1993 — 2012 |
Mowry, Kimberly L |
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. |
Rna Localization in Xenopus Oocytes
Establishment of polarity in the egg can be described as the earliest step in embryonic patterning. A single cell, the fertilized egg, contains the information that will ultimately specify the entire organism. As the egg divides during the early stages of development, different cells acquire different fates. One mechanism to account for this difference in developmental potential is the sequestering of molecules in the egg that could specify such potential. It is a long-standing proposal that localization of maternal factors in eggs can provide the basis for pattern in the early embryo, and while there is evidence for the existence of localized cytoplasmic determinants in many systems, in no case is the localization process understood. This research proposal addresses this problem by investigating the localization of specific maternal mRNAs in the frog egg. The aim of the proposed research is to understand the means by which RNA is localized to specified regions within a cell. The Xenopus oocyte provides an excellent model system in which to study this problem. Chief among the experimental advantages in this system are a rapid injection assay for localization, and ease in obtaining large amounts of material for biochemical studies. Three lines of investigation are proposed to study RNA localization: (1) Experiments are proposed to identify and isolate components of the localization apparatus. The biochemistry of RNA localization is not currently understood. By addressing this issue, new information should be gained concerning the molecular apparatus involved in moving macromolecules to defined regions of the oocyte cytoplasm. (2) To address certain mechanistic questions, experiments are proposed to probe the role of the cytoskeleton in RNA localization. (3) In order to allow understanding of how particular RNAs are recognized as requiring localization, experiments are proposed to characterize the RNA signal for localization. These experiments may provide insights not only into how developmental signals are localized, but also the role this may play in cell type determination. Currently, it is not understood how developmental signals are localized to determine cell type during early development. The experiments proposed here address that problem, and may contribute towards understanding how developmental programs are disrupted in certain diseases. To understand the means by which cellular processes can go awry, it will first be necessary to gain a basic understanding of normal development and differentiation.
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1 |
1998 — 2002 |
Mowry, Kimberly |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Cell Polarity and Localized Maternal Proteins in Xenopus
9728053 Mowry
Establishment of polarity in the egg can be described as the earliest step in embryonic patterning. A single cell, the fertilized egg, contains the information that will ultimately specify the entire organism. As the egg divides during the early stages of embryonic development, different cells acquire different fates. One mechanism to account for this difference in developmental potential among the cleavage cells is the sequestering of molecules in the egg that could specify such potential. It is a long-standing proposal that localization of such determinants prior to fertilization can provide the basis for pattern formation in the early embryo. While there is evidence for the existence of localized cytoplasmic determinants in many systems, the identities of such determinants remain largely unknown in vertebrates, and the mechanisms for establishment of polarity in the oocyte are poorly understood.
In eggs of the frog, Xenopus laevis, cell polarity is readily apparent along the animal/vegetal (AV) axis, which represents an axis of developmental potential whereby specific cell fates are assigned with respect to the AV axis. What is not known are the identities of all the presumptive maternal determinants, and how they come to be properly localized in the oocyte. Such determinants can be localized as mRNA or protein; localized mRNAs are well documented in the Xenopus oocyte, and some are thought to play roles in axial patterning. While it is apparent that not all of the localized maternal components are RNAs, little progress has been made on identifying localized maternal protein determinants.
The goal of the proposed research is to identify and characterize localized maternal protein determinants in the Xenopus egg. The foundation for this work has been laid by Dr. Mowry's success in devising a subtractive immunization scheme to obtain monoclonal antibodies specific for proteins that are localized in the frog egg. Focusing their efforts on two of these vegetally localized proteins, three specific objectives are proposed: I. They will characterize the localized proteins at both the molecular and cytological levels. II. They will probe functions of the localized proteins in patterning and polarity. III. They will investigate the mechanism by which these proteins are restricted to the vegetal cortex.
These experiments are designed to investigate how developmental signals are spatially distributed to underlie patterning in the vertebrate embryo, and may also provide insight into how into how polarity is established in the oocyte.
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0.915 |
1999 — 2002 |
Valles, James [⬀] Mowry, Kimberly |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Manipulation of Cell Division With Static Magnetic Fields
While many aspects of mitosis and cytokinesis have been elucidated, a vast amount of ongoing work focuses on these fundamental processes showing that much remains for discovery and resolution. Advances in microscopy and immunocytochemistry and techniques for the mechanical, optical and biochemical manipulation of cells and their components have traditionally led and continue to lead to substantial progress in this field. Valles and coworkers recently discovered that early cleavages (cell divisions) of embryos of the frog, Xenopus laevis, align with a large static magnetic field. The reorientation of cleavages depends systematically on field strength and orientation and does not depend on field gradients. This novel discovery presents opportunities for dissecting interactions between cells and magnetic fields and potentially developing a new tool for manipulating cells and studying cell division. The two specific objectives address these opportunities.
