Publication Date

2018-05-02

Document Type

Honors Project

Degree Name

Bachelor of Arts

Department

Neuroscience

Advisors

Michael J.F. Barresi

Keywords

Development, Teratogenesis, Pharyngeal system, Craniofacial, Neurobiology, Environment, Crude oil, Pollutants, Face-Abnormalities, Skull-Abnormalities, Pharynx-Abnormalities, Polycyclic aromatic hydrocarbons-Physiological effect, Pollution-Physiological effect, Teratogenic agents

Abstract

Polycyclic aromatic hydrocarbons (PAH’s) such as Naphthalene (naph), are hazardous compounds which can be found at high concentrations in fossil fuel pollutants and everyday consumables alike. To study how environmental teratogens such as PAHs can intersect and interfere with embryonic development, we have taken advantage of the extrauterine development of the utilized zebrafish model system. We aimed to identify the cellular and molecular processes that mediate PAH teratogenesis of the craniofacial system. The craniofacial skeleton is derived in part from cranial neural crest cells (NCCs) which migrate through transient structures known as the pharyngeal pouches and arches. We postulated that naph could be targeting its effect on three possible cell types: the cranial NCCs, cells of the developing pharyngeal pouches, or epibranchial placodal cells that are known to interact with pouch and arch growth. Using antibody and transgenic reporters for both arches and pouches, we demonstrate that naph causes specific malformations in the posterior most region of the pharyngeal system. Our data supports a model in which PAH mediated teratogenesis shows early molecular disruption of key genetic markers followed by later morphological defects. Additionally, early changes in arch markers such as dlx2a suggest a potential model in which PAH’s first target the posterior pharyngeal arches followed by an indirect impact on pouch endoderm development and potentially epibranchial placodes. We are currently assessing the involvement of the Aryl hydrocarbon receptor pathway as potentially mediating these teratogenic events.

Rights

2018 Emilie Suzanne Jones

Language

English

Comments

87 pages : illustrations (chiefly color) Includes bibliographical references (pages 80-87)

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