Presentations
Oral Presentations
Guest Speaker. "Graduate Teaching Skills." Post baccalaureate Research Education Program (PREP). University of New Mexico. Albuquerque, NM. December 14, 2015.
Guest Speaker. "Paradise Outbreak Scenario-biologist." Problems in Public Health, Center for Global Health, Dept. of Community Health, Boonshoft School of Medicine, Wright State University. Dayton, OH. July 30, 2014.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of RA signaling to promote pharyngeal muscle at the expense of ventricular cardiomyocytes in zebrafish. Heart Institute Research Retreat. Cincinnati, OH. September 9, 2013. 1st Place Trainee Presentation
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of RA signaling to promote pharyngeal muscle at the expense of ventricular cardiomyocytes in zebrafish. Molecular and Developmental Biology Graduate Student Symposium. Cincinnati, OH. August 22, 2013.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of retinoic acid signaling to restrict heart chamber size in zebrafish. Molecular and Developmental Biology Graduate Student Symposium. Cincinnati, OH. September 20, 2011.
Poster Presentations
Dohn, TE, Cripps, RM. Mrtf has an early SRF-independent role in adult muscle development. 58th Annual Drosophila Research Conference. San Diego, CA. March 29 - April 2, 2017.
Dohn, TE, Cripps, RM. Actin isoforms in Drosophila muscle function. The Allied Genetics Conference. Orlando, FL. July 13-17, 2016.
Dohn, TE, Ravisanka, P, Barske, LA, Crump, JG, Waxman, JS. Nr2f proteins act downstream of RA signaling to restrict ventricular cardiomyocytes in zebrafish. Weinstein Cardiovascular Conference. Durham, NC. May 19-21, 2016.
Dohn, TE, Waxman, JS. Nr2f1a acts downstream of RA signaling to Promote Pharyngeal Muscle at the Expense of Ventricular Cardiomyocytes in zebrafish. Molecular and Developmental Biology Graduate Student Symposium. Cincinnati, OH. August 21, 2014.
Dohn, TE, Waxman, JS. Nr2f1a acts downstream of RA signaling to Promote Pharyngeal Muscle at the Expense of Ventricular Cardiomyocytes in zebrafish. Society for Developmental Biology 73rd Annual Meeting. Seattle, WA. July 17-20, 2014.
Dohn, TE, Waxman, JS. Nr2f1a acts downstream of RA signaling to Promote Pharyngeal Muscle at the Expense of Ventricular Cardiomyocytes in zebrafish. 11th International Conference on Zebrafish Development and Genetics. Madison, WI. June 24-28, 2014.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of RA signaling to restrict ventricular cell number in zebrafish. 1st Annual KOI Zebrafish Meeting. Cincinnati, OH. March 7, 2014.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of RA signaling to restrict ventricular cell number in zebrafish. 51st Annual Midwest Society for Developmental Biology Conference. Saint Louis, MO. September 26, 2013.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of RA signaling to restrict ventricular cell number in zebrafish. Weinstein Cardiovascular Conference. Tuscon, AZ. May 18, 2013.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of RA signaling to predominantly restrict ventricular cell number in zebrafish. Heart Institute Research Retreat. Cincinnati, OH. September 24, 2012. 1st Place Graduate Poster.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of RA signaling to predominantly restrict ventricular cell number in zebrafish. Molecular and Developmental Biology Graduate Student Symposium. Cincinnati, OH. August 23, 2012.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of RA signaling to predominantly restrict ventricular cell number in zebrafish. 10th International Conference on Zebrafish Development and Genetics. Madison, WI. June 20, 2012.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of RA signaling to predominantly restrict ventricular cell number in zebrafish. Society for Developmental Biology Midwest. Cincinnati, OH. May 11, 2012.
Dohn, TE, Waxman, JS. Distinct phases of Wnt/ß-catenin signaling direct cardiomyocyte formation in zebrafish. Weinstein Cardiovascular Conference. Chicago, IL. May 5, 2012.
