Progress 10/01/09 to 09/30/10
Outputs
OUTPUTS: Activities on this project include the execution and analysis of experiments, mentoring and teaching. Experiments were conducted with the help of a research specialist. One postdoctoral scholar, six undergraduate students, and two graduate students were mentored while contributing to this project. Research results were disseminated through oral and poster presentations at local and national conferences. In addition, this research was incorporated into a new advanced undergraduate genetics laboratory course. This lab exposes undergraduate students to discovery-based research and it contributes to the execution and analysis of experiments. PARTICIPANTS: Laura Mathies (PI) was responsible for guiding the research activities of all members of the research group. Zigrida Smith provided technical support for the research, including the preparation of reagents, maintenance of laboratory equipment, and execution of experiments. This project provided training and professional development for Karen Cole-Linton (Ph.D., University of Vermont), Edward Large (Ph.D., Genetics), Charlie Haz (M.R., Genetics), Brandon Kent (B.S., Biochemistry), Farah Jama (B.S., Biological Sciences), Dana Senko (B.S., Biological Sciences), Kathryn Westfall (B.S., Microbiology), Alex Lombardi (B.S. Biological Sciences), and Philip McDiarmid (B.S. Genetics). Collaborators include Dr. Julie Ahringer (MRC, England), Dr. Eric Haag (University of Maryland), Dr. Alex Deiters (NCSU Department of Chemistry) and Dr. John Cavanagh (NCSU Department of Biochemistry). TARGET AUDIENCES: This research was incorporated into the Genetics curriculum via an advanced genetics lab course. In this course, students learn to design and execute experiments, review the literature, analyze data, draw conclusions, and present their results in written and oral forms. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
This project uses the reproductive organs of the nematode C. elegans as a model to understand how genes control animal development. The reproductive organs are generated from precursor cells that have the potential to generate all tissues of the adult organ. These precursor cells divide to generate cells that are further restricted in their potential until they finally differentiate into the mature tissues of the organ. The somatic gonadal precursors (SGPs) are multipotent progenitor cells, while their sisters differentiate shortly after they are born. A novel tissue-specific RNAi approach is being employed to determine the genetic factors that distinguish the multipotent SGPs from their differentiated sisters. Precursor cells resemble stem cells, therefore this research may identify general features of stem cells.
Publications
- Large, E. E. and L. D. Mathies (2010). hunchback and Ikaros like zinc finger genes control reproductive system development in Caenorhabditis elegans. Developmental Biology 339(1): 51 64.
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Progress 10/01/08 to 09/30/09
Outputs
OUTPUTS: Activities on this project include the execution and analysis of experiments, mentoring and teaching. Experiments were conducted with the help of a research specialist. One postdoctoral scholar, four undergraduate students, and two graduate students were mentored while contributing to this project. Research results were disseminated through oral and poster presentations at local and national conferences. In addition, efforts are underway to incorporate this research into a new advanced undergraduate genetics lab to be offered in 2010. This lab will expose undergraduate students to discovery- based research and it will contribute to the execution and analysis of experiments. PARTICIPANTS: Laura Mathies (PI) was responsible for guiding the research activities of all members of the research group. Zigrida Smith provided technical support for the research, including the preparation of reagents, maintenance of laboratory equipment, and execution of experiments. This project has provided training and professional development for Karen Cole-Linton (Ph.D., University of Vermont), Edward Large (Ph.D. candidate, Genetics), Charlie Haz (Ph.D. candidate, Genetics), Brandon Kent (B.S., Biochemistry), Farah Jama (B.S., Biological Sciences), Dana Senko (B.S., Biological Sciences), and Kathryn Westfall (B.S., Microbiology). Collaborators include Dr. Julie Ahringer (MRC, England), Dr. Eric Haag (University of Maryland), Dr. Alex Deiters (NCSU Department of Chemistry) and Dr. John Cavanagh (NCSU Department of Biochemistry). TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
This project uses the reproductive organs of the nematode C. elegans as a model to understand how genes control animal development. The reproductive organs are generated from precursor cells that have the potential to generate all tissues of the adult organ. These precursor cells divide to generate cells that are further restricted in their potential until they finally differentiate into the mature tissues of the organ. Experiments conducted under this project provide evidence that precursor cells are critically dependent on the chromatin state. DNA is packaged into chromatin and this makes some genes more accessible than others. This result suggests that chromatin regulation may play a key role in the development of precursor cells. Precursor cells resemble stem cells, in that they can generate multiple cell types and they rely on chromatin regulation for their development. Therefore, research on the development of precursor cells in C. elegans may identify key aspects of stem cell development. Research conducted on this project also identified chromatin regulation as a mechanism for gene duplicates to acquire new functions.
