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Genetic analysis of primary cataract, persistent pupillary membrane and distichiasis and Gelatt, 1970; Walde, 1986, 1994; Whitley et al., 1995). CAT is defined as any opacity of the lens without other associated ocular diseases and systemic abnormalities (ECVO, 1998, 2004). Rubin (1989) described two different types of familial CAT in ECS. The first type, a cataracta corticalis posterior, occurs as a form with an early age of onset of one and a half to three years of age and a second form with a later age of onset, usually at eight to nine years of age. The second type, a cataracta nuclearis fibrillaris, appears in two year-old dogs (Rubin, 1989). By contrast Gelatt and MacKay (2005) distinguished between a congenital form of CAT and a later appearing form, mostly seen in four to seven year-old dogs. PPM describes remnants of the embryological vascular network which nourishes the anterior part of the developing lens and according to the ECVO usually regresses in the first weeks after birth. There can be: tiny, more or less triangular shaped dots, centrally, on the anterior capsule of the lens; retrocorneal, opaque brown/white material against the endothelium; strands from cornea to iris, from iris to iris, from iris to lens, connected to areas of dense white cataract; and strands connected to a sheet/ “spider web” of tissue in the anterior chamber (ECVO, 1998, 2004). Single or multiple hairs arising from the free eye lid margin (ECVO, 1998, 2004) are regarded as distichiasis. PRA is characterized by either primary photoreceptor dysplasia with an early onset or by primary photoreceptor degeneration with a late-onset (ECVO, 1998, 2004). Concerning the modes of inheritance of the above mentioned eye diseases, monogenic autosomal recessive inheritance (Barnett, 1978, 1980; Barnett and Startup, 1985; Gelatt, 1983a, 1983b; Whitley et al., 1995) or a mode of inheritance of a more complex nature (Olesen, 1974; Yakely, 1978) has been assumed for CAT in different dog breeds. In ECS, complex segregation analyses could show the significant contribution of many gene loci to CAT, DIST and PPM as well the exclusion of pure monogenic models for these eye diseases (Zadil, 2004). Monogenic autosomal dominant (Barnett, 1976; Whitley et al., 1995) or monogenic autosomal recessive inheritance (Wiesner and Willer, 1983) has been assumed for DIST and monogenic autosomal recessive inheritance (Black, 1972; Barnett, 1976; Chader, 1991; Peiffer and Gelatt, 1991; Rubin, 1989) has been assumed for PRA in the ECS. According to the ECVO (1998, 2004), PPM is not considered as hereditary in ECS, although a polygenic inheritance has been supposed (Veith and Gelatt, 1970; Strande et al., 1988) and confirmed by Zadil (2004). 30
Genetic analysis of primary cataract, persistent pupillary membrane and distichiasis Ophthalmological examinations have been compulsory for breeding dogs in the German kennel club for Spaniels (Jagdspaniel-Klub e.V., JSK) since 2001. Since 2004, the JSK recognizes only examinations for presumed inherited eye diseases (PIED) performed by veterinarians approved by the German panel of the European Eye Scheme for diagnosis of inherited eye diseases in animals, the Dortm<strong>und</strong>er Kreis (DOK, www.dok-vet.de). Dogs affected by CAT, congenital blindness, PRA, ectropion or entropion will be excluded from breeding in this kennel club. The offspring from dogs affected by PRA, CAT or congenital blindness are banned from further breeding as well. A certificate supplied by a DOK approved veterinarian stating that dogs intended to be mated within the next year are free from the above-mentioned eye diseases is required for breeding allowance. The objective of this study was to estimate genetic parameters for presumed inherited and prevalent eye diseases in the ECS bred in the JSK. CAT, PPM and DIST were included in the genetic analyses using liability models due to the involvement of a significant polygenic component in the mode of inheritance in ECS. In refined analyses, age at diagnosis of CAT was used for definition of two distinct traits, i.e. CAT diagnosed in up to three and a half year-old dogs (CAT-early) and CAT diagnosed in over three and a half year-old dogs (CATlate). The subdivision of CAT reported here was derived using different cut off ages for expression of CAT and genetic correlations among the different traits distinguished. The analysis of primary cataracts defined by age of diagnosis should allow us to distinguish between a single form of CAT with variable age of onset and genetically different age related forms of CAT. All analyses were performed separately for single-colored and multi-colored ECS. Materials and Methods The study was based on the results of ophthalmological examinations for PIED of 1232 ECS which were collected between January 2001 and July 2006 by the DOK. Dogs included in this analysis were born between 1981 and 2005. All ophthalmological examinations were performed by DOK-certified ophthalmologists using slit-lamp biomicroscopy and indirect ophthalmoscopy. These DOK-members were approved for examination of PIED after successful completion of a two-year training program. Eye examinations were performed according to the standardized protocol of the European College of Veterinary 31
Page 4 and 5: Bibliografische Informationen der D
Page 6 and 7: Wissenschaftliche Betreuung: Prof.
