Genetic pathways that promote cell-survival during development are poorly defined, yet represent potential targets for anti-cancer drugs. The genes that promote survival of melanocytes, in particular those that operate independently of the well-characterized anti-apoptotic pathway headed by the receptor tyrosine kinase, C-kit, are largely unknown. Through forward and reverse genetic studies in zebrafish, we have identified two genes that regulate the number of embryonic melanocytes independently of C-kit. One is Touchtone (Tct), which appears to prevent necrotic cell death in melanocytes, but whose molecular identity is unknown. The other is transcription factor AP-2alpha, which has long been known to be expressed in neural crest, but whose function there has remained obscure because of redundancy. Interestingly we have evidence that Tct and AP-2 are also required within neural crest-derived Rohon-Beard sensory neurons (RBs). Our overall hypothesis is that Tct and AP-2 regulate survival of neural crest derivatives, and that they may do so as part of a single regulatory pathway.
In Aim 1, to gain insight into the possibly novel Tct pathway, we propose to identify the Tct gene by positional cloning and identify new alleles.
In Aim 2, to learn the function of AP-2-type activity in neural crest and melanocytes, we propose temporal and spatial modulation of AP-2-type activity with cell-type-specific promoters.
In Aim 3, to determine the function of Tct and AP-2 in RBs, we propose ultrastructural analysis of RBs in the Tct mutant, and temporal and spatial modulation of AP-2-type activity with RB-specific promoters. Finally we propose to test for possible interaction of Tct and AP-2 type activity with double mutant experiments. These experiments exploit the advantages of the zebrafish model to dissect poorly understood neural crest regulatory pathways. These pathways are potential entry points for therapies against malignant melanoma and other neural crest diseases.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
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Development - 1 Study Section (DEV)
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Haynes, Susan R
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University of Iowa
Anatomy/Cell Biology
Schools of Medicine
Iowa City
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Decker, Amanda R; McNeill, Matthew S; Lambert, Aaron M et al. (2014) Abnormal differentiation of dopaminergic neurons in zebrafish trpm7 mutant larvae impairs development of the motor pattern. Dev Biol 386:428-39
Dougherty, Max; Kamel, George; Grimaldi, Michael et al. (2013) Distinct requirements for wnt9a and irf6 in extension and integration mechanisms during zebrafish palate morphogenesis. Development 140:76-81
de la Garza, Gabriel; Schleiffarth, Jack Robert; Dunnwald, Martine et al. (2013) Interferon regulatory factor 6 promotes differentiation of the periderm by activating expression of Grainyhead-like 3. J Invest Dermatol 133:68-77
Nakano, Yoko; Jahan, Israt; Bonde, Gregory et al. (2012) A mutation in the Srrm4 gene causes alternative splicing defects and deafness in the Bronx waltzer mouse. PLoS Genet 8:e1002966
Van Otterloo, Eric; Li, Wei; Garnett, Aaron et al. (2012) Novel Tfap2-mediated control of soxE expression facilitated the evolutionary emergence of the neural crest. Development 139:720-30
Cornell, Robert A (2011) Investigations of the in vivo requirements of transient receptor potential ion channels using frog and zebrafish model systems. Adv Exp Med Biol 704:341-57
Van Otterloo, Eric; Li, Wei; Bonde, Gregory et al. (2010) Differentiation of zebrafish melanophores depends on transcription factors AP2 alpha and AP2 epsilon. PLoS Genet 6:e1001122
Kwon, Hye-Joo; Bhat, Neha; Sweet, Elly M et al. (2010) Identification of early requirements for preplacodal ectoderm and sensory organ development. PLoS Genet 6:e1001133
Sabel, Jaime L; d'Alençon, Claudia; O'Brien, Erin K et al. (2009) Maternal Interferon Regulatory Factor 6 is required for the differentiation of primary superficial epithelia in Danio and Xenopus embryos. Dev Biol 325:249-62
Cornell, Robert A; Aarts, Michelle; Bautista, Diana et al. (2008) A double TRPtych: six views of transient receptor potential channels in disease and health. J Neurosci 28:11778-84

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