Genomic Tools for the Conservation and Genetic Improvement of a Highly Fragmented Breed—The Ramo Grande Cattle from the Azores
1
CIISA—Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
2
Direção Regional da Agricultura, Secretaria Regional da Agricultura e Florestas da Região Autónoma dos Açores, Vinha Brava, 9701-861 Angra do Heroísmo, Portugal
*
Author to whom correspondence should be addressed.
Animals 2020, 10(6), 1089; https://doi.org/10.3390/ani10061089
Received: 2 June 2020
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Revised: 17 June 2020
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Accepted: 19 June 2020
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Published: 24 June 2020
(This article belongs to the Special Issue Inside the Genetics and Genomics of Variability and Functionality in Vertebrates: Current Applications and Perspectives)
Simple Summary
Inbreeding control is a key concern in managing local endangered breeds, which often have developed unique adaptation features. Ramo Grande is a local cattle breed raised in the Azores archipelago under very harsh conditions, with a census of about 1300 cows dispersed by various islands. This fragmentation is a challenge when the goal is to keep inbreeding under control. Currently, panels of genetic markers are available which enable the assessment of inbreeding and the occurrence of previous bottlenecks in a population. These panels also allow the identification of genes associated with specific production traits, if reliable phenotypic information is available. We used a panel of genetic markers and estimated that the degree of inbreeding was approaching a level of concern, while some exotic gene inflow may have occurred in the past. We were able to identify genetic markers significantly associated with longevity, which reflects the ability of these cattle to remain productive under severe environmental conditions. Genetic markers were also identified as significantly associated with age at first calving and calf growth rate. The results indicate that genomic information can be used to control inbreeding and to implement genomic selection in Ramo Grande cattle to enhance adaptation and production traits.
Ramo Grande is a local cattle breed raised in the archipelago of Azores, with a small and dispersed census, where inbreeding control is of utmost importance. A single nucleotide polymorphism (SNP) Beadchip array was used to assess inbreeding, by analysis of genomic regions harboring contiguous homozygous genotypes named runs of homozygosity (ROH), and to estimate past effective population size by analysis of linkage disequilibrium (LD). Genetic markers associated with production traits were also investigated, exploiting the unique genetic and adaptation features of this breed. A total of 639 ROH with length >4 Mb were identified, with mean length of 14.96 Mb. The mean genomic inbreeding was 0.09, and long segments of ROH were common, indicating recent inbred matings. The LD pattern indicates a large effective population size, suggesting the inflow of exotic germplasm in the past. The genome-wide association study identified novel markers significantly affecting longevity, age at first calving and direct genetic effects on calf weight. These results provide the first evidence of the association of longevity with genes related with DNA recognition and repair, and the association of age at first calving with aquaporin proteins, which are known to have a crucial role in reproduction.
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Keywords:
functional genomics; GWAS; inbreeding; local breeds; ROH; single nucleotide polymorphisms (SNPs)
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MDPI and ACS Style
Amaral, A.J.; Pavão, A.L.; Gama, L.T. Genomic Tools for the Conservation and Genetic Improvement of a Highly Fragmented Breed—The Ramo Grande Cattle from the Azores. Animals 2020, 10, 1089. https://doi.org/10.3390/ani10061089
AMA Style
Amaral AJ, Pavão AL, Gama LT. Genomic Tools for the Conservation and Genetic Improvement of a Highly Fragmented Breed—The Ramo Grande Cattle from the Azores. Animals. 2020; 10(6):1089. https://doi.org/10.3390/ani10061089
Chicago/Turabian StyleAmaral, Andreia J., Ana L. Pavão, and Luis T. Gama. 2020. "Genomic Tools for the Conservation and Genetic Improvement of a Highly Fragmented Breed—The Ramo Grande Cattle from the Azores" Animals 10, no. 6: 1089. https://doi.org/10.3390/ani10061089
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