Horse Genetics, 3rd Edition

Completely updated and revised, the third edition of this essential textbook describes the basic genetics of the horse including coat colour, parentage, medical and population genetics, cytogenetics, performance, breeding systems and genetic conservation, as well as the many recent advances in genomics. New for the third edition: - More information on genomics and biology have been included - There are two additional chapters on genetics with respect to infectious diseases and reproduction - Expanded sections on quantitative genetics and genomic selection provide comprehensive coverage - Many new figures further illustrate key points in the text - Redesigned in colour throughout and keeping the popular features of previous editions This authoritative text remains one of the key sources of information for basic genetic principles and their specific applications to the horse, and is essential for students of equine studies, animal breeding and veterinary science, as well as horse breeders and owners. Cover......Page 1 Horse Genetics......Page 4 Copyright......Page 5 Contents......Page 6 Preface to the First Edition......Page 8 Preface to the Second Edition......Page 10 Preface to the Third Edition......Page 12 1 Nature of Horse Breeds......Page 14 Genetic Relationships Among Breeds......Page 17 Website......Page 19 Climate, environment and evolution......Page 20 Domestication of horses......Page 23 Archeological evidence for domestication of horses......Page 24 Which horse species was first domesticated?......Page 25 Genomic Data on Horse Evolution and Domestication......Page 26 References......Page 27 Species classification and population standings......Page 29 Chromosomal differences among the Equidae species......Page 30 Endangered species......Page 32 Horses......Page 33 Asiatic Wild Asses......Page 34 Zebras......Page 36 Rare fertility in mules and hinnies......Page 38 References......Page 39 What Are Genes?......Page 42 DNA replication......Page 43 Genetic code......Page 44 Identification of genetic variation at the DNA level for horses......Page 45 Effect of amino acid substitutions......Page 46 Other roles of DNA: introns and exons, and regulatory DNA sequences......Page 48 Nucleotide substitution changing an amino acid......Page 49 Genes in the nucleus......Page 50 Genes in mitochondria......Page 51 Meiosis......Page 52 The inheritance of gender......Page 53 References......Page 54 Genotypes: Homozygous and Heterozygous......Page 55 Breeding heterozygous and homozygous horses......Page 56 Schematic representation of pedigrees......Page 58 Practices for the Naming of Genes......Page 59 Nomenclature for ambiguous genotypes......Page 60 Partial dominance among alleles......Page 61 Expected ratios, statistical tests and alternative models......Page 62 Epistasis and Hypostasis......Page 63 Epigenetics......Page 64 Environmentally induced epigenetic changes......Page 65 Parent of origin effects......Page 66 Determination of Inheritance Patterns......Page 67 Summary......Page 68 References......Page 69 Genome Projects......Page 70 The sequencing of Twilight’s genome......Page 71 Non-coding DNA/RNA......Page 72 Sex Chromosomes......Page 73 Whole genome sequencing and why we have reference genomes......Page 74 Genome-wide Association Studies (GWAS)......Page 75 DNA transcription......Page 76 Chromatin and epigenetic markers......Page 77 Summary......Page 78 References......Page 79 Websites......Page 81 General Comments about Coat Color Genetics......Page 82 Extension Locus......Page 83 Trait inheritance and gene symbol......Page 84 Gene function......Page 85 Trait inheritance and gene symbol......Page 86 Gene function......Page 88 References......Page 89 Cream Dilution Locus......Page 91 Trait inheritance and gene symbol......Page 93 Genetics of CR and cr in bay, chestnut, and black horses......Page 94 Molecular genetics and gene location......Page 95 Breeds......Page 96 Trait inheritance and gene symbol......Page 97 Gene action......Page 99 Silver Dilution Locus......Page 100 Trait inheritance and gene symbol......Page 101 Gene function......Page 102 Champagne Dilution Locus......Page 103 Molecular genetics and gene location......Page 104 References......Page 105 Tobiano Locus......Page 107 Combination with colors and other patterns......Page 108 Trait inheritance and