Shannon Fisher, M.D., Ph.D.

Assistant Professor, Departments of Medicine and Cell Biology and Anatomy
B.S., Purdue University, 1985
M.D., The Johns Hopkins University, 1993
Ph.D.,The Johns Hopkins University

Main Interests:

Human genetic diseases affecting the development and function of the skeleton represent a significant source of morbidity and mortality. However, they have also proven a rich source of biological information about the skeleton. My lab is taking a genetic approach to the study of skeletal development, using the zebrafish as a model system. The accessibility of the zebrafish embryo, and the ease of creating and screening for mutations, make it ideally suited for developmental genetics. There are four main areas of research in the lab: We have previously demonstrated a requirement during gastrulation for the activity of chordin, a negative regulator of BMP signaling, in proper patterning of the axial skeleton. We are using a combination of genetic and molecular biologic approaches to understand the molecular basis of chordin action, and of other modulators of BMP signaling, in skeletogenesis. We are carrying out single cell lineage studies to determine the origin of osteoblasts, the boneforming cells, in the embryo, and study factors that influence their development. We are screening, through X-rays of adult zebrafish, for new dominant and recessive mutations affecting the skeleton. Through this approach, we have isolated a zebrafish model for human Osteogenesis Imperfecta, a dominant skeletal dysplasia affecting the collagenous bone matrix. Through continued screening we aim to identify genes acting at all steps during the process of skeletogenesis, from initial patterning to differentiation and morphogenesis. We are developing new reagents and technologies for the study of skeletogenesis in the zebrafish. These include cloning marker genes to follow important cell populations during skeletal formation, and generating lines of transgenic fish expressing GFP in osteoblasts.

 Research Interests:

• Genetics of zebrafish skeletogenesis
• Modifiers of BMP signaling in early development
• Embryonic origin of osteoblasts

 Educational Activities:

• Preceptor, Predoctoral Training Program in Human Genetics
• Teaching in Priniciples of Development, first year medical school curriculum

Recognition and Leadership Roles:

• Member, Society for Developmental Biology
• Member, American Society of Human Genetics
• Member, Special Emphasis Review Panel, NHLBI
• Reviewer: Development, Developmental Biology, Mechanisms of Development 

 Publications:

• Fisher S, Grice EA, Vinton RM, Bessling SL and McCallion AS. (2006) Conservation of RET Regulatory Function from Human to Zebrafish Without Sequence Similarity. Science. 2006 Mar 23; [Epub ahead of print]
  
• Miller Bertoglio V, Fisher S, Sánchez A, Mullins M, Halpern ME: Differential regulation of chordinexpression in zebrafish mutants. Dev Biol 192: 537-550, 1997. Abstract
  
• Fisher S, Amacher S, Halpern ME: Loss of cerebum function ventralizes the zebrafish embryo.Development 124: 1301-1311, 1997. Abstract
  
• Fisher S, Halpern ME: Patterning the zebrafish axial skeleton requires early chordin function. Nature Genetics 23: 442-446, 1999. Abstract

Contact Information:

Shannon Fisher, MD, PhD

Johns Hopkins University School of Medicine
Institute of Genetic Medicine
Broadway Research Building
Baltimore, MD  21287

Phone: (410) 614-3337
Fax: (410) 955-7087
E-Mail:
sfisher@mail.jhmi.edu