Awards and Honors:

- Women in Science Scholar (Elsevier Foundation), 2006
- NIH Pathway to Independence Award (K99/R00), 2006-2011

In vitro explantation and 2.5 hour culture of chick embryo dorsal neural folds (containing the premigratory neural crest) that have been electroporated in vivo with cadherin6B morpholino (red) and subsequently stained for phalloidin (green) and DAPI (blue). Cadherin6B knock-down results in premature neural crest cell emigration and migration of cells away from the explanted neural fold (top left). This phenotype is demonstrated by phalloidin staining which shows the presence of extended actin-filled processes prominent in emigrating and migrating neural crest cells leaving the explanted neural fold. Image taken from Coles E.G., Taneyhill L.A., Bronner-Fraser M. (2007). A critical role for Cadherin6B in regulating avian neural crest emigration. Dev Biol, Article in Press.

Research:

Functional roles of Wnt and Snail2 Target Genes in the Neural Crest

The neural crest
The Taneyhill lab studies the vertebrate neural crest, a transient population of migratory cells that ultimately differentiate to become a wide range of structures, including the peripheral nervous system, pigment cells (melanocytes), and the bones and cartilage of the face and neck. Consequently, many human congenital and hereditary malformations (craniofacial abnormalities, heart defects), diseases (Hirschprung) and cancers result from aberrant neural crest development. Neural crest cells detach from the neural tube and migrate away into the periphery by undergoing an epithelial-to-mesenchymal transition (EMT) characterized by the loss of various epithelial properties (for example, cell-cell adhesion) and the subsequent acquisition of a mesenchymal (motile) phenotype, an event molecularly similar to EMTs observed in metastatic or invasive cancers when cells leave the primary tumor site.

Our lab is studying neural crest formation in the avian (chicken) embryo to better understand overall animal growth and development. The chicken provides an excellent model system for understanding neural crest development for a number of reasons: 1) The embryo is large and develops externally, making it amenable to both in ovo (in the egg) and in vitro manipulations; 2) the availability of the genomic sequence allows us to do molecular biology and biochemistry-based assays; and 3) the wealth of descriptive literature detailing neural crest development gives a rich history upon which we can draw for our studies. Thus, the chicken is the ideal organism in which to study the neural crest and elucidate how abnormalities in neural crest development give rise to various diseases, disorders and cancers. To address these effects on health and proper development, we must first ask some general questions about neural crest formation. How do these cells arise in the dorsal neural tube, and what distinguishes them from the rest of the neural tube? What molecular cues transform these non-motile precursors (the premigratory neural crest) to migratory neural crest cells? Collectively, we aim to understand the functional role of Wnt signaling, and genes regulated by Wnt, during this process.

Identification of Wnt target genes in the neural crest
The secreted Wnt protein family is known to function in cell fate specification, including neural crest development. But what genes does Wnt signaling regulate in the neural crest? What is/are the molecular mechanism(s) underlying this regulation? Taking advantage of a Wnt-induced gene expression profile in the neural crest obtained from a microarray screen, our lab is exploring how these genes function during avian neural crest development. Current experiments are aimed at determining the functional role of these genes in the induction, migration and differentiation of the neural crest, as well as elucidating the molecular mechanism(s) by which Wnt signaling regulates gene expression. We use a combination of molecular biology (quantitative PCR - QPCR, generation of expression constructs) and embryological (electroporation of DNA or oligonucleotides, in situ hybridization, cell injections, placement of protein-coated beads) approaches to address these questions.

The Wnt target Snail2 and neural crest EMT/emigration
Because of the known role of Snail transcriptional repressors in both neural crest development and tumor cell EMT, our lab is examining the function of Snail2 (formally called Slug) during neural crest EMT and emigration of cells from the dorsal neural tube. What genes does Snail2 target and repress during neural crest EMT? Are there distinct molecular similarities (or differences) between neural crest EMT and tumor cell EMT? One example of this is the direct transcriptional repression of the cell adhesion molecule cadherin6B (Cad6B) by Snail2 during neural crest EMT, mediated by the binding of Snail2 to E boxes (Snail2 binding sites) in the Cad6B regulatory region. Interestingly, the molecular mechanism of this regulation is analogous to that seen when Snail1 represses transcription of another cadherin, E-cadherin, during tumor cell EMT. Using molecular biology (QPCR), embryological (electroporation, in situ hybridization), and biochemical (chromatin immunoprecipitation - ChIP, gel shifts - EMSAs, luciferase assays) techniques, we are investigating the function of Cad6B, and other genes regulated by Snail2, in neural crest EMT.

