first half of 2013. Opinion polls did not markedly improve for her government and dissatisfaction remained ...pronounced with her performance as prime minister. Her ministers began to lose confidence on her stoic leadership; caucus became increasingly nervous as the election drew closer; and the media were incessantly critical of her performance, especially the metropolitan tabloids. Some sections of the media even began to publish a regular "Ruddwatch" to monitor the every move the former PM made, likening it to a cat stalking its ill-fated prey. To make matters worse, Gillard's party colleagues repeatedly questioned her political judgment, especially after she announced on 30 January that the next federal election would be held on 14 September 2013, giving over seven months' notice of the poll and throwing away one of the tactical advantages of incumbency. The plan was cooked up in her private office and she apparently had not told her cabinet colleagues. In the face of such unrelenting pressure, the stress began to show. Adapted from the source document.
Political Chronicles Wanna, John; Clune, David; Economou, Nick ...
The Australian journal of politics and history,
December 2012, Volume:
58, Issue:
4
Journal Article
Discussed are political events that occurred in Australia during the second half of 2012, including the scandals surrounding Prime Minister Julia Gillard. Adapted from the source document.
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