Genetic variation in genes associated with brachycephaly

Domestication followed by controlled breeding has generated many dog breeds, displaying high morphological variation. One type of dogs with a dis-tinct morphology is brachycephalic dogs, characterized by a shortened muz-zle, a wide head and widely spaced eyes. The phenotype of brachycephalic dogs ha...

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Autor principal: Johansson, Elin
Formato: Second cycle, A2E
Lenguaje:sueco
Inglés
Publicado: 2019
Materias:
Acceso en línea:https://stud.epsilon.slu.se/14846/
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author Johansson, Elin
author_browse Johansson, Elin
author_facet Johansson, Elin
author_sort Johansson, Elin
collection Epsilon Archive for Student Projects
description Domestication followed by controlled breeding has generated many dog breeds, displaying high morphological variation. One type of dogs with a dis-tinct morphology is brachycephalic dogs, characterized by a shortened muz-zle, a wide head and widely spaced eyes. The phenotype of brachycephalic dogs has been associated with several health issues, where one of the most obvious is the Brachycephalic Obstructive Airway syndrome (BOAS) which affects the breathing capacity and thermoregulation of the dog. Several stud-ies have aimed to identify the molecular background of the shorter snouts in brachycephalic dogs. So far, mutations in genes such as Bone Morphogenic Protein 3 (BMP3), Fibroblast growth factor 4 (FGF4), SPARC-related mod-ular calcium binding gene 2 (SMOC2) and DISHEVELLED 2 (DVL2) are thought to be associated with the altered skull shape causing canine brachy-cephaly. The aim of this master thesis was to investigate the genetic variation in the genes SMOC2, BMP3, and DVL2 in the Swedish population of four brachycephalic breeds; Boston Terrier, English Bulldog, French Bulldog and Pug. 102 privately owned brachycephalic dogs were genotyped for the muta-tion in the SMOC2 gene, additionally, 45 of these dogs were also genotyped for the mutations in the BMP3 and DVL2 gene. The mutant variant of the SMOC2 gene was fixated in all four breeds. The mutant variant of the BMP3 gene had high allele frequency in all breeds. In Bull type breeds (Boston Terrier, English Bulldog and French Bulldog) the mutant version of the DVL2 gene was fixated, whilst all Pugs were tested wild type for the DVL2 mutation. Low genetic variation will make it more chal-lenging to improve health through genetic selection within the breeds.
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spelling RepoSLU148462019-08-23T01:00:36Z https://stud.epsilon.slu.se/14846/ Genetic variation in genes associated with brachycephaly Johansson, Elin Animal genetics and breeding Domestication followed by controlled breeding has generated many dog breeds, displaying high morphological variation. One type of dogs with a dis-tinct morphology is brachycephalic dogs, characterized by a shortened muz-zle, a wide head and widely spaced eyes. The phenotype of brachycephalic dogs has been associated with several health issues, where one of the most obvious is the Brachycephalic Obstructive Airway syndrome (BOAS) which affects the breathing capacity and thermoregulation of the dog. Several stud-ies have aimed to identify the molecular background of the shorter snouts in brachycephalic dogs. So far, mutations in genes such as Bone Morphogenic Protein 3 (BMP3), Fibroblast growth factor 4 (FGF4), SPARC-related mod-ular calcium binding gene 2 (SMOC2) and DISHEVELLED 2 (DVL2) are thought to be associated with the altered skull shape causing canine brachy-cephaly. The aim of this master thesis was to investigate the genetic variation in the genes SMOC2, BMP3, and DVL2 in the Swedish population of four brachycephalic breeds; Boston Terrier, English Bulldog, French Bulldog and Pug. 102 privately owned brachycephalic dogs were genotyped for the muta-tion in the SMOC2 gene, additionally, 45 of these dogs were also genotyped for the mutations in the BMP3 and DVL2 gene. The mutant variant of the SMOC2 gene was fixated in all four breeds. The mutant variant of the BMP3 gene had high allele frequency in all breeds. In Bull type breeds (Boston Terrier, English Bulldog and French Bulldog) the mutant version of the DVL2 gene was fixated, whilst all Pugs were tested wild type for the DVL2 mutation. Low genetic variation will make it more chal-lenging to improve health through genetic selection within the breeds. Domesticering följt av kontrollerad avel har genererat många hundraser med stora variationer i utseende. En typ av hundar som uppvisar ett distinkt utse-ende är brakycefala (trubbnosiga) hundar, karaktäriserat av en kort nos, brett huvud och med stort avstånd mellan ögonen. Fenotypen hos brakycefala hun-dar har kopplats till hälsoproblem där ett av de mest påtagliga problemen är Brachycephalic obstructive airway syndrome (BOAS), ett syndrom som på-verkar hundens andning och förmåga att reglera sin kroppstemperatur. Fler-talet studier har utförts för att identifiera de molekylära bakomliggande orsa-kerna till den kortare nosen hos brakycefala hundar. Hittills har mutationer i gener så som Bone Morphogenic Protein 3 (BMP3), Fibroblast growth factor 4 (FGF4), SPARC-related modular calcium binding gene 2 (SMOC2) och DISHEVELLED 2 (DVL2) kunnat kopplas till den avvikande huvudformen hos brakycefala hundar. Syftet för detta examensarbete var att undersöka den genetiska variationen i generna SMOC2, BMP3 och DVL2 för den svenska populationen av bostonterrier, engelsk bulldogg, fransk bulldogg och mops. Totalt genotypades 102 privatägda brakycefala hundar för mutationen i SMOC2 genen, dessutom genotypades 45 av dessa hundar för mutationerna i BMP3 och DVL2. Denna studie pekar på att mutationen i SMOC2 var fixerad i de fyra raserna. I de fyra raserna var allelfrekvensen för den muterade BMP3 allelen hög. I de tre raserna av bull-typ (bostonterrier, engelsk bulldogg och fransk bulldogg) var mutationen i DVL2 fixerad, medan alla mopsar var ge-notypade som vildtyp. Låg genetisk variation kommer göra det mer utma-nande att förbättra hälsan genom genomisk selektion inom raserna. 2019-07-22 Second cycle, A2E NonPeerReviewed application/pdf sv https://stud.epsilon.slu.se/14846/8/johansson_e_190704.pdf Johansson, Elin, 2019. Genetic variation in genes associated with brachycephaly. Second cycle, A2E. Uppsala: (VH) > Dept. of Animal Breeding and Genetics (until 231231) <https://stud.epsilon.slu.se/view/divisions/OID-670.html> urn:nbn:se:slu:epsilon-s-10775 eng
spellingShingle Animal genetics and breeding
Johansson, Elin
Genetic variation in genes associated with brachycephaly
title Genetic variation in genes associated with brachycephaly
title_full Genetic variation in genes associated with brachycephaly
title_fullStr Genetic variation in genes associated with brachycephaly
title_full_unstemmed Genetic variation in genes associated with brachycephaly
title_short Genetic variation in genes associated with brachycephaly
title_sort genetic variation in genes associated with brachycephaly
topic Animal genetics and breeding
url https://stud.epsilon.slu.se/14846/
https://stud.epsilon.slu.se/14846/