RESUMO
Endosperm and embryo development are coordinated via epigenetic regulation and signaling between these tissues. In maize (Zea mays), the endosperm-embryo signals are not known, but endosperm cellularization is a key event for embryos to form shoots and roots. We screened seed mutants for nonautonomous functions in endosperm and embryo development with genetically nonconcordant seeds and identified the recessive mutant rough endosperm3 (rgh3). The wild-type Rgh3 allele is required in the endosperm for embryos to develop and has an autonomous role in embryo and seedling development. Endosperm cell differentiation is defective in rgh3. Results from endosperm cell culture indicate that rgh3 mutants remain in a proliferative state through mid-seed development. Rgh3 encodes the maize U2AF(35) Related Protein (URP), an RNA splicing factor involved in both U2 and U12 splicing. The Rgh3 allele produces at least 19 alternative splice variants with only one isoform encoding a full-length ortholog to URP. The full-length RGH3α isoform localizes to the nucleolus and displays a speckled pattern within the nucleoplasm, and RGH3α colocalizes with U2AF(65). A survey of alternatively spliced transcripts found that, in the rgh3 mutant, a fraction of noncanonical splicing events are altered. Our findings suggest that differentiation of maize endosperm cell types is necessary for embryos to develop. The molecular cloning of Rgh3 suggests that alternative RNA splicing is needed for cell differentiation, development, and plant viability.
Assuntos
Processamento Alternativo , Diferenciação Celular , Endosperma/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Zea mays/embriologia , Zea mays/genética , Agrobacterium tumefaciens/genética , Agrobacterium tumefaciens/metabolismo , Alelos , Sequência de Aminoácidos , Biomarcadores/metabolismo , Técnicas de Cultura de Células , Nucléolo Celular/genética , Nucléolo Celular/metabolismo , Clonagem Molecular , Cruzamentos Genéticos , Endosperma/embriologia , Endosperma/genética , Endosperma/metabolismo , Genes de Plantas , Teste de Complementação Genética , Dados de Sequência Molecular , Fenótipo , Células Vegetais/metabolismo , Proteínas de Plantas/genética , Polinização , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Alinhamento de Sequência , Translocação Genética , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismoRESUMO
BACKGROUND: Educating nurses about palliative and end-of-life (EOL) care is a high priority in health care settings. The purpose of this study was to assess nurses' perceived competency regarding the provision of palliative and EOL care to hospitalized patients. METHOD: This study surveyed nurses from 25 pediatric and adult acute and intensive care units (ICU; N = 583) Quantitative data analysis was descriptive and correlational. Qualitative data analysis identified themes of participant concerns. RESULTS: Data analysis revealed that perceived competency in palliative and EOL care is significantly higher in the ICU nurses (p <.0001). Mean scores were significantly higher when nurses had more than 10 years of experience (p <.0001). Open-ended responses indicated concerns regarding improved communication behaviors, decision making, and facilitation of continuity of care. CONCLUSION: The results provide guidance for development of palliative and EOL care nursing education programs tailored to address specific unit needs according to staff characteristics, patient population focus of care, and acuity level of care. J Contin Educ Nurs. 2017;48(7):329-336.