gene symbol......Page 109 Dominant White Locus......Page 110 Homozygous lethal white......Page 113 Sabino ( SB1) Locus......Page 114 Trait inheritance and gene symbol......Page 115 Roan Locus......Page 116 Trait inheritance and gene symbol......Page 117 Roan phenocopy: rabicano......Page 118 Summary......Page 119 References......Page 120 Website......Page 121 Frame Overo Locus......Page 122 Molecular genetics and gene location......Page 124 Health concerns......Page 125 Splashed White Loci......Page 126 Trait inheritance and gene symbol......Page 127 Molecular genetics and gene location......Page 129 Breeds......Page 130 References......Page 131 Trait Inheritance and gene symbol......Page 133 Molecular genetics and gene location for LP......Page 135 Modifying Genes for LP......Page 136 Health concerns......Page 137 References......Page 138 The gray trait......Page 139 Trait inheritance and gene symbol......Page 140 Molecular genetics and gene location......Page 142 Health concerns......Page 143 Genetics of Brindle......Page 144 Genetics of Curly......Page 145 References......Page 146 13 Putting it All Together: Color by Design......Page 148 References......Page 152 Two rules of parentage testing......Page 153 DNA Tests......Page 154 Microsatellite DNA markers......Page 155 International Collaboration and Oversight of Horse Parentage Testing......Page 156 Example of a Parentage Case Using Microsatellite DNA Markers......Page 157 Special cases......Page 158 References......Page 160 Websites......Page 161 15 Blood Groups and Neonatal Isoerythrolysis......Page 162 References......Page 164 16 Medical Genetics......Page 166 Partially dominant disease variant with some desirable effects......Page 168 Dominant disease genes only apparent under some management conditions......Page 169 Phenocopies: same disease phenotype can be caused by variants in different genes......Page 170 Other Mendelian diseases......Page 172 Genome-wide association studies......Page 173 Complex hereditary diseases: to what extent does genetics influence phenotype?......Page 174 Examples of QTL studies......Page 175 Database of Horse Diseases: OMIA......Page 176 References......Page 177 Website......Page 180 The standard horse karyotype......Page 181 Cytogenetics and Genomics......Page 182 Identification of chromosomes in a karyotype......Page 183 Chromosome polymorphisms not associated with disease......Page 185 Fertility problems associated with autosome rearrangements......Page 186 Loss of the X chromosome......Page 187 Disorders of Sexual Development (DSD)......Page 188 Prevalence of Chromosome Abnormalities Among Horses......Page 189 References......Page 190 Marker Assisted Selection......Page 194 Major Gene for Racing Distance: MSTN......Page 195 Major Gene for Gait: DMRT3......Page 197 Summary for Major Genes......Page 198 References......Page 199 Measuring Variation......Page 201 Nature of Heritability......Page 202 The Effect of Selection on Heritability Scores......Page 203 Heritability estimates for racing......Page 204 Heritability of other horse traits......Page 205 Estimated Breeding Values (EBV) for Performance Traits......Page 206 Best linear unbiased prediction (BLUP)......Page 207 References......Page 208 Establishing Pedigrees......Page 210 Estimates of relatedness and “percentage of blood”......Page 211 Evaluation of pedigree influences......Page 212 Toward homozygosity......Page 214 Closed stud books......Page 215 Outcrossing......Page 216 Tail-female lineage, strain breeding and families......Page 217 Questioning Breeding Myths in the Light of Genetics......Page 218 References......Page 219 Microbiome......Page 221 Are mitochondria descended from bacteria?......Page 224 Maternal inheritance of mitochondria......Page 225 Mitochondria and performance......Page 226 References......Page 227 Genetics of Resistance and Susceptibility to Infectious Diseases......Page 229 Inbreeding and Diversity in Horse Breeds......Page 230 Summary......Page 231 Index......Page 232 Back Cover......Page 242 "Completely updated and revised, the third edition of this essential textbook describes the basic genetics of the horse including coat colour, parentage, medical and population genetics, cytogenetics, performance, breeding systems and genetic conservation, as well as the many recent advances in genomics"-- Provided by publisher