Publications
- Richards, J.J., Reyes, S., Stowe, S.D., Tucker, A.T., Ballard, T.E., Mathies, L.D., Cavanagh, J., and C. Melander (2009). Amide Isosteres of Oroidin: Assessment of Antibiofilm Activity and C. elegans Toxicity. J. Med. Chem. 52(15): 4582-4585.
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Progress 10/01/07 to 09/30/08
Outputs
OUTPUTS: The primary activities on this project are the 1) execution and analysis of experiments and 2) mentoring and teaching. 1) Research results were disseminated through oral and poster presentations at local, regional, and international conferences. 2) Four undergraduate students and two graduate students were mentored while contributing to this project. In addition, the research was incorporated into laboratory exercises for two courses: Honors Principles of Genetics and Genes and Development. PARTICIPANTS: Laura Mathies (PI) was responsible for guiding the research activities of all members of the research group. Zigrida Smith provided technical support for the research, including the preparation of reagents, maintenance of laboratory equipment, and execution of experiments. This project has provided training and professional development for Edward Large (Ph.D., Genetics), Charlie Haz (Ph.D, Genetics), Brandon Kent (B.S., Biochemistry), Farah Jama (B.S., Biological Sciences), Diana Klompstra (B.S., Biological Sciences), and Kathryn Westfall (B.S., Microbiology) Collaborators include Dr. Julie Ahringer (MRC, England), Dr. Eric Haag (University of Maryland), Dr. Alex Deiters (NCSU Department of Chemistry). and Dr. John Cavanagh (NCSU Department of Biochemistry). TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
This project uses the reproductive organs of the nematode C, elegans as a model to understand how genes control animal development. The reproductive organs are generated from precursor cells that have the potential to generate all tissues of the adult organ. These precursor cells divide to generate cells that are further restricted in their potential until they finally differentiate into the mature tissues of the organ. Experiments conducted under this project provide evidence that precursor cells are critically dependent on the chromatin state. DNA is packaged into chromatin and this makes some genes more accessible than others. This result suggests that chromatin regulation may play a key role in the development of precursor cells. In this way precursor cells resemble stem cells, in that they can generate multiple cell types and they rely on chromatin regulation for their development. Therefore, research on C. elegans precursor cells might contribute to our understanding of stem cell biology.
Publications
- Kelleher, D. F., de Carvalho, C. E., Doty, A. V., Layton, M., Cheng, A. T., Mathies, L. D., et al. (2008). Comparative Genetics of Sex Determination: Masculinizing Mutations in Caenorhabditis briggsae. Genetics, 178(3), 1415-1429.
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Progress 10/01/06 to 09/30/07
Outputs
OUTPUTS: Activities on this project include the execution and analysis of experiments, mentoring and teaching, and the organization of research conferences. The research results were disseminated through oral and poster presentations at local, regional, and international conferences. 1. Execution and analysis of experiments. Research experiments were conducted with the support of a research specialist. Experiments conducted over the last year contributed to the completion of two specific aims of this project. 2. Mentoring and teaching. Two undergraduate students and one graduate student were mentored while contributing to the research described in this project. In addition, the research was incorporated into laboratory exercises for two courses: Honors Principles of Genetics and Genes and Development. These exercises introduced students to basic research in genetics and to C. elegans as a model organism. 3. Organization of research conferences. I served as a local organizer for the
Society for Developmental Biology Southeast Regional Meeting that was held in Chapel Hill, NC. 4. Dissemination of results. Oral presentations were given at East Carolina University School of Medicine, North Carolina State University School of Veterinary Medicine, and the Triangle Area Worm group. Posters were presented at the Society for Developmental Biology Southeast Regional Meeting and the16th International C. elegans meeting.
PARTICIPANTS: Laura Mathies (PI) was responsible for guiding the research activities of all members of the research group. Zigrida Smith provided technical support for the research, including the preparation of reagents, maintenance of laboratory equipment, and execution of experiments. Collaborators include Dr. Julie Ahringer (MRC, England), Dr. Eric Haag (University of Maryland), and Dr. Alex Deiters (NCSU Department of Chemistry). This project provided training and professional development for Edward Large (Ph.D. candidate), Michael Willoughby (undergraduate), and Diana Klompstra (undergraduate).
Impacts
The C. elegans reproductive organs are generated from precursor cells that have the potential to generate all tissues of the adult organ. These precursor cells divide to generate cells that are further restricted in their potential until they finally differentiate into the mature tissues of the organ. In this way, organ precursor cells serve as a paradigm for understanding how stem cells develop into a wide array of differentiated tissues. Experiments conducted under this project provide evidence that the development of organ precursors is critically dependent on regulation of the chromatin state. DNA is packaged into chromatin and this packaging makes some genes more accessible than others. This result suggests that chromatin regulation may play a key role in the development of other precursor cells, including stem cells, and it provides a direction for future research in stem cell biology.
