Development of Planar Cell Polarity in the Mammalian Vestibular Sensory Organs Public
Etheredge, Jack Nixon (2011)
Published
Abstract
Abstract
Development of Planar Cell Polarity in the Mammalian Vestibular
Sensory
Organs
By Jack Nixon Etheredge
Epithelial planar cell polarity (PCP) refers to the coordinated
orientation of
neighboring cells, resulting in a polarity axis parallel to the
plane of the
epithelium. The vertebrate PCP pathway consists of a set of
membrane-
associated proteins, and primary cilia and their associated basal
bodies. The
underlying mechanism in vertebrate PCP signaling, however, has yet
to be
revealed. Each sensory hair cell of the inner ear contains a
polarized hair bundle
comprising an asymmetrically positioned primary cilium, the
kinocilium, and rows
of microvilli-derived stereocilia of graded height. Hair cells
within each inner ear
organ are oriented coordinately. In particular, the hair cells in
the saccule and
utricle show reverse polarity along a line of polarity reversal,
providing a unique
opportunity to dissect PCP signaling. To explore the mammalian
maculae as
PCP models, we established the timeline for cell proliferation,
differentiation, and
hair bundle formation in the mouse maculae. We further analyzed the
subcellular
localization of membrane associated PCP proteins, Vang-like 2
(Vangl2) and
Frizzled 3 (Fz3). We found asymmetric and polarized membrane
distribution of
Vangl2 and Fz3. Moreover, asymmetric distribution of both Fz3 and
Vangl2
precedes formation of stereocilia. Similar to published results of
another PCP
protein Pk2, confocal microscopy of embryonic day (E)18 mouse
embryos shows
that Vangl2, or Vangl2-GFP, and Fz3 appear to colocalize on one
side of the
boundary formed by a sensory hair cell and the adjacent non-sensory
supporting
cell in both maculae, independent of the orientation of the hair
cells. Adenoviral
transfection of eGFP-Vangl2 fusion protein in cultured utricles and
saccules
showed that Vangl2 can be enriched in both the hair cell and the
supporting cell
to the same boundary. These observations suggest that PCP proteins
are
distributed asymmetrically in both sensory hair cells and their
neighboring
supporting cells, and that the polarity of PCP proteins alone is
not sufficient to
determine the orientation of hair cells.
Table of Contents
Table of Contents
Chapter 1 General Introduction 1
Planar Cell Polarity 1
Intrinsic Cellular Polarity 2
Invertebrate PCP Signaling 2
Vertebrate PCP Signaling 4
Ciliary Genes and Relative Centriole Orientation in Vertebrate PCP
Regulation 5
Development of the Utricle and Saccule 6
Outstanding Issues in Vertebrate PCP Signaling 8
Chapter 2 Development of the utricular and saccular maculae of
mouse 14
Introduction 14
Results 15
The saccule and utricle grow in size and change shape during
development 15
Wildtype (WT) sensory hair cell morphology and development in mouse
utricle and saccule 15
WT intrinsic cell polarization and coordinated polarization occur
simultaneously 16
Discussion 16
Chapter 3 Vangl2 is asymmetrically localized in the utricle and
saccule 23
Introduction 23
Results 24
Vangl2 is asymmetrically localized in the utricle and saccule
24
Vangl2 is enriched along the medial side of hair cell membranes
between hair cells and supporting cells 24
Vangl2 is enriched along supporting cell membranes parallel to the
line of reversal 25
Vangl2 is enriched on the medial side of hair cell and supporting
cell membranes in single-cell labeling by viral transfection
25
Discussion 26
Chapter 4 Fzd3 is asymmetrically localized in the saccule and
utricle 34
Introduction 34
Results 34
Fzd3 is asymmetrically localized in both utricle and saccule.
34
Fzd3 colocalizes frequently with Vangl2-GFP on the apical membrane
of supporting cells and hair cells. 35
Fzd3 is enriched at the medial edges of hair cells across both
sides of the line of reversal in utricle and saccule 35
Discussion 36
Chapter 5 Overall Conclusions and Future Directions 41
Future directions 43
Chapter 6 Materials and Methods 46
Mouse Strains and animal care 46
Viral Transfection of Organ Culture 46
Whole mount analysis of inner ear tissues 46
Chapter 7 References 48
About this Master's Thesis
| School | |
|---|---|
| Department | |
| Degree | |
| Submission | |
| Language |
|
| Research Field | |
| Mot-clé | |
| Committee Chair / Thesis Advisor | |
| Committee Members |
Primary PDF
| Thumbnail | Title | Date Uploaded | Actions |
|---|---|---|---|
|
|
Development of Planar Cell Polarity in the Mammalian Vestibular Sensory Organs () | 2018-08-28 10:58:40 -0400 |
|
Supplemental Files
| Thumbnail | Title | Date Uploaded | Actions |
|---|