Presenter : Charlotte Taylor
Major : Biology
Mentor : Judith Elsen
Poster 10
The enteric nervous system (ENS), the largest component of the peripheral nervous system, provides intrinsic innervation of the intestinal tract and modulates gut function. The ENS forms a complex network of different neuronal subtypes and glial cells. ENS progenitors originate in the hindbrain, migrate to the gut, migrate caudally along the gut in two parallel streams, and eventually encircle the gut. ENS progenitors express different marker genes, e.g. phox2b, sox10, and ret. Our goal is to take advantage of the zebrafish model to learn whether expression of these marker genes designates distinct ENS progenitor populations. We used a phox2b:GFP transgenic line that expresses in ENS progenitors and double fluorescent in situ hybridization to quantify progenitor marker gene expression and colocalization in GFP+ cells. Our analysis suggests that subpopulations of enteric progenitors are present during zebrafish ENS development. These subpopulations are characterized by the following marker combinations: phox2b/sox10/ret, phox2b/ret, and phox2b. Our data also suggest that phox2b and sox10 expression is consistent along the length of the gut and ret expression is higher caudally. Our next step is to conduct lineage tracing studies to learn if distinct ENS progenitor subpopulations give rise to different ENS cell types, by tracing the offspring of genetically labeled subpopulations of progenitors. Traditionally, the Supreme Court has deferred to the President in times of war; however, following 9/11 the Court took an active role in placing limits on the President’s unilateral pow- ers. The Court’s decisions in these cases were effective in restraining Executive power, but they only somewhat protected and restored the detainees’ civil liberties. The protection of certain individual rights has been followed by the curtailment of others. Currently, the Obama Administration is facing criticism for the indefinite detention of detainees, and this study provides a framework which outlines how civil liberties can again begin to be restored.