Dohn, TE, Waxman, JS. Distinct phases of Wnt/ß-catenin signaling direct cardiomyocyte formation in zebrafish. Heart Institute Research Retreat. Cincinnati, OH. September 12, 2011.
Dohn, TE, Waxman, JS. Distinct phases of Wnt/ß-catenin signaling direct cardiomyocyte formation in zebrafish. Society for Developmental Biology 70th Annual Meeting. Chicago, IL. July 24, 2011.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of retinoic acid signaling to restrict heart chamber size in zebrafish. University of Cincinnati College of Medicine Graduate Student Research Forum. Poster. Cincinnati, OH. 2011.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of retinoic acid signaling to restrict heart chamber size in zebrafish. Molecular and Developmental Biology Graduate Student Symposium. Cincinnati, OH. 2010.
Dohn, T., McWhorter, M. Role of Plexins in the development of motor neurons in zebrafish. The Ohio Journal of Science. Springfield, OH. 2009.
Dohn, TE; Tiggelaar, JM. Distribution of rocky intertidal zone gastropods Nerita versicolor and N. peloronta in sun and shade microhabitats on San Salvador, The Bahamas. The Ohio Journal of Science. 2007.
Guest Speaker. "Graduate Teaching Skills." Post baccalaureate Research Education Program (PREP). University of New Mexico. Albuquerque, NM. December 14, 2015.
Guest Speaker. "Paradise Outbreak Scenario-biologist." Problems in Public Health, Center for Global Health, Dept. of Community Health, Boonshoft School of Medicine, Wright State University. Dayton, OH. July 30, 2014.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of RA signaling to promote pharyngeal muscle at the expense of ventricular cardiomyocytes in zebrafish. Heart Institute Research Retreat. Cincinnati, OH. September 9, 2013. 1st Place Trainee Presentation
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of RA signaling to promote pharyngeal muscle at the expense of ventricular cardiomyocytes in zebrafish. Molecular and Developmental Biology Graduate Student Symposium. Cincinnati, OH. August 22, 2013.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of retinoic acid signaling to restrict heart chamber size in zebrafish. Molecular and Developmental Biology Graduate Student Symposium. Cincinnati, OH. September 20, 2011.
Poster Presentations
Dohn, TE, Cripps, RM. Mrtf has an early SRF-independent role in adult muscle development. 58th Annual Drosophila Research Conference. San Diego, CA. March 29 - April 2, 2017.
Dohn, TE, Cripps, RM. Actin isoforms in Drosophila muscle function. The Allied Genetics Conference. Orlando, FL. July 13-17, 2016.
Dohn, TE, Ravisanka, P, Barske, LA, Crump, JG, Waxman, JS. Nr2f proteins act downstream of RA signaling to restrict ventricular cardiomyocytes in zebrafish. Weinstein Cardiovascular Conference. Durham, NC. May 19-21, 2016.
Dohn, TE, Waxman, JS. Nr2f1a acts downstream of RA signaling to Promote Pharyngeal Muscle at the Expense of Ventricular Cardiomyocytes in zebrafish. Molecular and Developmental Biology Graduate Student Symposium. Cincinnati, OH. August 21, 2014.
Dohn, TE, Waxman, JS. Nr2f1a acts downstream of RA signaling to Promote Pharyngeal Muscle at the Expense of Ventricular Cardiomyocytes in zebrafish. Society for Developmental Biology 73rd Annual Meeting. Seattle, WA. July 17-20, 2014.
