| Title |
Fascin1-Dependent filopodia guide directional collective neural crest migration |
| Publication Type |
dissertation |
| School or College |
School of Medicine |
| Department |
Oncological Sciences |
| Author |
Boer, Elena F |
| Date |
2015-08 |
| Description |
Directional collective cell migration underlies diverse normal and pathological processes, including embryonic development, wound healing and cancer metastasis. Migrating cells are highly adaptable and can switch between modes of migration in response to changes in physical, molecular or chemical signals. To maintain directional collective migration, integration and communication of guidance cues must occur in a precise and regulated manner. The cellular structures and/or molecules that mediate cell-cell communication and oversee directional collective migration are not well characterized. Filopodia are dynamic cellular protrusions that function as antennae on migrating cells. We hypothesized that filopodia mediate cell-cell communication to promote directional collective cell migration. To address this, we analyzed directional collective migration of neural crest (NC) cells in a zebrafish mutant for fascin1a (fscn1a MZ), which encodes an actin-bundling protein required for filopodia formation. Although filopodia were severely disrupted in fscn1a MZ embryos, most NC streams were competent for directional collective cell migration. In a subset of fscn1a MZ embryos, abnormal development of NC-derived craniofacial cartilage and peripheral neurons was concomitant with defective directional collective migration of selective cranial NC streams. These phenotypes were enhanced by disruption of Cxcr4a/Cxcl12b chemokine signaling, demonstrating that fscn1a and cxcr4a/cxcl12b function redundantly during NC migration. Our findings suggest that fscn1a MZ represents a sensitized genetic background to uncover redundancies that regulate directional collective migration. Knockdown of Fscn1a in zebrafish embryos using an antisense morpholino oligonucleotide (MO) could provide a rapid alternative approach to identify additional redundant mechanisms of directional collective migration. MOs are a widely used knockdown reagent for analysis of gene function during embryonic development; however, many MOs cause off-target cell death phenotypes. For this reason, comparison of MO-induced (morphant) phenotypes to a null genetic mutant is essential to validate a MO and determine the optimal dose. We characterized a Fscn1a translation blocking MO (fscn1aMO) and found that disruption of NC cell filopodia was similar in fscn1a morphants and fscn1a MZ mutants. However, fscn1aMO caused severe off-target defects in NC migration and derivative development. Our results provide an example of MO-induced off-target phenotypes and support the idea that MOs should be used only when validated. |
| Type |
Text |
| Publisher |
University of Utah |
| Subject MESH |
Neural Crest; Zebrafish; Drosophila; Cell Movement; Cell Communication; Signal Transduction; Genes, Homeobox; Cell Adhesion Molecules, Neuronal; Oligonucleotides, Antisense; Morpholinos; Morphogenesis; Body Patterning; Microfilament Proteins; Gene Expression Regulation, Developmental; Epithelial-Mesenchymal Transition |
| Dissertation Institution |
University of Utah |
| Dissertation Name |
Doctor of Philosophy |
| Language |
eng |
| Relation is Version of |
Digital version of Fascin1-Dependent Filopodia Guide Directional Collective Neural Crest Migration |
| Rights Management |
© Elena F. Boer |
| Format |
application/pdf |
| Format Medium |
application/pdf |
| Format Extent |
127,944,249 bytes |
| Source |
Original in Marriott Library Special Collections |
| ARK |
ark:/87278/s6nk7m0c |
| Setname |
ir_etd |
| ID |
1355118 |
| Reference URL |
https://collections.lib.utah.edu/ark:/87278/s6nk7m0c |