Publications
- Welchman, D. P., Mathies, L.D., Ahringer, J. (2007) Similar requirements for CDC-42 and the PAR-3/PAR-6/PKC-3 complex in diverse cell types. Developmental Biology 305(1), 347-357.
- Large, E.E. and L.D. Mathies (2007). Chromatin Regulation and Sex Determination in C. elegans. Trends in Genetics, 23(7): 314-317.
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Progress 10/01/05 to 09/30/06
Outputs
Organogenesis involves the coordination of basic processes, including cell division, survival, and differentiation. These processes are essential to development of all animals and their deregulation can underlie cancer. Our research uses the Caenorhabditis elegans reproductive organs as a model to learn how these processes are regulated during organ formation. The reproductive organs form from a simple primordium consisting of two somatic gonadal precursors (SGPs) and two germline precursors. The SGPs undergo a stereotyped program of cell division, rearrangement, and differentiation to give rise to all somatic tissues of the adult organ. I have described three genes that affect early SGP development. 1) hnd-1 influences SGP survival and position within the primordium, 2) tra-1 controls SGP cell polarity and division, and 3) ehn-3 acts with hnd-1 to control SGP survival and tra-1 to control SGP division. hnd-1 and tra-1 encode conserved transcription factors that are
found in all animals; ehn-3 is part of a new gene family in C. elegans. Our research over the last year has focused on ehn-3 and tra-1 and their role(s) in early organ formation. Since ehn-3 is part of a new gene family, we determined the functions of the other C. elegans family members. This work revealed functional overlap between ehn-3 and its paralog R08E3.4. Ongoing experiments are aimed at defining the cellular and molecular nature of this overlap. This work will shed light on the function of these key regulators. To understand how tra-1 controls organ formation, we have taken a bioinformatics and functional genomics approach. Specifically, we defined candidate TRA-1 binding sites in the C. elegans genome and identified their flanking genes. We are in the process of assessing their function using RNAi. We also developed a novel strategy for tissue-specific RNAi. In the coming years, we will broaden our RNAi screen to include more genes and to incorporate our tissue-specific RNAi
strategy.
Impacts
By studying organogenesis in the model nematode C. elegans, researchers will learn the genetic controls of cell division and differentiation. This work has potential to impact the fields of cancer biology and stem cell biology. Since this project focuses on the reproductive organs, insights from this research might one day be applied to controlling plant and animal parasitic nematodes.
Publications
- No publications reported this period
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Progress 10/01/04 to 09/30/05
Outputs
Organogenesis involves the coordination of basic processes, including cell division, survival, and differentiation. These processes are essential to development of all animals and their deregulation can underlie cancer. Our research uses the Caenorhabditis elegans reproductive organs as a model to learn how these processes are regulated during organ formation. The reproductive organs form from a simple primordium consisting of two somatic gonadal precursors (SGPs) and two germline precursors. The SGPs undergo a stereotyped program of cell division, rearrangement, and differentiation to give rise to all somatic tissues of the adult organ. I have described three genes that affect early SGP development. 1) hnd-1 influences SGP survival and position within the primordium, 2) tra-1 controls SGP cell polarity and division, and 3) ehn-3 acts with hnd-1 to control SGP survival and tra-1 to control SGP division. hnd-1 and tra-1 encode conserved transcription factors that are
found in all animals; ehn-3 is part of a new gene family in C. elegans. Our research over the last year has continued to focus on ehn-3 and its role(s) in early organ formation. The ehn-3 locus produces multiple mRNAs, all of which are encode proteins with paired zinc fingers. As an essential first step toward defining the biochemical activity of EHN-3, we have assayed the biological activity of these isoforms. Since ehn-3 is part of a new gene family in C. elegans, we have begun to explore the function of the other family members. This work will clarify the developmental role of ehn-3, and it may also shed light on the evolution of gene families. Finally, we have conducted pilot genetic screens for enhancers of tra-1 and ehn-3. The ehn-3 enhancer screen identified at least one gene not previously known to control SGP development. Therefore, ehn-3 enhancer screens will be employed in the coming years to identify new genes controlling organ formation.
Impacts
By studying organogenesis in the model nematode C. elegans, researchers will learn general mechanisms of organ formation, which will contribute to an understanding of the causes of congenital organ defects. Since this project focuses on the reproductive organs, insights from this research might one day be applied to controlling plant and animal parasitic nematodes.
