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1.
Anim Genet ; 43(3): 309-14, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22486502

RESUMEN

On the basis of correlations between pairwise individual genealogical kinship coefficients and allele sharing distances computed from genotyping data, we propose an approximate Bayesian computation (ABC) approach to assess pedigree file reliability through gene-dropping simulations. We explore the features of the method using simulated data sets and show precision increases with the number of markers. An application is further made with five dog breeds, four sheep breeds and one cattle breed raised in France and displaying various characteristics and population sizes, using microsatellite or SNP markers. Depending on the breeds, pedigree error estimations range between 1% and 9% in dog breeds, 1% and 10% in sheep breeds and 4% in cattle breeds.


Asunto(s)
Bovinos/genética , Perros/genética , Linaje , Ovinos/genética , Crianza de Animales Domésticos/métodos , Animales , Teorema de Bayes , Cruzamiento/métodos , Simulación por Computador , Francia , Genotipo , Repeticiones de Microsatélite , Polimorfismo de Nucleótido Simple , Especificidad de la Especie
2.
J Anim Breed Genet ; 129(3): 206-17, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22583325

RESUMEN

A pedigree analysis was performed on eight French dairy cattle breeds to assess their change in genetic variability since a first analysis completed in 1996. The Holstein, Normande and Montbéliarde breeds are selected internationally with over hundreds of thousands cows registered in the performance recording system. Three breeds are internationally selected but with limited numbers of cows in France (Brown Swiss, French Simmental and French Red Pied). The last two remaining breeds (Abondance and Tarentaise) are raised at regional level. The effective numbers of ancestors of cows born between 2004 and 2007 varied between 15 (Abondance and Tarentaise) and 51 (French Red Pied). The effective population sizes (classical approach) varied between 53 (Abondance) and 197 (French Red Pied). This article also compares the genetic variability of the ex situ (collections of the French National Cryobank) and in situ populations. The results were commented in regard to the recent history of gene flows in the different breeds as well as the existence of more or less stringent bottlenecks. Our results showed that whatever the size of the breeds, their genetic diversity impoverished quite rapidly since 1996 and they all could be considered as quite poor from a genetic diversity point of view. It shows the need for setting up cryobanks as gene reservoirs as well as sustainable breeding programmes that include loss of genetic diversity as an integrated control parameter.


Asunto(s)
Bovinos/genética , Industria Lechera , Evolución Molecular , Variación Genética/genética , Linaje , Animales , Bovinos/anatomía & histología , Femenino , Sitios Genéticos/genética , Endogamia , Masculino , Densidad de Población , Probabilidad
3.
J Dairy Sci ; 94(8): 4100-8, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21787945

RESUMEN

Holstein-Friesian (HF) gene bank collections were established in France, the Netherlands, and the United States to conserve genetic diversity for this breed. Genetic diversity of HF collections within and between countries was assessed and compared with active male HF populations in each country by using pedigree data. Measures of genetic diversity such as probability of gene origin inbreeding and kinship were calculated. The cryobanks have captured substantial amounts of genetic diversity for the HF compared with the current populations. A substantial part of the US, French, and Dutch collections seems to be genetically similar. On the other hand, the US collection in particular represents an interesting reservoir of HF genes of the past. Gene banks can play an important role in conserving genetic diversity within livestock breeds over time, and may support industry in the future when needed.


Asunto(s)
Cruzamiento , Bovinos/genética , Bancos de Esperma , Animales , Criopreservación/veterinaria , Francia , Variación Genética/genética , Endogamia , Masculino , Países Bajos , Linaje , Estados Unidos
4.
Animal ; 14(4): 670-680, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31685075

RESUMEN

Conservation of animal genetic resources requires regular monitoring and interventions to maintain population size and manage genetic variability. This study uses genealogical information to evaluate the impact of conservation measures in Europe, using (i) data from the Domestic Animal Diversity Information System (DAD-IS) and (ii) a posteriori assessment of the impact of various conservation measures on the genetic variability of 17 at-risk breeds with a wide range of interventions. Analysis of data from DAD-IS showed that 68% of national breed populations reported to receive financial support showed increasing demographic trends, v. 51% for those that did not. The majority of the 17 at-risk breeds have increased their numbers of registered animals over the last 20 years, but the changes in genetic variability per breed have not always matched the trend in population size. These differences in trends observed in the different metrics might be explained by the tensions between interventions to maintain genetic variability, and development initiatives which lead to intensification of selection.


Asunto(s)
Bovinos/genética , Conservación de los Recursos Naturales , Equidae/genética , Variación Genética , Ganado/genética , Rumiantes/genética , Animales , Animales Domésticos , Cruzamiento , Demografía , Europa (Continente) , Femenino , Masculino , Linaje , Densidad de Población
5.
Sci Rep ; 7(1): 11466, 2017 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-28904385

RESUMEN

In humans, the clinical and molecular characterization of sporadic syndromes is often hindered by the small number of patients and the difficulty in developing animal models for severe dominant conditions. Here we show that the availability of large data sets of whole-genome sequences, high-density SNP chip genotypes and extensive recording of phenotype offers an unprecedented opportunity to quickly dissect the genetic architecture of severe dominant conditions in livestock. We report on the identification of seven dominant de novo mutations in CHD7, COL1A1, COL2A1, COPA, and MITF and exploit the structure of cattle populations to describe their clinical consequences and map modifier loci. Moreover, we demonstrate that the emergence of recessive genetic defects can be monitored by detecting de novo deleterious mutations in the genome of bulls used for artificial insemination. These results demonstrate the attractiveness of cattle as a model species in the post genomic era, particularly to confirm the genetic aetiology of isolated clinical case reports in humans.


Asunto(s)
Estudios de Asociación Genética , Ganado/genética , Mutación , Fenotipo , Animales , Bovinos , Análisis Mutacional de ADN , Modelos Animales de Enfermedad , Enfermedades Genéticas Congénitas , Predisposición Genética a la Enfermedad , Genómica/métodos , Humanos , Linaje , Secuenciación Completa del Genoma
6.
J Anim Sci ; 88(2): 505-16, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19820041

RESUMEN

Pedigree information was analyzed in 7 small populations of sheep raised in France (Bleu du Maine, Charmoise, Cotentin, on-farm Romanov, Romanov ex situ in vivo, Roussin de la Hague, Solognote) to estimate their genetic variability. The pedigree information for each breed, estimated by the number of equivalent generations traced, ranged from rather poor (4.6) to very good (10.5) when compared with other studies. On the basis of probabilities of gene origin, the effective number of ancestors ranged from 17 (on-farm Romanov breed) to 59 (Bleu du Maine). On the basis of the rate of inbreeding, the realized effective size was found to range from 65 (Romanov breed ex situ) to 231 (Bleu du Maine). The average kinship coefficients between rams from which semen doses are available in the French National Cryobank and the active ram and ewe populations were also computed. Results found in each breed were analyzed by taking into consideration the demographic evolution of the breeds, their management practices, and the use of cryopreservation as a way to preserve genetic variability. It appeared quite clear that, in populations in which AI with frozen semen is seldom used, factors that mainly affect the genetic variability are the female-to-male ratio, which should be as small as possible, and the number of reproducing female offspring by males, which should be as balanced as possible. Finally, our work showed that all populations under study have fairly good genetic variability in comparison with other species, despite their scarce numbers.


Asunto(s)
Crianza de Animales Domésticos/métodos , Cruzamiento/métodos , Linaje , Ovinos/genética , Animales , Femenino , Francia , Genes/genética , Variación Genética/genética , Endogamia , Masculino
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