JENNIFER OSTROM LIANG, PHD
Assistant Professor of Biology
Research Interests
Dr. Liang's research focuses on how secreted signaling molecules affect cell fate in the vertebrate embryo. Genetic and cellular techniques have been used in zebrafish to explore the role of the signaling protein Cyclops (embryos that lack the Cyclops gene have only one eye). They found an early role for Cyclops in specifying the floor plate, a row of cells in the ventral neural tube essential for patterning motor neurons and guiding axon outgrowth. Later in development, Cyclops is expressed in the left side of the brain, in a region that will give rise to the pineal organ. Although morphological and functional asymmetries are widespread in vertebrate brains, this was one of the first opportunities to study how a signaling pathway influences brain laterality. In zebrafish and other teleost fish, the photoreceptive pineal organ is an important regulator of circadian rhythm and develops in a complex with a unilateral, left-sided parapineal organ.  In mutants that lack asymmetric Cyclops signaling in the brain, the pineal organ is often displaced from its normal medial-to-left position and parapineal sidedness is randomized. Despite its altered laterality, circadian rhythm in the pineal complex is intact. This demonstrates that Nodal/Cyclops functions to regulate laterality, but not function of the pineal complex. Future work will focus on two problems. First, she has begun genetic and molecular screens to identify signaling pathways that control morphogenesis and function of the pineal and parapineal organs. An important tool in these screens is a transgenic zebrafish line that expresses the green fluorescent protein in the developing pineal organ. Second, she plans to understand how signaling molecules induce the cellular changes needed to generate a differentiated tissue.
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