Specific Objective 1: Determine the cleavage plane reorientation mechanism- While some systematics of this effect have been established, the mechanism has not. To achieve this goal, they will subject sets of frog embryos to magnetic fields during different periods of their cell cycle to identify when the influence of the magnetic field is strongest. They will use immunocytochemistry and confocal microscopy techniques to image the orientation and morphology of the microtubules of embryos exposed to the magnetic field to determine the influence of the magnetic field.
Specific Objective 2: Determine whether microtubules in vivo align with a magnetic field -Cellular structures that are likely to be involved in the reorientation by magnetic field are those composed of microtubules. Microtubules comprise a major portion of the mitotic apparatus and recent measurements have shown that individual microtubules align in vitro in a magnetic field. Because of the importance of microtubules to the cleavage plane reorientation effect and to many other cell processes, the second goal is to image the microtubules in magnetic field exposed frog embryos to discern whether or not they are tending to align with the field direction. Immunocytochemistry and confocal microscopy techniques will be used to image the astral microtubules in field exposed, Xenopus embryos and compare the observed microtubule shapes to those calculated using the known properties of microtubules. If the microtubules do align then the possibility exists that other microtubule dependent cell processes can be manipulated with magnetic fields. If they do not, then the microtubules in living systems have properties that differ from their in vitro counterparts. Examining the source of such differences can provide insight into in vivo processes.
Together, these experiments should provide fundamentally new insight into the interactions between magnetic fields and matter that might lead to general rules about those interactions and the potential for "magneto-manipulation" as a viable research tool.
This project is jointly supported by the Cell Biology Program in the Division of Molecular Biosciences, Directorate for Biological Sciences (BIO) and the Office of Multidisciplinary Activities (OMA) in the Directorate for Mathematical and Physical Sciences (MPS).
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0.915 |
2005 — 2008 |
Mowry, Kimberly L. |
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. |
Rna Localization in Xenopus Ooctytes
DESCRIPTION (provided by applicant): Establishment of polarity in the egg can be viewed as the earliest step in embryonic patterning. Thus, differences in cell fate among the early cleavage cells are a consequence of asymmetric distributions of informational molecules in the egg cytoplasm before fertilization, the basis for such polarity can be provided by localized maternal determinants in the form of mRNA. While there is evidence for the existence of localized determinants in many systems, the localization process is only now being unraveled. Among vertebrates, Vg1 mRNA is a prominent example of a localized mRNA that is thought to play a role in patterning. Vg1 mRNA encodes a growth factor-like molecule, and is localized during oogenesis to the vegetal cytoplasm of Xenopus oocytes. Restricted expression of Vgl protein in the vegetal hemisphere of the egg appears to be critical for correct patterning of the embryo, making Iocalization of Vg1 mRNA an important model for understanding how maternal molecules are localized to influence pattern and polarity. The goal of this research project is to investigate how RNA molecules can be targeted to specific regions of the cell cytoplasm to generate spatially restricted gene expression. The foundation for this investigation has been laid by our recent work studying the interactions between trans-acting localization factors and essential targeting sequences within Vg1 mRNA. We have identified and characterized key components of the localization machinery and defined consensus sequence elements within an RNA targeting signal. Moreover, we have discovered that the localization pathway initiates in the nucleus and we have uncovered distinct nuclear and cytoplasmic steps in the localization pathway. We now seek to extend these findings to elucidate the molecular mechanisms responsible for localized expression of Vg1 RNA with the following specific aims: I) To analyze nuclear events leading to cytoplasmic RNA localization. II) To characterize assembly and transport of the cytoplasmic RNP complex. III) To probe coordination of mRNA localization with other post-transcriptional control points. The proposed research is designed to provide mechanistic insight into how developmental signals are spatially distributed in the vertebrate embryo.
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1 |
2008 — 2019 |
Mowry, Kimberly L. |
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. |
Training in Molecular and Cell Biology and Biochemistry
? DESCRIPTION (provided by applicant): Continued support is requested for graduate training in Molecular and Cell Biology and Biochemistry for a talented cohort of predoctoral students in the Graduate Program in Molecular Biology, Cell Biology and Biochemistry (MCB) at Brown University. The MCB Graduate Program is an interdepartmental interdisciplinary program, which admits 8-12 students per year based on both their research and academic achievements. During the second or third year of graduate study, trainees will be selected from the ~20 eligible MCB graduate students for appointment to the training grant on the basis of their potential for success in research. Each year, 4 or 5 trainees will be appointed for a period of two years; funds to support 9 trainees per year are requested. Faculty trainers in the MCB Graduate Program are accomplished scientists who are drawn from 12 Departments at Brown University and the Warren Alpert Medical School, as well as from the Marine Biology Laboratory at Woods Hole. The mission of the MCB Graduate Program is to train the next generation of scientists to probe the molecular mechanisms of cellular and developmental processes. While the ultimate goal of advanced study in experimental biology is specialization, the MCB Graduate Program balances this focus with broad multidisciplinary training, equipping our students to pursue issues central to basic biology and human health without approach-imposed limitations. This comprehensive perspective sets the multidepartmental MCB Graduate Program apart from the eight other discipline-specific training programs at Brown, providing a unique opportunity for students to erase the boundaries between fields.
