Preface vii
Acknowledgments ix
Statement regarding the use of pictures x
Statement regarding nomenclature xii
PART I INTRODUCTION TO THE PIGMENTARY SYSTEM 1
1 Introduction to the Pigmentary System 3
1.1 Introduction 3
1.2 Colors of vertebrate animals 4
1.3 Other pigment cells 12
1.4 The epidermal melanin unit 12
1.5 Mammalian hair 13
1.6 Melanosome biogenesis and translocation 14
1.7 Melanin 15
1.8 Hair growth 15
1.9 Hair growth cycles 17
1.10 Embryonic development of the pigment cell lineage 18
1.11 Pigment cells in culture 18
1.12 Conclusion 19
Appendix: color loci of the mouse 20
PART II THE PIGMENTARY LOCI 49
2 Introduction to Mutant Pigmentary Genes 51
2.1 Defects of normal melanocyte development: white spotting and graying with age 51
2.2 Defects in normal melanosome development: albinism 52
2.3 Transport of melanosomes to other cells: the 'dilute' phenotype 53
2.4 Pigment-type switching: from eumelanogenesis to pheomelanogenesis 54
3 White Spotting and Progressive Graying 57
3.1 Definitions and general background 58
3.2 Pigment-cell development: developmental biology 62
3.3 Cellular signaling pathways for melanocytes 71
3.4 Pigment phenotypes and the classical white-spotting genes 88
3.5 The head, heart, ears, and eyes 127
4 'Albinism' and the Failure of Normal Melanosome Development 132
4.1 Background 133
4.2 The melanosomal matrix 140
4.3 The enzymes that catalyze melanogenesis 146
4.4 Membrane proteins that regulate the internal milieu of the melanosome 153
4.5 Protein processing and routing to the maturing melanosome 156
4.6 Melanosome transport 171
5 Pigment-Type Switching 177
5.1 Introduction 178
5.2 Yellow phenotypes 184
5.3 Melanin pigment 189
5.4 Melanogenesis and the eumelanin/pheomelanin switch mechanism 190
5.5 Signaling the switch mechanism at the cellular level 192
5.6 Yellow genes 194
PART III TECHNOLOGY AND RESOURCES 207
6 Novel Mouse Pigmentary Mutants Generated by
Genetic Manipulation 209
6.1 Introduction 209
6.2 Mouse transgenesis: generation of genetically engineered mice 210
6.3 Coat-color transgenic mice 219
6.4 The coat-color mutants generated by gene targeting 224
6.5 Influence of the genetic background 229
6.6 Conclusions 230
7 Other Species and Other Resources 232
7.1 Introduction 232
7.2 Resources 233
7.3 Other species 235
References 243
Index 286
