Kenneth Wallace
Assistant Professor
Department of Biology
165 Science Center
Clarkson University
PO Box 5805
Potsdam, NY 13699-5805
E-mail: kwallace@clarkson.edu
Phone: 315-268-4498
Fax: 315-268-7118
Education
Ph.D., Ohio State University- Molecular Genetics (1998)
Courses Taught
- BY350 Comparative Anatomy
- BY352 Vertebrate Anatomy Lab
- BY310 Developmental Biology
- BY160 Cell and Molecular Biology
- BY162 Cell and Molecular Biology Lab
- BY300 Advances in Biology Research
Research Interests
Development of the vertebrate digestive system using zebrafish as a model system. I am focusing on development of the enteric neurons and smooth muscle layers that surround the intestine. I am investigating molecular pathways involved in development of these cell types.
Vertebrate digestive development
My research is focused on development of the digestive system using the zebrafish as a model organism. Zebrafish embryogenesis occurs over the course of five days in an externally developing transparent embryo. At the end of embryogenesis, all of the major vertebrate organs are represented. These attributes make zebrafish an excellent organism to study the development of the digestive system.
Specifically I am investigating aspects of enteric nervous system development. Digestive tract development has been conserved across a number of vertebrates. Innervation of the smooth muscle by enteric neurons is a process that has many molecular and mechanistic features in common among different vertebrate species. During vertebrate embryogenesis, neural crest cells migrate from the vagal region of the neural tube to enter the anterior portion of the digestive tract. As the crest cells migrate to the rostral end of the intestine they proliferate and differentiate forming the enteric nervous system. The enteric nervous system is unique in that the neural precursors need to expand rather than be selectively eliminated as in other areas of the peripheral nervous system.
As with other vertebrates, zebrafish vagal neural crest cells migrate to the anterior digestive system and begin to migrate in a rostral direction. Migration along the intestine occurs in two lateral streams encompassing most the second day of embryogenesis. Later steps of zebrafish enteric precursor proliferation and differentiation have not been well defined. I have begun to address these topics of later enteric development once the precursors have migrated to the digestive system as well as formation of the smooth muscle that the neurons will innervate.
My research focuses on both the molecular aspects of migration, proliferation, and axon pathfinding as the enteric precursors migrate through the zebrafish digestive tract, differentiate, and innervate the intestinal smooth muscle. In order to identify critical signaling pathways and transcription factors involved in these processes, I am using two digestive mutants flotte latte (flo) and slimjim (slj) which have defects in intestinal smooth muscle as well as enteric nervous system cell number, distribution, and projection.
To investigate these topics, I am using molecular biology techniques, histology, immunohistochemistry, RNA in situ hybridization, and antisense technology to knock down gene function in developing embryos. Each of these techniques is powerful tools to identify molecular pathways involved in enteric neural development.
Publications (last 5 years)
K.N. Wallace, A.C. Dolan, C. Seiler, E.M. Smith, S. Yusuff, L. Chaille-Arnold, B. Judson, C. Yengo, H.L. Sweeney, M. Pack, "Mutation of smooth muscle Myosin causes epithelial invasion and cystic expansion of the zebrafish intestine," Developmental Cell., 8(5): 717-726 2005.
K.N. Wallace, S. Akhter, E.M. Smith, K. Lorent, and M. Pack, "Intestinal growth and differentiation in zebrafish," Mechanisms of Development, 122: 157-173 2005.
K.N. Wallace, and M. Pack, "Unique and conserved aspects of gut development in zebrafish," Developmental Biology, 255(1): 12-29 2003.
Undergraduates in Lab
2007: Tasha Olden (2008), Mandi Lee (2007), Sarah Beckman (2007), Will Gundling (2009), Andrea Knapp (2008)
2006: Tasha Olden (2008), Mandi Lee (2007), Sarah Beckman (2007), Jessica Terrell (2009)
2005: Julie A. Choiniere (Biology), Nicolas J. Frazee (Biomolecular Science), Molly J. Malone (Biology)
2004: Marielle Blackburn (Biology), Molly J. Malone (Biology)