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1 |
2015 — 2018 |
Mowry, Kimberly L. |
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. |
Mechanisms of Rna Localization in Oocytes
? DESCRIPTION (provided by applicant): Establishment of polarity in the egg can be viewed as the earliest step in embryonic patterning. Thus, differences in cell fate among the early cleavage cells are a consequence of asymmetric distributions of informational molecules in the egg cytoplasm before fertilization. In a wide variety of organisms, the basis for such polarity can be provided by localized maternal determinants in the form of mRNA. Among vertebrates, Vg1 mRNA is a prominent example of a localized mRNA that plays a role in embryonic patterning. Restricted expression of Vg1 protein in the vegetal hemisphere of the egg is critical for correct patterning of the embryo, making localization of Vg1 mRNA an important model for understanding how maternal molecules are localized to influence pattern and polarity. The goal of this research project is to investigate the mechanisms that direct targeting of mRNAs to specific regions of the cell cytoplasm to generate cell and developmental polarity. The foundation for this investigation has been laid by our progress studying the molecular pathway that directs maternal mRNA molecules to the vegetal cortex of the Xenopus oocyte. Through development of approaches to track mRNA transport in live oocytes and biochemical strategies to isolate transport complexes, our experiments have uncovered new steps in the pathway and revealed new components of the cellular transport machinery. Our current proposal seeks to capitalize on these findings in order to delineate the molecular pathway that orchestrates delivery of maternal mRNAs to their cytoplasmic destinations. Three specific aims are proposed: In Aim 1, we will analyze the molecular interactions that drive vegetal RNP transport granule assembly, in Aim 2, we will determine the mechanisms that regulate directionality during RNA transport and in Aim 3 we will investigate the mechanisms that control retention of localized RNAs at the oocyte cortex. The proposed research is designed to reveal the mechanisms by which mRNA molecules are transported within cells to generate spatially restricted protein expression, and will provide insight into how developmental signals are spatially distributed in the vertebrate embryo. This work will impact issues related to human health such as birth defects, as well as neurological diseases that have been linked to defective RNA transport and localized protein synthesis.
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1 |
2020 — 2021 |
Johnson, Mark Aikens (co-PI) [⬀] Johnson, Mark Aikens (co-PI) [⬀] Johnson, Mark Aikens (co-PI) [⬀] Johnson, Mark Aikens (co-PI) [⬀] Johnson, Mark Aikens (co-PI) [⬀] Johnson, Mark Aikens (co-PI) [⬀] Johnson, Mark Aikens (co-PI) [⬀] Larschan, Erica Nicole (co-PI) [⬀] Mowry, Kimberly L. |
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. |
Interdisciplinary and Inclusive Predoctoral Training in Molecular, Cellular, and Biochemical Sciences
PROJECT SUMMARY Solving the complex problems in human health and modern biology represents a major challenge for those who will lead biomedical research in the near and long-term future. The core disciplines of our training program?molecular biology, cell biology, and biochemistry?have led the way in development of innovations that are driving life sciences research and applications today. It is imperative that US life scientist training programs evolve to meet the demand for a diverse group of leaders who are trained in rigorous and transparent implementation and reporting of quantitative analysis of biological data. We recognize that this demand will require a change in training culture that focuses on a high standard of professional development for trainers and trainees. The objectives of this predoctoral training program are to: (1) Build and sustain an equitable and inclusive training environment for an increasingly diverse group of PhD students. (2) Integrate training in the design and implementation of rigorous and transparently reported experimentation throughout the program. (3) Integrate training in quantitative and computational approaches throughout training program. (4) Integrate career exploration and student professional development throughout the program. Faculty trainers in the Molecular Biology, Cell Biology, and Biochemistry Graduate Program (MCBGP) are accomplished scientists who are drawn from 11 Departments at Brown University and the Warren Alpert Medical School. The mission of the MCBGP is to train the next generation of leaders in biomedical research to probe the molecular mechanisms of cellular and biochemical processes by building and sustaining an equitable and inclusive training environment in which a diverse group of PhD students will successfully gain quantitative, conceptual, technical, and professional skills that will allow them to conduct the rigorous and reproducible research that interdisciplinary life science demands. The MCBGP admits 9-14 students per year based on their research and academic potential. During the first or second year of graduate study, trainees will be selected from the ~20 eligible MCB graduate students for appointment to the training grant on the basis of their potential for success in research. Each year, 4 first-year and 4 second-year predoctoral students will be supported; funds to support 8 trainees per year are requested.
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