Michael Harrington, Ph.D.


Biological Sciences 2009

Area of Doctoral Study: Biological Sciences
Undergraduate Institute: Benedict College

Research Advisor: Dr. Rachel Brewster

Current Position: Co-Founder/ CEO and Senior Scientist, Genoverde Biosciences, Inc.

Description of Research

Neural tube defects (NTD) arise when the neural tube, the precursor of the brain and spinal cord, fails to close properly during embryogenesis. On average, NTDs occur at a rate of 1 per 1000 pregnancies worldwide and are the second leading cause of malformations during pregnancies following congenital heart defects. Anencephaly results when the anterior neural tube fails to close properly while in more posterior regions, spina bifida results from incomplete closure. However the exact cause of these malformations and the mechanisms that govern proper neural tube morphogenesis are poorly understood.

In the zebrafish formation of the neural tube in anterior regions has been well characterized, while in posterior regions this process remains unclear.  In higher vertebrates, formation of the posterior neural tube occurs as a result of secondary neurulation. Unlike in anterior regions, which undergo primary neurulation, secondary neurulation involves the formation of the neural tube from a mesenchymal cell population originating from the tailbud. However in the zebrafish, posterior neural tube formation including the cellular behaviors exhibited during proper neural tube morphogenesis has not been characterized.

In this study, we describe posterior neural tube morphogenesis in the zebrafish. Several mutation in this model have been generated in which the posterior axis and neural tube is underdeveloped, yet how these mutations alter posterior development on a cellular level are unclear. Therefore, this study will serve as a foundation on which to assess current and future posterior neural tube defects/mutations in the zebrafish.