Condition-dependent sex: who does it, when and why?

We review the phenomenon of condition-dependent sex—where individuals' condition affects the likelihood that they will reproduce sexually rather than asexually. In recent years, condition-dependent sex has been studied both theoretically and empirically. Empirical results in microbes, fungi and plants support the theoretical prediction that negative condition-dependent sex, in which individuals in poor condition are more likely to reproduce sexually, can be evolutionarily advantageous under a wide range of settings. Here, we review the evidence for condition-dependent sex and its potential implications for the long-term survival and adaptability of populations. We conclude by asking why condition-dependent sex is not more commonly observed, and by considering generalizations of condition-dependent sex that might apply even for obligate sexuals. This article is part of the themed issue ‘Weird sex: the underappreciated diversity of sexual reproduction’.

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Survival of and In Situ Gene Expression by Vibrio vulnificus at Varying Salinities in Estuarine Environments

Applied and Environmental Microbiology ◽

10.1128/aem.02436-07 ◽

2007 ◽

Vol 74 (1) ◽

pp. 182-187 ◽

Cited By ~ 12

Author(s):

Melissa K. Jones ◽

Elizabeth Warner ◽

James D. Oliver

Keyword(s):

Gene Expression ◽

Vibrio Vulnificus ◽

Natural Habitat ◽

Term Survival ◽

Long Term Survival ◽

Wide Range ◽

Opportunistic Human Pathogen

ABSTRACT The opportunistic human pathogen Vibrio vulnificus survives in a wide range of ecological environments, which demonstrates its ability to adapt to highly variable conditions. Survival and gene expression under various conditions have been extensively studied in vitro; however, little work has been done to evaluate this bacterium in its natural habitat. Therefore, this study monitored the long-term survival of V. vulnificus in situ and simultaneously evaluated the expression of stress (rpoS, relA, hfq, and groEL) and putative virulence (vvpE, smcR, viuB, and trkA) genes at estuarine sites of varying salinity. Additionally, the survival and gene expression of an rpoS and an oxyR mutant were examined under the same conditions. Differences between the sampling sites in the long-term survival of any strain were not seen. However, differences were seen in the expression of viuB, trkA, and relA but our findings differed from what has been previously shown in vitro. These results also routinely demonstrated that genes required for survival under in vitro stress or host conditions are not necessarily required for survival in the water column. Overall, this study highlights the need for further in situ evaluation of this bacterium in order to gain a true understanding of its ecology and how it relates to its natural habitat.

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Effect of Revascularization on Long-Term Survival in Patients With Ischemic Left Ventricular Dysfunction and a Wide Range of Viability

The American Journal of Cardiology ◽

10.1016/j.amjcard.2010.03.014 ◽

2010 ◽

Vol 106 (2) ◽

pp. 187-192 ◽

Cited By ~ 12

Author(s):

Stephen G. Sawada ◽

Saumyadip Dasgupta ◽

James Nguyen ◽

Kathleen A. Lane ◽

Irmina Gradus-Pizlo ◽

...

Keyword(s):

Left Ventricular Dysfunction ◽

Ventricular Dysfunction ◽

Left Ventricular ◽

Term Survival ◽

Long Term Survival ◽

Wide Range

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Serological evidence of West Nile Virus (WNV) in mammalian species in Turkey

Epidemiology and Infection ◽

10.1017/s0950268805005492 ◽

2005 ◽

Vol 134 (4) ◽

pp. 826-829 ◽

Cited By ~ 33

Author(s):

A. OZKUL ◽

Y. YILDIRIM ◽

D. PINAR ◽

A. AKCALI ◽

V. YILMAZ ◽

...

Keyword(s):

West Nile Virus ◽

Neutralizing Antibodies ◽

Mammalian Species ◽

Serological Evidence ◽

West Nile ◽

Term Survival ◽

Long Term Survival ◽

Wide Range ◽

Overt Disease

In this study, the sera collected from a variety of mammalian species (ass-mules, cat, cattle, dog, horse, human and sheep) in 10 representative provinces of Turkey, were surveyed for the presence of neutralizing antibodies to West Nile virus (WNV). Overall, 1 of 40 (2·5%) ass-mules, 4 of 100 (4%) cattle, 43 of 114 (37·7%) dogs, 35 of 259 (13·5%) horses, 18 of 88 (20·4%) humans and 1 of 100 (1%) sheep, tested positive for WNV-neutralizing antibodies. The results indicate that a wide range of mammals are exposed to a West Nile-related virus and this could contribute to the long-term survival of this virus in the absence of overt disease.

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