Publications
- No publications reported this period
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Progress 10/01/03 to 09/30/04
Outputs
Organogenesis involves the coordination of cellular processes that are essential to development more broadly, and are critical for organ function and often viability. Our research uses the C. elegans gonad as a model to address several basic questions in organogenesis. In particular, we hope to understand how the different tissues of the gonad are assembled into the primordial organ, how these tissues acquire a configuration typical of the organ, and how this organization impacts subsequent development. The gonad primordium consists of two somatic gonadal precursors (SGPs) and two germline precursors. Our work focuses on SGP development. The SGPs undergo a stereotyped series of cell divisions to give rise to all somatic tissues of the gonad. I previously described three genes that affect early SGP development. 1) HND-1 is a Hand bHLH transcription factor that influences SGP survival and SGP position within the primordium. 2) The sex determining gene, tra-1, controls
cell polarity and division of the SGPs in both sexes. TRA-1 is the C. elegans homolog of the Ci/GLI family of zinc-finger transcription factors that control embryonic patterning and cell division. 3) The ehn-3 gene acts redundantly with hnd-1 for SGP survival and with tra-1 for SGP division. The ehn-3 locus encodes related C2H2 zinc-finger proteins and is therefore likely to regulate gene transcription. Over the last year, the focus of our research has shifted from hnd-1 to ehn-3 for the following reasons: 1) The ehn-3 locus is more complex than previously recognized, warranting further molecular characterization, 2) ehn-3 is specifically expressed in the somatic gonad, whereas hnd-1 and tra-1 are expressed elsewhere, and 3) ehn-3 acts redundantly with both hnd-1 and tra-1; therefore, genetic screens for enhancers of ehn-3 can simultaneously identify genes controlling SGP survival and division. We now know that the ehn-3 locus produces multiple mRNAs, all of which are encode proteins
with paired zinc fingers. We have identified a new ehn-3 allele that is predicted to be a molecular null and are currently characterizing the new allele phenotypically. Genetic screens for ehn-3 enhancers are underway and have identified at least one new mutation. We are testing the idea that EHN-3 is a transcriptional regulator by searching for genes that are regulated by ehn-3 and determining if EHN-3 binds DNA. Defining the EHN-3 binding site will provide insight into its function and might reveal the molecular basis for its genetic interactions with hnd-1 and tra-1. This information could also be used to search for additional genes regulated by ehn-3, which will advance our understanding of how ehn-3 controls the processes of cell survival and division.
Impacts
By studying organogenesis in the model nematode C. elegans, researchers will learn general mechanisms of organ formation. This knowledge is expected to contribute to an understanding of the causes of congenital organ defects. Because this project focuses on the reproductive organs, insights from this research might one day be applied to controlling fecundity in plant and animal parasitic nematodes.
Publications
- Mathies, L.D., Schvarzstein, M., Morphy, K.M., Blelloch, R., Spence, A.M. and Kimble, J. 2004 tra-1/GLI controls development of somatic gonadal precursors in C. elegans. Development 131: 4333-4343.
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Progress 05/13/03 to 09/30/03
Outputs
Organogenesis involves the coordination of cellular processes that are essential to development more broadly, and are critical for organ function and often viability. Our research uses the C. elegans gonad as a model to address several basic questions in organogenesis. In particular, we hope to understand how the different tissues of the gonad are assembled into the primordial organ, how these tissues acquire a configuration typical of the organ, how this organization impacts subsequent development, and how organ shape is modulated in the two sexes. Previously, we identified three genes, hnd-1 and two ehn genes, required for early aspects of gonadogenesis: cell survival and cell position. hnd-1 encodes a Hand family bHLH protein, and ehn-3 encodes a protein with two paired Zn fingers; ehn-1 remains uncloned. Based on sequence similarity, hnd-1 and ehn-3 are likely to regulate gene transcription. This project centers on hnd-1 and its relationship with two ehn genes at
genetic and molecular levels and consists of three long-term objectives: (1) identify and characterize the ehn-1 locus, (2) explore the physical interactions among early gonadal regulators, and (3) identify new regulators of early gonadogenesis. During the last six months, work was initiated on all three objectives. Using an in vitro assay, we discovered a physical interaction between the sex-determining protein, TRA-1, and the Zn finger protein, EHN-3. We will attempt to confirm this interaction in vivo over the next year. In addition, we have significantly augmented our panel of bacterially expressed proteins for further biochemical studies and have developed inbred strains for rapidly mapping mutations isolated in our genetic screens. Fine genetic mapping of ehn-1 and genetic screens to identify new regulators of gonadogenesis are currently underway.
Impacts
Nematodes are among the world's most significant parasites, affecting humans, cultivated crops, and domesticated animals. Our studies of the reproductive system in the model nematode Caenorhabditis elegans hold hope of revealing ways to control fecundity in parasitic nematodes. In addition, organogenesis involves processes important for normal development. Through studies of basic developmental processes in model organisms, we will undoubtedly advance our understanding of human health issues including cancer and birth defects.
Publications
- Chang, W., Tilmann, C., Thoemke, K., Markussen, F.-H., Mathies, L. D., Kimble, J., and Zarkower, D. 2004. A forkhead protein controls sexual identity of the C. elegans male somatic gonad. Development, in press.
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