Dohn, TE, Waxman, JS. Nr2f1a acts downstream of RA signaling to Promote Pharyngeal Muscle at the Expense of Ventricular Cardiomyocytes in zebrafish. 11th International Conference on Zebrafish Development and Genetics. Madison, WI. June 24-28, 2014.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of RA signaling to restrict ventricular cell number in zebrafish. 1st Annual KOI Zebrafish Meeting. Cincinnati, OH. March 7, 2014.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of RA signaling to restrict ventricular cell number in zebrafish. 51st Annual Midwest Society for Developmental Biology Conference. Saint Louis, MO. September 26, 2013.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of RA signaling to restrict ventricular cell number in zebrafish. Weinstein Cardiovascular Conference. Tuscon, AZ. May 18, 2013.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of RA signaling to predominantly restrict ventricular cell number in zebrafish. Heart Institute Research Retreat. Cincinnati, OH. September 24, 2012. 1st Place Graduate Poster.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of RA signaling to predominantly restrict ventricular cell number in zebrafish. Molecular and Developmental Biology Graduate Student Symposium. Cincinnati, OH. August 23, 2012.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of RA signaling to predominantly restrict ventricular cell number in zebrafish. 10th International Conference on Zebrafish Development and Genetics. Madison, WI. June 20, 2012.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of RA signaling to predominantly restrict ventricular cell number in zebrafish. Society for Developmental Biology Midwest. Cincinnati, OH. May 11, 2012.
Dohn, TE, Waxman, JS. Distinct phases of Wnt/ß-catenin signaling direct cardiomyocyte formation in zebrafish. Weinstein Cardiovascular Conference. Chicago, IL. May 5, 2012.
Dohn, TE, Waxman, JS. Distinct phases of Wnt/ß-catenin signaling direct cardiomyocyte formation in zebrafish. Heart Institute Research Retreat. Cincinnati, OH. September 12, 2011.
Dohn, TE, Waxman, JS. Distinct phases of Wnt/ß-catenin signaling direct cardiomyocyte formation in zebrafish. Society for Developmental Biology 70th Annual Meeting. Chicago, IL. July 24, 2011.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of retinoic acid signaling to restrict heart chamber size in zebrafish. University of Cincinnati College of Medicine Graduate Student Research Forum. Poster. Cincinnati, OH. 2011.
Dohn, TE, Waxman, JS. Coup-tf1a acts downstream of retinoic acid signaling to restrict heart chamber size in zebrafish. Molecular and Developmental Biology Graduate Student Symposium. Cincinnati, OH. 2010.
Dohn, T., McWhorter, M. Role of Plexins in the development of motor neurons in zebrafish. The Ohio Journal of Science. Springfield, OH. 2009.
Dohn, TE; Tiggelaar, JM. Distribution of rocky intertidal zone gastropods Nerita versicolor and N. peloronta in sun and shade microhabitats on San Salvador, The Bahamas. The Ohio Journal of Science. 2007.
Student presentations
Wilson, DL, Dohn, TE, Cripps, RM. The role of miR-31b in the adult muscle formation of Drosophila melanogaster. 59th Annual Drosophila Research Conference. Poster presentation. Philadelphia, PA. April 11-15, 2018.
Wilson, DL, Dohn, TE, Cripps, RM. The role of miR-31b in the adult muscle formation of Drosophila melanogaster. Department of Biochemistry & Molecular Biology Research Day. Oral presentation. University of New Mexico. Albuquerque, NM. April 18, 2018. Awarded Magna Cum Laude and Robert B. Loftfield Award.
Paudel, Praveen; Dohn, Tracy PhD; and Cripps, Richard, D.Phil., “Myocardin Related Transcription Factor (MRTF) constitutively active and dominant negative line analysis”, Poster presentation at UNM Biology Research Day, Albuquerque, New Mexico, 2018
Wilson, DL, Dohn, TE, Cripps, RM. Muscle formation in Drosophila melanogaster is influenced by miR-31b and miR-987. Department of Biology 27th Annual Research Day. Oral presentation. University of New Mexico. Albuquerque, NM. March 22-23, 2018. Awarded first place undergraduate oral presentation.
