Genetic improvement of hip-extended scores in 3 breeds of guide dogs using estimated breeding values: Notable progress but more improvement is needed.

Autor: Leighton EA; The Seeing Eye, Inc, Morristown, New Jersey, United States of America., Holle D; The Seeing Eye, Inc, Morristown, New Jersey, United States of America., Biery DN; Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, United States of America., Gregor TP; Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, United States of America., McDonald-Lynch MB; Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, United States of America., Wallace ML; Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, United States of America., Reagan JK; Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, United States of America., Smith GK; Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, United States of America.
Jazyk: angličtina
Zdroj: PloS one [PLoS One] 2019 Feb 22; Vol. 14 (2), pp. e0212544. Date of Electronic Publication: 2019 Feb 22 (Print Publication: 2019).
DOI: 10.1371/journal.pone.0212544
Abstrakt: Two hip quality phenotypes-a hip-extended score assigned by a board certified radiologist and the PennHIP distraction index-were analyzed to estimate genetic parameters and to calculate estimated breeding values used for selecting replacement breeders. Radiographs obtained at 12-18 months of age were available on 5,201 German Shepherd Dogs, 4,987 Labrador Retrievers and 2,308 Golden Retrievers. Obtained by fitting a two-trait model using Bayesian techniques, estimates of heritability for the hip-extended score were 0.76, 0.72, and 0.41 in German Shepherd Dogs, Labrador Retrievers, and Golden Retrievers, respectively, while estimated heritabilities for distraction index were 0.60, 0.66 and 0.59, respectively. Genetic correlations between the two hip quality measures were -0.28 in German Shepherd Dogs, -0.21 in Labrador Retrievers, and -0.29 in Golden Retrievers. Genetic selection for improved hip quality based upon the hip extended score phenotype began in 1980. Among first generation puppies, 34% of 273 German Shepherd Dogs, 55% of 323 Labrador Retrievers, and 43% of 51 Golden Retrievers had an Excellent hip extended score. After 8 generations of selection, mostly based on estimated breeding values derived from the hip extended score, over 93% of 695 German Shepherd Dogs, 94% of 528 Labrador Retrievers, and 87% of 116 Golden Retrievers received an Excellent hip extended score. With respect to PennHIP distraction index values among these same dogs, median values were at or above 0.30 for all 3 breeds meaning that half or more of dogs possessing the Excellent hip-extended-score phenotype remained susceptible to developing the osteoarthritis of canine hip dysplasia. Genetic improvement of the hip-extended-view phenotype to its desired biological endpoint left a surprising proportion of dogs expressing sufficient joint laxity to place them in an osteoarthritis at-risk state as they age. Only by directly applying selection pressure to reduce distraction index was marked reduction in joint laxity noted.
Competing Interests: Most of the data collection for this publication occurred while PennHIP was a not-for-profit service wholly owned and operated by the University of Pennsylvania. In December, 2013 PennHIP was acquired by Antech Imaging Services of Fountain Valley, CA, United States of America. Antech Imaging Services is a segment of VCAAntech, which was purchased in 2018 by Mars, Inc. Since 2013 PennHIP has been a for-profit diagnostic service available world-wide. Dr. Gail K. Smith is currently an employee of Antech Imaging Services, where he is the Director of AIS PennHIP. The Seeing Eye, Inc. is a not-for-profit charity with a focused mission to provide healthy, well-trained dogs to serve as guides for blind people. In pursuit of this mission, The Seeing Eye has, occasionally, funded targeted research in areas of canine health. One such project was to develop an improved, alternative method for assessing hip quality in young dogs. Funding for much of this targeted research support was channeled through Morris Animal Foundation, who provides oversight and an established peer-review process for awarding research grants. Some of the funds dispensed by Morris Animal Foundation for developing the distraction index method originated with The Seeing Eye, Inc. During some of the years when this funding support was provided by The Seeing Eye, Drs. Eldin A. Leighton and Dolores Holle were employed by The Seeing Eye and participated in the decision-making process that led to this funding support. After the PennHIP program was established as a service provided by the University of Pennsylvania and later by AIS, The Seeing Eye was a consumer of the service, obtaining PennHIP scores on thousands of dogs under contract with the University of Pennsylvania and later with AIS. The Seeing Eye holds no patents or income producing interest in PennHIP. Our disclosure of these relationships is intended to provide transparency to our readers. Furthermore, these relationships do not alter our adherence to PLOS ONE policies on sharing data and materials.
Databáze: MEDLINE
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