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TitleMolecular Characterisation of Primary Wool Follicle Initiation in Merino Sheep
LanguageEnglish
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Total Pages198
Table of Contents
                            TITLE: Molecular Characterisation of Primary Wool Follicle Initiation in Merino Sheep
	Table of Contents
	Abstract
	Declaration
	Acknowledgements
	Abbreviations
	Dedication
Chapter One Introduction and Literature Review
Chapter Two General Materials and Methods
Chapter Three Foetal Skin Series and Histology
Chapter Four Quantitative PCR of Whole Skin
Chapter Five Laser Capture Microdissection of Foetal Sheep Skin
Chapter Six General Discussion
Appendices
	Appendix I: General Solutions, Buffers and Stains
	Appendix II: Primers
References
                        
Document Text Contents
Page 1

Molecular Characterisation of Primary Wool Follicle

Initiation in Merino Sheep

Page 2

iii

Table of Contents

Abstract ................................................................................................................................... ii

Declaration ............................................................................................................................ iv

Acknowledgements ................................................................................................................ v

Abbreviations ....................................................................................................................... vii

Chapter 1 Introduction and Literature Review ............................................................ 2

1.1 Introduction ........................................................................................................... 2

1.2 Structure and Development of the Wool Follicle ............................................... 4

1.2.1 Structure and Function of Mammalian Skin ............................................... 4

1.2.2 Wool Follicle Types ........................................................................................ 5

1.2.2.1 Primary Follicles ..................................................................................... 6

1.2.2.2 Secondary and Secondary-Derived Follicles ........................................ 6

1.2.2.3 Secondary to Primary Ratio (S/P ratio) ................................................ 8

1.2.3 Molecular Basis of Primary Follicle Neogenesis ......................................... 8

1.2.3.1 First Dermal Signal: Formation of the Epidermal Placode ................ 9

1.2.3.2 First Epidermal Signal: Formation of the Dermal Condensate........ 13

1.2.3.3 Down growth of the epidermal placode .............................................. 13

1.2.3.4 Formation of the dermal papilla .......................................................... 14

1.2.3.5 Formation of the Follicle Bulb ............................................................. 14

1.2.3.6 Inner Root Sheath (IRS) ....................................................................... 15

1.2.3.7 Outer Root Sheath (ORS) ..................................................................... 16

1.2.3.8 Follicle Accessory Structures ............................................................... 16

1.2.3.8.1 Sebaceous Gland .......................................................................... 16

Page 99

Chapter 4 Quantitative PCR of Whole Skin



83


of gestation for the SHH receptor PTCH1 was significant with a large increase in mRNA

levels observed towards the end of the time series (Figure 4-19). PTCH1 expression

increased gradually from day 47 to 57 and then increased by 57% by day 60, a further 36% by

day 63 and finally increased by 87% from days 63 to 68.

PATCHED-1

Day of Gestation

R
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la
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N

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rm

a
lis

e
d

E
xp

re
ss

io
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a a
ab

bc
c

d

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<0.0001



Figure 4-19_Relative expression of the sonic hedgehog receptor patched-1(PTCH1),
normalised to RAC1, RHOa and GAPDH (mean ± SEM; day 43 n=4, day 47-68 n=8)


There was no significant difference in the expression of patched-1 between the

midside and rump samples (Figure 4-20; p=0.267).

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Chapter 4 Quantitative PCR of Whole Skin



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Patched-1

Sample Site

R
e
la

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N

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Figure 4-20_Site differences in relative normalised expression of the sonic hedgehog
receptor patched-1 (mean ± SEM; n=30)


4.4.3.6 Gene Expression Correlations

The gene expression analysis software tool GenEx (MultiD Analyses, Sweden) was

used to perform cluster analysis on the normalised expression values (Figure 4-21). Cluster

analysis revealed correlations between the expression patterns of: (1) the TNF family

members EDAR and EDARADD and PTCH1, (2) the stem cells markers ALP and β1-integrin,

(3) the TNF ligand EDA and receptor XEDAR, and (4) the proliferation markers PCNA and

CYCB1 (Figure 4-21).

Page 197

References



181


Yim, S. H., Ward, J. M., Dragan, Y., Yamada, A., Scacheri, P. C., Kimura, S., and Gonzalez,

F. J. (2003). Microarray analysis using amplified mRNA from laser capture

microdissection of microscopic hepatocellular precancerous lesions and frozen

hepatocellular carcinomas reveals unique and consistent gene expression profiles.

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Young, S. S. Y., and Chapman, R. E. (1958). Fleece characters and ther influence on wool

production per unit area in skin of Merino sheep. Australian Journal of Agricultural

Research , 363-372.

Yuan, J., Yan, R., Kramer, A., Eckerdt, F., Roller, M., Kaufmann, M., and Strebhardt, K.

(2004). Cyclin B1 depletion inhibits proliferation and induces apoptosis in human

tumor cells. Oncogene , 5843-52.

Yue, Z., Jiang, T. X., Widelitz, R. B., and Chuong, C. M. (2005). Mapping Stem Cell Fate in

the Feather Follicle. Nature , 1026-1029.

Zhang, M., Brancaccio, A., Weiner, L., Missero, C., and Brissette, J. L. (2003). Ectodysplasin

regulates pattern formation in the mammalian hair coat. Genesis , 30-7.

Zhang, Y., Tomann, P., Andl, T., Gallant, N. M., Huelsken, J., Jerchow, B., Birchmeier, W.,

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C., Millar, S. E., and Schmidt-Ullrich, R. (2009). Reciprocal requirements for

EDA/EDAR/NF-kappaB and Wnt/beta-catenin signaling pathways in hair follicle

induction. Dev Cell , 49-61.

Zhu, Q., Tipoe, G. L., and White, F. H. (1999). Proliferative activity as detected by

immunostaining with Ki-67 and proliferating cell nuclear antigen in benign and

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malignant epithelial lesions of the human parotid gland. Anal Quant Cytol Histol ,

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Zwaka, T. P., and Thomson, J. A. (2005). Differentiation of human embryonic stem cells

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