Although the nematode Caenorhabditis elegans produces self-fertile hermaphrodites, it descended from a male/female species, so hermaphroditism provides a model for the origin of novel traits. In the related species C. remanei, which has only male and female sexes, lowering the activity of tra-2 by RNA interference created XX animals that made spermatids as well as oocytes, but their spermatids could not activate without the addition of male seminal fluid. However, by lowering the expression of both tra-2 and swm-1, a gene that regulates sperm activation in C. elegans, we produced XX animals with active sperm that were self-fertile. Thus, the evolution of hermaphroditism in Caenorhabditis probably required two steps: a mutation in the sex-determination pathway that caused XX spermatogenesis and a mutation that allowed these spermatids to self-activate.
With better detection and treatment, breast cancer is less likely to be the primary cause of death in the majority of breast cancer survivors; mortality due to cardiovascular disease (CVD) is now more common. Given the long latency periods between cancer treatment completion and potential symptomatic CVD, there is a need to detect vascular changes before symptoms appear. This short review provides an overview of non-invasive, widely available, and relatively inexpensive techniques for assessing endothelial function, central and regional arterial stiffness, central blood pressures, and intima-media thickness. These tools exhibit acceptable reliability and validity, and are relatively practical. Clinical assessment recommendations are also provided. There is sufficient evidence to encourage the use of these techniques as a component of routine serial assessments, and to help guide appropriate treatment strategies.
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