RESUMEN
Transmission Ratio Distortion (TRD) is a genetic phenomenon widely demonstrated in several livestock species, but barely in equine species. The TRD occurs when certain genotypes are over- or under-represented in the offspring of a particular mating and can be caused by a variety of factors during gamete formation or during embryonic development. For this study, 126 394 trios consisting of a stallion, mare, and offspring were genotyped using a panel of 17 neutral microsatellite markers recommended by the International Society for Animal Genetics for paternity tests and individual identification. The number of alleles available for each marker ranges from 13 to 18, been 268 the total number of alleles investigated. The TRDscan v.2.0 software was used with the biallelic procedure to identify regions with distorted segregation ratios. After completing the analysis, a total of 12 alleles (out of 11 microsatellites) were identified with decisive evidence for genotypic TRD; 3 and 9 with additive and heterosis patterns, respectively. In addition, 19 alleles (out of 10 microsatellites) were identified displaying allelic TRD. Among them, 14 and 5 were parent-unspecific and stallion-mare-specific TRD. Out of the TRD regions, 24 genes were identified and annotated, predominantly associated with cholesterol metabolism and homeostasis. These genes are often linked to non-specific symptoms like impaired fertility, stunted growth, and compromised overall health. The results suggest a significant impact on the inheritance of certain genetic traits in horses. Further analysis and validation are needed to better understand the TRD impact before the potential implementation in the horse breeding programme strategies.
Asunto(s)
Patrón de Herencia , Programas Informáticos , Caballos/genética , Animales , Masculino , Femenino , Marcadores Genéticos , Genotipo , Fenotipo , AlelosRESUMEN
BACKGROUND: Vitiligo and melanoma are relatively common disorders in grey Pura Raza Español horses and other horse breeds with grey-coloured coats. OBJECTIVES: To determine the breed prevalence, environmental risks factors and estimate the genetic parameters for vitiligo and melanoma in Pura Raza Español horses. STUDY DESIGN: Retrospective cohort study. METHODS: We analysed data from a large worldwide population of Pura Raza Español horses. The database included the vitiligo and melanoma scores, on either a four- or six-point linear scale, of 11,436 horses. Genetic parameters were estimated using a Bayesian genetic animal model including the four associated environmental risk factors as systematic effects. Inbreeding was used as a covariate, and animal and residual effects were included as random effects. RESULTS: Of the horses included in the study, 2.8 and 20.5% showed some traces of vitiligo around the eyes and mouth, respectively, while 1.6% showed varying degrees of melanoma. Age, coat colour and inbreeding were significantly associated with the three outcomes studied. The estimated heritability for the whole population was 0.09 (s.d. +0.019), 0.44 (s.d. +0.031) and 0.13 (s.d. +0.037), for eye vitiligo score, nostril vitiligo score and melanoma scores respectively. The genetic correlations ranged from 0.42 (s.d. +0.084) between eye and nostril vitiligo score to 0.15 (s.d. +0.096) between nostril vitiligo and melanoma. MAIN LIMITATIONS: Vitiligo scores for the perianal regions were not collected. The veterinarian responsible for each assessment was not recorded. CONCLUSIONS: Vitiligo and melanoma are prevalent in this population and those environmental risk factors and genetics both have an effect on the clinical expression of the diseases. These findings may help to reduce prevalence through breeding programmes.
Asunto(s)
Predisposición Genética a la Enfermedad , Enfermedades de los Caballos/genética , Melanoma/veterinaria , Vitíligo/veterinaria , Envejecimiento , Animales , Femenino , Enfermedades de los Caballos/etiología , Caballos , Endogamia , Masculino , Melanoma/etiología , Melanoma/genética , Factores de Riesgo , Pigmentación de la Piel , Vitíligo/etiología , Vitíligo/genéticaRESUMEN
REASONS FOR PERFORMING STUDY: Cresty neck is a relatively common morphological defect in Pura Raza Español horses and other Baroque type horse breeds, which adversely affects the breeding industry. OBJECTIVES: To establish the within-breed prevalence, possible associated factors and heritability of cresty neck in Pura Raza Español horses. STUDY DESIGN: Cross-sectional analysis of a large worldwide database of Pura Raza Español horses. METHODS: The database included evaluations of 10,929 Pura Raza Español horses from 24 countries. Cresty neck score, on a 9 point scale, girth-to-height ratio, height at the withers, length of neck, head-neck junction and neck-body junction were recorded. A Bayesian genetic animal model included the following systematic effects: girth-to-height ratio, age, sex, coat colour and geographical area of the stud. Animal and residual effects were included as random effects. RESULTS: Within this Pura Raza Español population, 8.91% had a cresty neck score ≥5, which is the threshold for penalty or disqualification in the studbook of the breed. The age, sex, coat colour and stud geographical area were significantly associated with cresty neck score. The estimated heritability coefficient for cresty neck score was 0.37 (s.d. = 0.034) and genetic correlation between cresty neck score and other conformational traits ranged from -0.06 (height-at-withers) to -0.21 (neck-body junction). CONCLUSIONS: Cresty neck is a prevalent defect in Pura Raza Español horses, associated with age, sex, coat colour and other conformational traits, with a moderate level of heritability. Breeding to select against this condition may therefore be beneficial in this breed.
