Meow A Genetic Concert for Cats

By Kerry Janet Fowler and Gracia Louise

Meow A Genetic Concert for Cats by Dr Kerry Fowler is an important book for cat breeders, owners, judges and veterinarians who are curious about the genetic makeup, DNA testing and diversity of pedigree cat breeds.

Peek inside, and find chapters, tables and a glossary describing what is scientifically known about the genes responsible for

• Language: English
• Publisher: Kerry Fowler
• Release date: Jun 7, 2017
• ISBN: 9780648121152

Kerry Janet Fowler

Dr. Kerry Fowler Grad Dip Ed MSc PhD is a fifth generation Fowler living in Williamstown, and a Homegrown author with the City of Hobson's Bay, Victoria, Australia. Archibald J Fowler The Rooster of Williamstown is her second book. Kerry has worked for 40 years in medical research and is an All Breeds Cat Judge. Her scientific training and cat judging experience throughout Australia and New Zealand equipped her to write her first book entitled, Meow A Genetic Concert for Cats, and to be a founding Trustee of the Feline Health Research Fund.

Book preview

Meow

A Genetic Concert for Cats

Meow

A Genetic Concert for Cats

Kerry J Fowler MSc PhD

Melbourne

Australia

© Kerry J Fowler 2017 All rights reserved

ISBN 978-0-646-97126-1 (Paperback)

ISBN 978-0-6481211-5-2 (EPUB)

ISBN 978-0-6481211-8-3 (MOBI)

Fowler, Kerry J

Meow A Genetic Concert for Cats

First edition, 2017

Reprinted, 2017, 2018, 2019, 2020 (revision)

Published by: KJ Fowler; PO Box 555, Williamstown, Victoria, Australia

Edited by: J Nevin; Baltimore, Maryland, US

Cover design and illustration by: G Haby and L Jennison; Melbourne, Victoria, Australia

Paperback printed by: Documents on Call; Footscray, Victoria, Australia

EPUB and MOBI design by: Thorpe-Bowker; Melbourne, Victoria, Australia

Disclaimer: This book is for educational and informational purposes based on the author’s views and interpretation of the published literature. Any errors are unintended. The content contained herein may not be suitable for every situation. Readers should seek professional advice where appropriate. Any references or web links to services do not constitute endorsement. Readers need to be aware that website references may have changed between when the book was written and when it is read.

