Assuntos
Candidatura a Emprego , Universidades , Redação , Escolha da Profissão , Emprego , Humanos , Seleção de Pessoal , PesquisaRESUMO
The retinoblastoma gene Rb is the prototype tumor suppressor and is conserved in Drosophila. We use the developing fly retina as a model system to investigate the role of Drosophila Rb (rbf) during differentiation. This report shows that mutation of rbf and rhinoceros (rno), which encodes a PHD domain protein, leads to a synergistic delay in photoreceptor cell differentiation in the developing eye disc. We show that this differentiation delay phenotype is caused by decreased levels of different components of the Epidermal Growth Factor Receptor (EGFR) signaling pathway in the absence of rbf and rno. We show that rbf is required for normal expression of Rhomboid proteins and activation of MAP kinase in the morphogenetic furrow (MF), while rno is required for the expression of Pointed (Pnt) and Ebi proteins, which are key factors that mediate EGFR signaling output in the nucleus. Interestingly, while removing the transcription activation function of dE2F1 is sufficient to suppress the synergistic differentiation delay, a mutant form of de2f1 that disrupts the binding with RBF but retains the transcription activation function does not mimic the effect of rbf loss. These observations suggest that RBF has additional functions besides dE2F1 binding that regulates EGFR signaling and photoreceptor differentiation.
Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Receptores ErbB/metabolismo , Olho/metabolismo , Proteínas Nucleares/metabolismo , Células Fotorreceptoras de Invertebrados/metabolismo , Proteína do Retinoblastoma/metabolismo , Animais , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Diferenciação Celular/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Ativação Enzimática , Receptores ErbB/genética , Olho/crescimento & desenvolvimento , Proteínas de Ligação ao GTP/genética , Proteínas de Ligação ao GTP/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Homeodomínio , Imuno-Histoquímica , Larva/genética , Larva/crescimento & desenvolvimento , Larva/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Mutação , Proteínas Nucleares/genética , Fenótipo , Células Fotorreceptoras de Invertebrados/citologia , Proteína do Retinoblastoma/genética , Transdução de Sinais/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
The retinoblastoma gene Rb is a prototype tumor suppressor which is conserved in Drosophila. Although much is known about the roles of Rb in cell proliferation and apoptosis, much less is known about how Rb regulates cell differentiation. Inactivation of Drosophila Rb (rbf) exhibited subtle differentiation defects similar to inactivation of Rb in mice, suggesting the existence of redundant mechanisms in the control of cell differentiation. To test this possibility and to characterize the role of Rbf in cell differentiation during retinal development, we carried out a genetic screen and identified a mutation in rhinoceros (rno), which leads to synergistic differentiation defects in conjunction with rbf inactivation. Characterization of an early differentiation defect, the multiple-R8 phenotype, revealed that this phenotype was caused by limiting amounts of Notch signaling due to reduced expression of the Notch ligand, Delta (Dl). Decreasing the gene dosage of Dl enhanced the multiple-R8 phenotype, while increasing the level of Dl suppressed this phenotype. Interestingly, removal of the transcriptional activation of dE2F1 partially restores Dl expression in rbf,rno mutant clones and suppresses the associated differentiation defects, indicating that this differentiation function of RBF is mediated by its regulation of dE2F1 activity.
Assuntos
Diferenciação Celular/fisiologia , Proteínas de Drosophila/metabolismo , Fator de Transcrição E2F1/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Proteína do Retinoblastoma/metabolismo , Fatores de Transcrição/metabolismo , Animais , Animais Geneticamente Modificados , Proteínas de Drosophila/genética , Drosophila melanogaster/anatomia & histologia , Drosophila melanogaster/fisiologia , Fator de Transcrição E2F1/genética , Feminino , Dosagem de Genes , Peptídeos e Proteínas de Sinalização Intracelular , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Células Fotorreceptoras de Invertebrados/citologia , Células Fotorreceptoras de Invertebrados/patologia , Células Fotorreceptoras de Invertebrados/fisiologia , Proteína do Retinoblastoma/genética , Fatores de Transcrição/genéticaRESUMO
Grant writing is an essential skill to develop for academic and other career success but providing individual feedback to large numbers of trainees is challenging. In 2014, we launched the Stanford Biosciences Grant Writing Academy to support graduate students and postdocs in writing research proposals. Its core program is a multi-week Proposal Bootcamp designed to increase the feedback writers receive as they develop and refine their proposals. The Proposal Bootcamp consisted of two-hour weekly meetings that included mini lectures and peer review. Bootcamp participants also attended faculty review workshops to obtain faculty feedback. Postdoctoral trainees were trained and hired as course teaching assistants and facilitated weekly meetings and review workshops. Over the last six years, the annual Bootcamp has provided 525 doctoral students and postdocs with multi-level feedback (peer and faculty). Proposals from Bootcamp participants were almost twice as likely to be funded than proposals from non-Bootcamp trainees. Overall, this structured program provided opportunities for feedback from multiple peer and faculty reviewers, increased the participants' confidence in developing and submitting research proposals, while accommodating a large number of participants.