1994 — 1995 |
Sanchez Alvarado, Alejandro |
F32Activity Code Description: To provide postdoctoral research training to individuals to broaden their scientific background and extend their potential for research in specified health-related areas. |
Homeotic Transformation--a Gene Expression Screen @ Carnegie Institution of Washington, D.C. |
0.919 |
1998 — 2002 |
Sanchez Alvarado, Alejandro |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Molecular Basis of Planarian Regeneration
The objective of this proposal is to use planarians as a metazoan model system in which to dissect and manipulate the molecular basis of animal regeneration. Planarians have been chosen as a model system because of their key position in metazoan phylogeny, their remarkable regeneration abilities, and the totipotential nature of these animals' regenerative stem cell population (neoblasts). First, we propose to identify and characterize the genes involved in specifying and maintaining anterior and posterior regeneration fates. We will accomplish this objective using a polymerase chain reaction-based gene-screen. The methodology involves the subtractive hybridization of cDNAs from regenerating and non-regenerating tissues, and then amplifying the enriched cDNAs unique to each tissue (see preliminary results). The gene-screen-isolated cDNAs will be characterized by sequencing, developmental Northerns and in situ hybridizations. Secondly, we will take advantage of the asexual and sexual reproductive strategies of planarians, and of their totipotential regenerative stem cells to develop the methodologies necessary for the production of transgenic animals. Transgenesis will allow functional testing of those genes whose sequence, developmental expression profile, and tissue specificity indicate potential regulatory roles during the process of regeneration. Once identified, the functional characterization of regeneration-specific genes in planarians will be vertically integrated to the study of regeneration in higher organisms. Ultimately, the genes identified in planarians, and their interactions during regeneration will define a series of useful molecular templates which will help unravel the more complex epigenetic processes of vertebrate regeneration, and uncover the factors which make regeneration permissive in some, but not all metazoans.
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1 |
2003 — 2018 |
Sanchez Alvarado, Alejandro |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. R37Activity Code Description: To provide long-term grant support to investigators whose research competence and productivity are distinctly superior and who are highly likely to continue to perform in an outstanding manner. Investigators may not apply for a MERIT award. Program staff and/or members of the cognizant National Advisory Council/Board will identify candidates for the MERIT award during the course of review of competing research grant applications prepared and submitted in accordance with regular PHS requirements. |
The Molecular Basis of Planarian Regeneration @ Stowers Institute For Medical Research
Our objective is to identify and functionally characterize the genes and genetic pathways underpinning metazoan regeneration. We propose to use the planarian Schmidtea mediterranea as a model system to address this problem because it is among the simplest cephalized bilaterians with complex organ systems that display extensive regenerative capacities: a decapitated animal will regenerate and functionally integrate a new head to the pre-existing tissues in under a week. In addition, such remarkable developmental plasticity is driven by an abundant and experimentally accessible population of totipotent stem cells known as neoblasts. The advances made during the last period of funding to interrogate gene function and measure regenerative responses, combined with the sequencing and recent annotation of the S. mediterranea genome create an unprecedented opportunity to frame the problem of animal regeneration in molecular and functional genomic terms. We propose to take full advantage of the throughput capacity and biological plasticity afforded by planarians to establish a detailed molecular landscape of regeneration. We propose to: 1) carry out genome- wide, high temporal resolution analyses of regeneration using high density DNA arrays; 2) test the functions of key, evolutionarily conserved embryonic signaling pathways in the adult contexts of tissue homeostasis and regeneration to provide a functional basis for interpreting the microarray experiments; and 3) to carry out screens of organ-specific regeneration to determine the regulatory extent and degree of molecular specialization that exists in general regenerative events. Combined, these studies should provide us with the most comprehensive mechanistic study of regeneration performed to date, and should serve as a platform to formally test the evolutionary divergence or convergence of regeneration among animals, a central unresolved aspect hindering the implementation of rational regenerative therapeutics in poor regenerators such as mammals.