Wilson, DL, Dohn, TE, Cripps, RM. Muscle formation in Drosophila melanogaster is influenced by miR-31b and miR-987. New Mexico Legislators Meeting. Poster presentation. La Fonda Hotel, Santa Fe, NM. January 29th, 2018.
Paudel, Praveen; Dohn, Tracy PhD; and Cripps, Richard, D.Phil., “Myocardin Related Transcription Factor (MRTF) constitutively active and dominant negative line analysis”, Poster presentation at SACNAS, Salt Lake City, Utah, 2017
Paudel, Praveen; Dohn, Tracy PhD; and Cripps, Richard, D.Phil., “Myocardin Related Transcription Factor (MRTF) constitutively active and dominant negative line analysis”, Poster presentation at UNM Biology Research Day, Albuquerque, New Mexico, 2017
Wilson, DL, Dohn, TE, Cripps, RM. Analysis of four miRNAs in the muscle development of Drosophila melanogaster. Department of Biology 26th Annual Research Day. Poster presentation. University of New Mexico. Albuquerque, NM. March 30-31, 2017. Awarded first place undergraduate poster presentation.
Wilson, DL, Dohn, TE, Cripps, RM. The role of miR-31b in the adult muscle formation of Drosophila melanogaster. Department of Biochemistry & Molecular Biology Research Day. Oral presentation. University of New Mexico. Albuquerque, NM. April 18, 2018. Awarded Magna Cum Laude and Robert B. Loftfield Award.
Paudel, Praveen; Dohn, Tracy PhD; and Cripps, Richard, D.Phil., “Myocardin Related Transcription Factor (MRTF) constitutively active and dominant negative line analysis”, Poster presentation at UNM Biology Research Day, Albuquerque, New Mexico, 2018
Wilson, DL, Dohn, TE, Cripps, RM. Muscle formation in Drosophila melanogaster is influenced by miR-31b and miR-987. Department of Biology 27th Annual Research Day. Oral presentation. University of New Mexico. Albuquerque, NM. March 22-23, 2018. Awarded first place undergraduate oral presentation.
Wilson, DL, Dohn, TE, Cripps, RM. Muscle formation in Drosophila melanogaster is influenced by miR-31b and miR-987. New Mexico Legislators Meeting. Poster presentation. La Fonda Hotel, Santa Fe, NM. January 29th, 2018.
Paudel, Praveen; Dohn, Tracy PhD; and Cripps, Richard, D.Phil., “Myocardin Related Transcription Factor (MRTF) constitutively active and dominant negative line analysis”, Poster presentation at SACNAS, Salt Lake City, Utah, 2017
Paudel, Praveen; Dohn, Tracy PhD; and Cripps, Richard, D.Phil., “Myocardin Related Transcription Factor (MRTF) constitutively active and dominant negative line analysis”, Poster presentation at UNM Biology Research Day, Albuquerque, New Mexico, 2017
Wilson, DL, Dohn, TE, Cripps, RM. Analysis of four miRNAs in the muscle development of Drosophila melanogaster. Department of Biology 26th Annual Research Day. Poster presentation. University of New Mexico. Albuquerque, NM. March 30-31, 2017. Awarded first place undergraduate poster presentation.