Selected/Representative Publications: PUBMED Links.

E. G. Coles, L. A. Taneyhill, and M. Bronner-Fraser. 2007. A critical role for Cadherin6B in regulating avian neural crest emigration. Dev Biol 312: 533-544.

L. A. Taneyhill, E. G. Coles, and M. Bronner-Fraser. 2007. Snail2 directly represses cadherin6B during epithelial-to-mesenchymal transitions of the neural crest. Development 134: 1481-1490.

L. A. Taneyhill and M. Bronner-Fraser. 2005. Recycling signals in the neural crest. J Biol 4: 10.1-10.4.

L. A. Taneyhill and M. Bronner-Fraser. 2005. Dynamic alterations in gene expression after Wnt-mediated induction of avian neural crest. Mol Biol Cell 16: 5283-5293.

L. A. Taneyhill. 2005. Understanding embryonic development: from screens to genes. Genome Biol 6: 359-361.

L. A. Taneyhill and D. Pennica. 2004. Identification of Wnt responsive genes using a murine mammary epithelial cell line model system. BMC Dev Biol 4: 6.

L.A. Taneyhill and Adams MS. 2008. Investigating Regulatory Factors and their DNA Binding Affinities Through Real Time Quantitative PCR (RT-QPCR) and Chromatin Immunoprecipitation (ChIP) Assays. In: Methods in Cell Biology, Avian Embryology, 2nd Edition. Eds. M Bronner-Fraser, L Wilson, PT Matsudaira. Elsevier, Inc.

Current/Active/Supplemental Grants:

Title: Functional Roles of Wnt and Snail2 Target Genes
Source: Elsevier Scholars (Women in Science) Foundation
Amount: $10,000

Title: Functional Roles of Wnt and Snail2 Target Genes in Neural Crest Development
Source: NIH Pathway to Independence Award (R00), NICHD
Amount: $747,000

Title: UMD GRB Summer Research Award 2008

DEPARTMENT OF ANIMAL AND AVIAN SCIENCES
COLLEGE OF AGRICULTURE AND NATURAL RESOURCES
UNIVERSITY OF MARYLAND, COLLEGE PARK

POSITION ANNOUNCEMENT

POSITION:
Faculty Research Assistant
Full-time, 12-month position

POSITION DESCRIPTION:
A position is available immediately for a Faculty Research Assistant to contribute to our multidisciplinary studies aimed at elucidating the molecular basis of avian neural crest development. The Faculty Research Assistant will help in the training of undergraduate and graduate students and take part in the management of the laboratory of Dr. Lisa Taneyhill. Laboratory skills should include the ability to perform various molecular biology and biochemical assays, such as recombinant DNA/cloning; DNA, RNA, and protein blotting; immunohistochemistry; and in situ hybridization. Experience with microscopy and spectroscopy, chick embryology and tissue culture are also highly desirable. Other duties may include in vitro and in vivo protein binding assays, the maintenance of established cell lines, and microdissection of chick embryos. Additional responsibilities will consist of the ordering of supplies and reagents, maintenance of purchasing records, and general upkeep of laboratory equipment.

A Bachelor's degree in a related field and prior laboratory research experience is essential, and an advanced degree (Research Masters) in Developmental, Molecular and/or Cell Biology is preferred. Fluency in spoken and written English is required. Candidates must be U.S. citizens or permanent residents.

Salaries are highly competitive, negotiable and commensurate with qualifications. Fringe benefits offered.

Send cover letter (including a brief description of previous research experience), CV/ resume, and the name and contact information of 3 references to:

Dr. Lisa Taneyhill
Department of Animal and Avian Sciences
1405 Animal Sciences Center
University of Maryland
College Park, MD 20742.

Email: ltaney@umd.edu

Candidates are strongly encouraged to submit applications by email. Please indicate in the subject line that you are applying for the position as Faculty Research Assistant in Dr. Taneyhill's laboratory.

Applications will be accepted until December 15th, or until a suitable candidate is identified.