An epigenetically inherited UV hyper-resistance phenotype in Saccharomyces cerevisiae.

BACKGROUND: Epigenetics refers to inheritable phenotypic changes that occur in the absence of genetic alteration. Such adaptations can provide phenotypic plasticity in reaction to environmental cues. While prior studies suggest that epigenetics plays a role in the response to DNA damage, no direct demonstration of epigenetically inheritable processes have been described in this context. RESULTS: Here we report the identification of an epigenetic response to ultraviolet (UV) radiation in the baker's yeast Saccharomyces cerevisiae. Cells that have been previously exposed to a low dosage of UV exhibit dramatically increased survival following subsequent UV exposure, which we refer to as UV hyper-resistance (UVHR). This phenotypic change persists for multiple mitotic generations, without any indication of an underlying genetic basis. Pre-exposed cells experience a notable reduction in the amount of DNA damage caused by the secondary UV exposure. While the mechanism for the protection is not fully characterized, our results suggest that UV-induced cell size increases and/or cell wall changes are contributing factors. In addition, we have identified two histone modifications, H3K56 acetylation and H3K4 methylation, that are important for UVHR, potentially serving as mediators of UV protective gene expression patterns, as well as epigenetic marks to propagate the phenotype across cell generations. CONCLUSIONS: Exposure to UV radiation triggers an epigenetically inheritable protective response in baker's yeast that increases the likelihood of survival in response to subsequent UV exposures. These studies provide the first demonstration of an epigenetically inheritable dimension of the cellular response to DNA damage.

Understanding the views of parents of children with special needs about the nursing care their child receives when in hospital: a qualitative study.

This article reports a qualitative study designed to explore parents' views on how their child with additional needs had been cared for by hospital nursing staff, focusing on how well their own and their child's needs had been identified and met. Twelve interviews with parents of children with additional needs and a thematic analysis of the interview data was conducted. Four themes were developed to provide an insight into parents' views about their experiences: their prior experiences of hospital care, including the process of being told the original diagnosis; communication with staff; nurse-parent relationships; and perceptions of nurses and nursing care. It concludes that parents experience some difficulties in developing a trusting relationship with the nurses caring for their child with additional needs. Parents perceive that nurses are not always able to recognize and respond to their needs when caring for their child. Failure to address these needs can interfere with the development of effective nurse-parent relationships.