Abstracts
Coup-tf1a Acts Downstream of RA Signaling to Promote Pharyngeal Muscle at the Expense of Ventricular Cardiomyocytes in Zebrafish
Cardiovascular congenital malformations affect about 1% of live births, necessitating a better understanding of the mechanisms of cardiovascular development. Retinoic acid (RA) signaling must be precisely controlled for proper cardiac development in vertebrates. RA signaling limits both atrial and ventricular cardiomyocyte (CM) specification, but the mechanisms underlying cardiac progenitor restriction are not yet understood. In a screen for RA responsive genes, we found that coup-tf1a is an RA responsive gene expressed in the lateral plate mesoderm (LPM) in zebrafish. Coup-tf1a deficient embryos exhibit enlarged hearts similar to what is observed in RA signaling deficient embryos. Interestingly, coup-tf1a deficiency leads to an increase predominantly in first heart field ventricular CMs (VCs), supporting the hypothesis that atrial and ventricular cells are restricted by separate mechanisms downstream of RA signaling. We performed fate-mapping experiments and found that a posterior expansion of the VP field is the origin of the surplus VCs in the embryo. To determine if there are neighboring mesodermal derivatives lost from the same region of the anterior LPM, we also examined the fates of pharyngeal endothelial and muscle progenitors. In coup-tf1a deficient embryos, we found that there was a decrease in pharyngeal muscles that was similar to RA signaling deficient embryos, while pharyngeal endothelial cells of the great arches were not affected. Together, our data are the first to suggest that within the anterior lateral plate mesoderm RA signaling acts through a Coup-tf protein to promote pharyngeal muscle progenitor specification at the expense of first heart field VPs.
Distinct phases of Wnt/ß-catenin signaling direct cardiomyocyte formation in zebrafish
Normal heart formation requires distinct phases of canonical Wnt/b-catenin (Wnt) signaling. Understanding the mechanisms by which Wnt signaling drives correct cardiac formation in vivo is critical for understanding the formation of the heart as well as essential to studies developing stem cells into cardiomyocytes (CM) in vitro. Here, we investigate the roles of Wnt signaling using heat-shock inducible transgenes which allow us to increase or decrease Wnt signaling in the embryo. During the first 24 hours of development, we find three distinct phases during which Wnt signaling modulates CM formation. Wnt signaling has previously been implicated in mesoderm specification as well as regulating the pre-cardiac mesoderm, however, we have identified a later role during CM proliferation in which Wnt signaling is necessary and sufficient to promote the differentiation of atrial cells. This study also extends the previous studies on Wnt signaling during mesoderm specification and in the pre-cardiac mesoderm. Interestingly, we define a new role for Wnt signaling in the pre-cardiac mesoderm in which Wnt is sufficient to prevent cardiac cell differentiation leading to cell death as opposed to the previously proposed roles in inhibition of cardiac progenitor specification. Together with an even later role of Wnt signaling in restricting the proliferation of differentiating ventricular CMs, our results indicate that there are four distinct phases of Wnt signaling during the first 3 days of zebrafish development that allow for the proper formation of the heart.
Coup-tf1a works as a downstream effector of RA signaling to limit cardiac cell specification in zebrafish
Retinoic acid (RA) signaling regulates numerous processes during vertebrate development. Recently, RA signaling has been found to restrict heart size, however, downstream effectors of RA signaling involved in this process are not well understood. In a screen for RA target genes involved in restricting cardiac cell number, coup-tf1a was identified as a candidate effector gene. In order to determine if coup-tf1a is required to limit heart size, we used morpholinos (MOs) to affect coup-tf1a expression in zebrafish embryos. We find that coup-tf1a morphants (MO injected embryos) have enlarged hearts similar to RA signaling deficient embryos. Furthermore, morphants show increases in the cells expressing cardiac marker genes and cardiac cell number. Interestingly, the ventricular cells are more sensitive to loss of coup-tf1a resulting in a more dramatic increase in cell number relative to the atrial cells. This makes coup-tf1a the first gene shown to be primarily required to restrict ventricular cell number. Therefore, our data suggest that coup-tf1a acts downstream of RA signaling to allow for the proper allocation of cardiac cells. Together with recent data on hoxb5b, which has been shown to specifically restrict atrial cell number, these data suggest a model where coup-tf1a may work with hoxb5b, or other RA downstream effectors, to restrict the size of the heart of a developing vertebrate embryo.