Asunto(s)
Enfermedades de los Caballos/genética , Cuello/anatomía & histología , Obesidad/veterinaria , Adiposidad/genética , Adiposidad/fisiología , Envejecimiento , Animales , Femenino , Predisposición Genética a la Enfermedad , Caballos , Masculino , Factores de RiesgoRESUMEN
Calpains play an important role in the postmortem tenderization process of meat and several SNP in the mu-calpain gene (CAPN1) have been reported to be associated with tenderness in beef cattle. Our objectives were to identify the previously reported CAPN1 331G>C SNP and to detect new polymorphisms in this gene in Spanish maternal beef breeds. A fragment (exon 8 to 10) of the bovine CAPN1 gene was sequenced and genotyped in a sample of the main Spanish maternal beef breeds including Retinta, Morucha, and Avilenã Negra-Ibérica. These breeds are characterized for their high meat quality, their adaptation to adverse environmental conditions, and their good maternal aptitude. This adaptation makes it possible to rear these breeds in the south and west of Spain, where drought and feed shortages occur frequently. Six SNP in the mu-calpain gene were found, five of which (CAPN1 80C>T, 302C>G, 310G>A, 445C>T, 524A>C) have not been reported previously. Sequences obtained for these five newly found SNP were submitted to GenBank (Accessions EU386166 to EU386183).
Asunto(s)
Calpaína/genética , Bovinos/genética , Polimorfismo de Nucleótido Simple , Alelos , Animales , Secuencia de Bases , Cartilla de ADN/genética , Femenino , Carne , Datos de Secuencia Molecular , Fenotipo , España , Especificidad de la EspecieRESUMEN
The aim of this note is to describe a reliable, fast, and cost-effective real-time PCR method for routine genotyping of mutations responsible for most coat color variation in horses. The melanocortin-1 receptor, Agouti-signaling peptide, and membrane-associated transporter protein alleles were simultaneously determined using 2 PCR protocols. The assay described here is an alternative method for routine genotyping of a defined number of polymorphisms. Allelic variants are detected in real time and no post-PCR manipulations are required, therefore limiting costs and possible carryover contamination. Data can be copied to a Microsoft Excel spreadsheet for semiautomatic determination of the genotype using a macro freely available at http://www.igijon.com/personales/fgoyache/software_i.htm (last accessed February 26, 2007). The performance of the method is demonstrated on 156 Spanish Purebred horses.
Asunto(s)
Proteína de Señalización Agouti/genética , Color del Cabello/genética , Caballos/genética , Proteínas de Transporte de Membrana/genética , Receptor de Melanocortina Tipo 1/genética , Alelos , Animales , Cartilla de ADN , Sondas de ADN , Femenino , Genotipo , Masculino , Mutación , Reacción en Cadena de la Polimerasa/métodos , Reacción en Cadena de la Polimerasa/normas , Reacción en Cadena de la Polimerasa/veterinaria , Sensibilidad y EspecificidadRESUMEN
We partially sequenced the mitochondrial hypervariable region 1 (HVR1) in 60 goats belonging to six Spanish breeds. The analysis of these and previously published sequences reveals a weak phylogeographical structure in the Iberian Peninsula breeds. Individuals from a single breed did not group into a single cluster. Furthermore, individuals from different breeds often shared single phylogenetic tree branches after UPGMA analysis. This could reflect the non-existence of breed isolation because of traditional seasonal pastoralism and annual long-distance migrations. Three goats belonging to the C maternal lineage were found, demonstrating a wider than previously thought distribution for this lineage.