Page 9 and 10: Contents Chapter 1 Introduction …
Page 11 and 12: Introduction CHAPTER 1 Introduction
Page 13 and 14: Introduction Hannover. Chapter 2 re
Page 15 and 16: Review of canine primary cataract C
Page 17 and 18: Review of canine primary cataract 1
Page 19 and 20: Review of canine primary cataract p
Page 21 and 22: Review of canine primary cataract (
Page 23 and 24: Review of canine primary cataract R
Page 25 and 26: Review of canine primary cataract E
Page 27 and 28: Review of canine primary cataract K
Page 29 and 30: Review of canine primary cataract S
Page 31 and 32: Review of canine primary cataract T
Page 33 and 34: Table 3 (continued) Review of canin
Page 35 and 36: Table 3 (continued) Review of canin
Page 37 and 38: Genetic analysis of primary catarac
Page 39: Genetic analysis of primary catarac
Page 63 and 64: Retrospective study on prevalence a
Page 81 and 82: CHAPTER 5 Genetic evaluation of pri
Page 83 and 84: Zusammenfassung Auf der Basis von o
Page 85 and 86: Materials and methods The results o
Page 87 and 88: Results The 615 ophthalmologically
Page 89 and 90: Discussion Phenotype based selectio
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References BARNETT, K.C. (1976): Co
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Tab. 2: Means and ranges of relativ
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Tab. 4: Prevalences of early onset
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Fig. 1: Cumulative percentages of p
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Fig. 3: Cumulative percentages of p
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Evaluation of canine HSF4 with here
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Molecular genetic analysis of prima
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Position of gene (Mb) Molecular gen
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General discussion General discussi
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General discussion (Rubin, 1989; Ge
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General discussion References Barne
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General discussion 132
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Summary Anja Engelhardt (2007) Summ
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Summary advantageous selection stra
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Erweiterte Zusammenfassung Anja Eng
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Zusammenfassung und 617 mehrfarbige
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Zusammenfassung einem einfachen rez
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Zusammenfassung Evaluierung des Hit
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Zusammenfassung Kopplungs- und Asso
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Appendix Appendix Table 1 Survey of
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Appendix Table 3 Survey of 45 micro
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Table 3 (continued) Appendix VI
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Position of gene (Mb) Table 4 (cont
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Position of gene (Mb) Appendix Tabl
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Position of gene (Mb) Table 5 (cont
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Appendix Legend for pedigrees consi
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Appendix Figure 2 Second pedigree o
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Appendix Figure 4 Pedigree of wire-
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Appendix Figure 6 Pedigree of subfa
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Laboratory paraphernalia Equipment
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dNTP solution Appendix 100 µl dATP
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Enzymes Appendix Taq-DNA-Polymerase
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Publications CHAPTER 12 List of pub
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Publications XXX
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Acknowledgements Acknowledgements M
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