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1 |
2009 — 2010 |
Piotrowski, Tatjana [⬀] Sanchez Alvarado, Alejandro |
RC1Activity Code Description: NIH Challenge Grants in Health and Science Research |
Analysis of Hair Cell Regeneration in Zebrafish @ Stowers Institute For Medical Research
DESCRIPTION (provided by applicant): A prominent cause of deafness is loss of hair cells due to age, noise or antibiotic treatments. In contrast to mammalian hair cells, fish, bird and amphibian hair cells are constantly turning over and regenerate following hair cell death. The aim is to take advantage of the lateral line of zebrafish to define and characterize the molecular and cellular interactions occurring during hair cell regeneration with the long-term goal of activating these pathways in mammals. To uncover the mechanisms driving hair cell regeneration, the lateral line of the zebrafish was chosen as an experimental paradigm because of 1) the ability of zebrafish support cells to regenerate hair cells;2) the functional and morphological similarity between the lateral line hair cells and the hair cells of the inner ear;3) its accessibility to direct observation and manipulation throughout development;and 4) the ability to rapidly and cost-effectively isolate specific cell types involved in hair cell regeneration, experiments that are difficult to perform in the classical model systems, e.g., mouse and chick. The two laboratories are pursuing the following strategy to identify the earliest genes that are transcribed in support cells subsequent to hair cell death. First, the location and population dynamics of stem cells and surrounding niche cells in normal and regenerating neuromasts will be determined, which is essential for determining the signals required for stem cell maintenance and activation. Secondly, the transcriptome of purified support cells will be defined using microarray analyses. To systematically analyze all candidate genes identified, a novel and powerful bioinformatics approach will be employed to identify genes co-regulated by the same transcription factors. Identifying these important transcription factors will be crucial for our understanding of how regeneration is triggered in lower vertebrates. Combined, these two approaches will discover key hair cell regeneration genes and set the stage for a systematic dissection of this complex problem to inform the development of therapeutics to regenerate hair cells in mammals. PUBLIC HEALTH RELEVANCE: Stem cells are crucial for adult tissue homeostasis and regeneration. The zebrafish lateral line is an excellent model to elucidate the genetic pathways controlling stem cells and sensory hair cell regeneration. Results from our studies will aid in the identification of stem cells in the mammalian ear and in the development of therapeutic strategies to regenerate hair cells in mammals.
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1 |
2009 |
Sanchez Alvarado, Alejandro |
T32Activity Code Description: To enable institutions to make National Research Service Awards to individuals selected by them for predoctoral and postdoctoral research training in specified shortage areas. |
Developmental Biology Training Program
DESCRIPTION (provided by applicant): This application requests continued support for an interdepartmental Developmental Biology Training Program at the University of Utah. This program provides support for training exceptional predoctoral and postdoctoral scientists in the field of Developmental Biology. The program consists of individualized research training under the guidance of 48 faculty members who work in one of six Ph.D. degree-granting departments within the University. The program director and interdepartmental Advisory Committee members select trainees, monitor their progress, and organize training program activities. Training is provided in a broad range of areas including gene regulation, cell differentiation, growth and morphogenesis, signal transduction, and developmental genetics. Prospective Ph.D. trainees are admitted to graduate school through the Molecular Biology and Neuroscience Graduate Programs, which dictate the core curriculum of the first year. Predoctoral and postdoctoral trainees are selected based on excellence in research and are supported for up to three years for predoctoral trainees and two years for postdoctoral trainees. The participation of six departments provides a diverse interdisciplinary training in Developmental Biology. A coherent structure is provided by the wide variety of interdepartmental activities fostered by the Molecular Biology and Neurosciences Programs, as well as the long history of cooperation and collaboration within the University community. All trainees are required to take a scientific ethics course, participate in an ongoing journal club related to developmental biology, take an advanced course in developmental biology, participate in and present a seminar in the Developmental Biology Discussion Group, participate in and present a research-based talk at an Annual Training Program Retreat, and host an outside seminar speaker. This is supplemented with vigorous seminar programs and inter-laboratory research-in-progress group meetings to ensure that the trainees receive a strong training in developmental biology, preparing them to direct their own independent research programs. The biochemical pathways that act during development also play important roles in human health and disease. For example, the programmed cell death pathway was first analyzed for its role in C. elegans development, as was much of the insulin pathway. These studies lead to the discovery of molecules that have now been implicated in human diseases such as cancer, diabetes, and most recently aging (e.g., caspases, FOXO transcription factors). Therefore, analysis of developmental processes, and training young scientists in the field of development, should prove indispensable for improving human health.