Contents

Copyright

Preface and Acknowledgments

Chapter 1 Introduction

Old and new skills used by cat breeders

Chromosomes, genes, loci and alleles

Incomplete dominance and epistasis

Nomenclature

DNA and proteins

Types of mutations

DNA mutations

Endogenous retroviral elements

DNA regulatory elements

Copy number variation

Penetrance and gene expression

Epigenetics

X chromosome inactivation

Environment and diet

Chapter 2 The use of DNA sampling to study cats

Evolution and diversity of felid species and cat breeds

Challenges for cat breeders

Inbreeding

Genetic counselling

Genetic tests for feline health

Difficulties with interpreting results

Parentage testing

Introduced vs spontaneous mutation

Popular DNA tests for coat

Current limitations with interpreting common DNA test results

Examples of misclassifying cats based on minimal DNA testing

Terminology used for coat colour and pattern genes

Procedure for handling an unlikely DNA test result

DNA samples for research studies

Chapter 3 Coat colour

White cats and cats with white

Cats with white paws

White cats and deafness

White cats and blue eyes

Lessons from Foreign White cats

Variation in blue-eye colour

Eumelanin coat colour

Black, chocolate and cinnamon

Pheomelanin coat colour

Red and cream

Tortoiseshell

Amber, russet and copal

Dilute density gene

Dilute modifier gene

‘Dilute’ density genes identified in humans, mice and cats

Search for dilute modifier gene

Colour intensity

Full colour, sepia, colourpoint, mink, mocha and albino

Gene mining for silver inhibitor

Pseudo silver

Hypothetical recessive silver inhibitor gene

Chapter 4 Coat pattern, length and composition

Coat pattern

Agouti

Mackerel and classic tabby

Spotted tabby

Ticked tabby

Shaded and tipped

Gold glitter and bi-metal

Non-agouti and smoke

Ghost tabby markings

Tabby markings on non-agouti smoke adult cats

Tabby markings on non-agouti O gene adult cats

Lack of tabby markings on agouti O gene adult cats

Impact of DNA testing for agouti on judging categories

Charcoal pattern

Coat length

Longhair

Coat composition

Hairless, rex and wirehair

Chapter 5 Feline conformation and outcross breeding

Genetic tests for conformation

Folded and curled ears

Polydactyly

Short tails

Outcross breeding

Breeds with permitted outcross breeding programs

Selection of cats used for outcrossing

Continuous outcross breeding programs: pros and cons

Chapter 6 Conclusions

From genetic makeup to appearance

Role of the cat judge

Keeper of the standard

Limitations and subjectivity of breed standards

From phenotype to genotype

Wish list of future discoveries

DNA tests for coat colour, pattern and composition

DNA tests for conformation

Solving the Ragdoll cat mystery

Feline health

Last but not least

Glossary

References

About the Author

List of Tables

Table 1 Summary of popular DNA tests for coat colour, pattern or length

Table 2 Examples of actual and inferred genotypes for colour and pattern

Table 3 Examples of genes with multiple allelic mutations

Table 4 Summary of genes for white cats and cats with white

Table 5 Kitten varieties from initial program to generate Foreign White cats

Table 6 Summary of Extension gene mutations

Table 7 Summary of dense and dilute coat colours and genotypes

Table 8 Summary of dilute genes and phenotypes in humans, mice and cats

Table 9 Summary of Taqpep gene mutations in cats with classic tabby pattern

Table 10 Summary of FGF5 gene mutations that cause longhair in cats

Table 11 Summary of allele symbols for breeds with a change in coat composition

Table 12 Summary of ZRS mutations in cats with polydactyly

Table 13 Summary of T gene mutations in short-tailed cats

Table 14 Reduction of founder DNA in outcross breeding programs

List of Figures

Figure 1 Development of russet coat colour in Burmese kitten

Figure 2 DNA-verified non-agouti red tabby adult cat

Preface and Acknowledgments

This book reviews what scientists have discovered about the DNA basis of a number of genes and their adjacent regulatory elements that are responsible for feline diversity and appearance of cats. In addition, it summarizes the various scientific names and aliases for known genes and their alleles as well as their gene-encoded proteins that are responsible for a particular feline feature.

The book describes one of the major upshots of these genetic discoveries, namely the development of commercially available DNA tests. These DNA tests allow predictive testing for some of the challenges that breeders may face when breeding cats. These include avoiding specific health conditions, clarifying parentage and resolving some of the questionable coat colour and pattern phenotypes that are observed in cats.

Furthermore, the book introduces the reader to the rising scientific field of epigenetics, whereby environment and diet can chemically alter a gene’s ability to function. It describes some of the current limitations associated with interpreting DNA test results and posts a wish list of future DNA discoveries of which the DNA basis is presently unknown or unpublished. These traits include coat colours and patterns such as silver and ticked; coat compositions of particular breeds, for example, Peterbald; structural appearances, for example, short legs; and for diseases that may have a genetic predisposition.

Thus, this book provides a valuable adjunct for cat breeders to use whilst continuing to seek guidance from speaking with veterinarians, scientists and experienced breeders and studying registered pedigrees of prospective breeding cats. What’s more, it describes the role of show competition judges in assessing the quality of pedigree cats and kittens.

The author thanks judges, tutors, breed registrars, exhibitors, cat owners and DNA testing laboratory providers for engaging in and stimulating discussion about cats; scientists, veterinarians, breeders and supporters of feline research for their ongoing devotion to improving our cats; and Jeanne Nevin, a Baltimore, Maryland, US-based Norwegian Forest Cat exhibitor who spent many hours editing the manuscript and sharing her expertise in book design. My thanks also to Gracia Haby and Louise Jennison for their advice on publishing, and captivating cover design featuring a Siamese cat whose pattern was one of the first feline genes to be decoded. Also, thanks to Anita Cheetham, Rod Hitchmough, Bob and Nicki MacKenzie of New Zealand for sharing images of their cats and kittens; and to Dr Bronwyn Campbell, Dr Isobel Johnstone and Renate Leijen for valued comments. Finally, thank you to all the cats who have revealed themselves.

Chapter 1

Introduction

Old and new skills used by cat breeders

Since the first cat registry was set up in 1887 (1) (p. 243), breeders of pedigree cats have used a range of skills to improve the health, temperament and appearance of cats as well to establish new cat breeds. Not surprisingly, cat breeders have invested considerable resources working in the company of their cats, fellow breeders, veterinarians, scientists and cat show judges to achieve success, as measured by having their cats awarded at competitive cat shows as well as by breeding healthy, well-adjusted kittens that develop into fit, friendly cats; live to a ripe old age without requiring costly veterinary treatments for inherited conditions; and are in demand for companionship by repeat or referred pet buyers.

Reliably breeding high-quality pedigree cats requires a breeder to have skills in the choice of cats and kittens, hands-on cattery management, day-to-day decision making, long-term planning and the ability to allocate resources, such as time and money. More specifically, a breeder needs to research the known genetic problems in his or her chosen breed; to understand the characteristics of his or her individual cats, such as nutritional, welfare