Cardiovascular congenital malformations affect about 1% of live births, necessitating a better understanding of the mechanisms of cardiovascular development. Retinoic acid (RA) signaling must be precisely controlled for proper cardiac development in vertebrates. RA signaling limits both atrial and ventricular cardiomyocyte (CM) specification, but the mechanisms underlying cardiac progenitor restriction are not yet understood. In a screen for RA responsive genes, we found that coup-tf1a is an RA responsive gene expressed in the lateral plate mesoderm (LPM) in zebrafish. Coup-tf1a deficient embryos exhibit enlarged hearts similar to what is observed in RA signaling deficient embryos. Interestingly, coup-tf1a deficiency leads to an increase predominantly in first heart field ventricular CMs (VCs), supporting the hypothesis that atrial and ventricular cells are restricted by separate mechanisms downstream of RA signaling. We performed fate-mapping experiments and found that a posterior expansion of the VP field is the origin of the surplus VCs in the embryo. To determine if there are neighboring mesodermal derivatives lost from the same region of the anterior LPM, we also examined the fates of pharyngeal endothelial and muscle progenitors. In coup-tf1a deficient embryos, we found that there was a decrease in pharyngeal muscles that was similar to RA signaling deficient embryos, while pharyngeal endothelial cells of the great arches were not affected. Together, our data are the first to suggest that within the anterior lateral plate mesoderm RA signaling acts through a Coup-tf protein to promote pharyngeal muscle progenitor specification at the expense of first heart field VPs.
Distinct phases of Wnt/ß-catenin signaling direct cardiomyocyte formation in zebrafish
Normal heart formation requires distinct phases of canonical Wnt/b-catenin (Wnt) signaling. Understanding the mechanisms by which Wnt signaling drives correct cardiac formation in vivo is critical for understanding the formation of the heart as well as essential to studies developing stem cells into cardiomyocytes (CM) in vitro. Here, we investigate the roles of Wnt signaling using heat-shock inducible transgenes which allow us to increase or decrease Wnt signaling in the embryo. During the first 24 hours of development, we find three distinct phases during which Wnt signaling modulates CM formation. Wnt signaling has previously been implicated in mesoderm specification as well as regulating the pre-cardiac mesoderm, however, we have identified a later role during CM proliferation in which Wnt signaling is necessary and sufficient to promote the differentiation of atrial cells. This study also extends the previous studies on Wnt signaling during mesoderm specification and in the pre-cardiac mesoderm. Interestingly, we define a new role for Wnt signaling in the pre-cardiac mesoderm in which Wnt is sufficient to prevent cardiac cell differentiation leading to cell death as opposed to the previously proposed roles in inhibition of cardiac progenitor specification. Together with an even later role of Wnt signaling in restricting the proliferation of differentiating ventricular CMs, our results indicate that there are four distinct phases of Wnt signaling during the first 3 days of zebrafish development that allow for the proper formation of the heart.
Coup-tf1a works as a downstream effector of RA signaling to limit cardiac cell specification in zebrafish
Retinoic acid (RA) signaling regulates numerous processes during vertebrate development. Recently, RA signaling has been found to restrict heart size, however, downstream effectors of RA signaling involved in this process are not well understood. In a screen for RA target genes involved in restricting cardiac cell number, coup-tf1a was identified as a candidate effector gene. In order to determine if coup-tf1a is required to limit heart size, we used morpholinos (MOs) to affect coup-tf1a expression in zebrafish embryos. We find that coup-tf1a morphants (MO injected embryos) have enlarged hearts similar to RA signaling deficient embryos. Furthermore, morphants show increases in the cells expressing cardiac marker genes and cardiac cell number. Interestingly, the ventricular cells are more sensitive to loss of coup-tf1a resulting in a more dramatic increase in cell number relative to the atrial cells. This makes coup-tf1a the first gene shown to be primarily required to restrict ventricular cell number. Therefore, our data suggest that coup-tf1a acts downstream of RA signaling to allow for the proper allocation of cardiac cells. Together with recent data on hoxb5b, which has been shown to specifically restrict atrial cell number, these data suggest a model where coup-tf1a may work with hoxb5b, or other RA downstream effectors, to restrict the size of the heart of a developing vertebrate embryo.