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1 |
2010 — 2013 |
Lewis, Suzanna E Sanchez Alvarado, Alejandro Yandell, Mark Douglas [⬀] |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Whole Genome Screen For Novel Regulators of Tissue Homeostasis and Regeneration
DESCRIPTION (provided by applicant): Whole genome screen for novel regulators of tissue homeostasis and regeneration Schmidtea mediterranea is a model system for addressing human health issues. Planarians are well known for their ability to regenerate complete animals from fragments of their bodies. Following recent demonstrations that S. mediterranea is amenable to modern cell, molecular, and RNAi techniques, it is becoming the model organism of choice for addressing research questions that cannot be easily studied in Drosophila melanogaster or Caenorhabditis elegans, including wound healing of adult tissues, regeneration, somatic stem cells, and tissue homeostasis. In 2007 we annotated the S. mediterranea genome and constructed a publicly available genome database, SmedGD containing the gene models. The objective of this grant is to use the S. mediterranea gene annotations in a high-throughput image-based screen for novel regulators of tissue regeneration and homeostasis. Toward this end we will (1) employ a battery of molecular and immunological techniques, including a genome-wide RNAi screen, and (2) leverage existing image processing, management and annotation tools to construct a cyberinfrastructure that can both support our experiments and distribute our results to the scientific community. PUBLIC HEALTH RELEVANCE: This project will use the sequenced genome of the planarian Schmidtea mediterranea to search for genes involved in tissue maintenance and regeneration. The project employs a number of exciting new technologies, including RNA interference, an automated confocal microscope, and image processing and annotation tools to achieve its aims. Because we will restrict our screen to planarian genes with bona fide human homologs, any stem cell function deficiency phenotype obtained becomes a potential model to study human stem-cell function, regeneration and wound healing, effectively advancing efforts in these frontiers of human health.
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1 |
2020 — 2021 |
Melosh, Nicholas (co-PI) [⬀] Wang, Bo Sanchez Alvarado, Alejandro |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Edge Ct: Developing Transgenic and Lineage Tracing Tools in Planarians
Planarians have captured the imagination of generations of scientists, and today play a critical role in our efforts to understand development and regeneration. These small flatworms can regenerate their entire body from small tissue fragments. As a result of the current surge in the sequencing technology, tremendous progress has been made over the past two decades to understand planarian biology from a variety of perspectives, including but not limited to regeneration, stem cell, animal body plan and evolution, germline, nervous system, metabolism, innate immunity, signaling pathways, regulatory RNAs, and genome stability. Yet the entire field has been limited by the lack of tools for transgene expression and genome editing. At the same time, technological innovation has exploded for transfection and gene editing of mammalian cells. In particular, nanotechnological approaches can very locally disrupt the cell membrane and inject molecular cargo directly, providing both low cell toxicity and high delivery efficiencies. In this project, the researchers will use the novel nanotechnology, "nanostraws," to deliver genetic materials into planarian cells, and provide a simple and effective means for transgene expression and genome editing. This project also aims to rapidly disseminate the new technology by facilitating data, protocol, and materials sharing across labs, and organizing training workshops. In addition, because of planarians' appealing regenerative ability, childlike cuteness, and ease to rear in the lab, the researchers will promote the usage of planarians in teaching, education, and outreach activities to engage non-scientists' interests in modern biological research.
Planarians have been a powerful animal model to study tissue regeneration and stem cell biology. They have the unique capacity to regenerate the entire body from minute tissue fragments using pluripotent somatic stem cells. During this process, they reset the body axes and rebuild all organs in appropriate proportions. Although extensive genomic and transcriptomic information is available, progress on addressing causal genotype-phenotype relationships in planarians has been severely hindered by a lack of transgenic tools despite decades of attempts. Enabled by the recent technical advances made in the investigators' laboratories, including cell culture and transplantation methods, novel nanotechnology for gene delivery in hard-to-transfect cell types, and successful expression of luminescence reporters in planarian cells, they aim to address this long-standing challenge. This research project aims to develop and disseminate the methodology and resources for planarian transgenesis. Specifically, the goals of this project include (1) to develop nanoscale electroporation methods for transgene delivery in planarian cells, (2) to demonstrate genome editing using CRISPR/Cas9, and (3) to enhance the collaboration, training, and diversity of the planarian research community to address a broad spectrum of questions in molecular, cellular, organismal, and evolutionary biology.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
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0.957 |