Programa de recuperación de la raza bovina pallaresa

Resumen de la comunicación presentada al III Congreso Ibérico sobre Recursos Genéticos Animales

Los microsatélites (STR´s), marcadores moleculares de ADN por excelencia para programas de conservación: una revisión (Microsatellites (STR’s), ADN Molecular Markers for Excellency for conservation programs: A review)

The science of genetics has been revolutionized in recent years by the techniques of molecular biology, which make it possible to elucidate complex physiological functions at the gene level: especially after discovery of the Polymerase Chain Reaction (PCR), which enabled studying and measuring genetic variability at the molecular level. The utilization of molecular markers of the microsatellite type is especially noteworthy in this regard, because of the particular intrinsic properties which make them the markers of choice for both basic genetic studies and animal improvement The most important advances achieved in genetics based on information provided by these markers have been analysis of population genetics, creation of the most sophisticated gene maps, and detection of important genes. Measurement of DNA polymorphism by means of these genetic markers in organisms with complex genomes, has made possible the mapping, manipulation and cloning of genes associated with characters of biological interest. This article reviews some of the practical uses derived from identification and analysis of DNA polymorphism, especially those related to studies based on microsatellite-type markers

Analysis of genetic diversity and conservation priorities in Iberian pigs based on microsatellite markers

The Iberian breed is the most important pig population of the Mediterranean type. The genetic structure of two strains (Torbiscal and Guadyerbas) and three varieties (Retinto, Entrepelado and Lampiño) of this breed was studied using 173 pigs genotyped for 36 microsatellites. In addition, 40 pigs of the related Duroc breed were also analysed. In the 1960s, the Iberian breed's numbers were severely reduced by disease, due to economic change and to crossbreeding. Varieties are in danger of disappearance or blending. A new conservation strategy is required. An analysis was performed that allows us to ascertain the loss or gain of genetic diversity if one or several subpopulations are removed. The results are compared with those using the Weitzman method. The two methodologies produce conservation priorities that are completely different, the reason being that the Weitzman method does not take into account the within-population genetic diversity. We apply optimal contribution theory and a new procedure for cluster analysis, and discuss their value in the general framework of the problems of setting of priorities and tactics for the conservation of genetic resources

Genetic diversity and patterns of population structure in Creole goats from the Americas

Biodiversity studies are more efficient when large numbers of breeds belonging to several countries are involved, as they allow for an in-depth analysis of the within- and between-breed components of genetic diversity. A set of 21 microsatellites was used to investigate the genetic composition of 24 Creole goat breeds (910 animals) from 10 countries to estimate levels of genetic variability, infer population structure and understand genetic relationships among populations across the American continent. Three commercial transboundary breeds were included in the analyses to investigate admixture with Creole goats. Overall, the genetic diversity of Creole populations (mean number of alleles = 5.82 ± 1.14, observed heterozygosity = 0.585 ± 0.074) was moderate and slightly lower than what was detected in other studies with breeds from other regions. The Bayesian clustering analysis without prior information on source populations identified 22 breed clusters. Three groups comprised more than one population, namely from Brazil (Azul and Graúna; Moxotó and Repartida) and Argentina (Long and shorthair Chilluda, Pampeana Colorada and Angora-type goat). Substructure was found in Criolla Paraguaya. When prior information on sample origin was considered, 92% of the individuals were assigned to the source population (threshold q ≥ 0.700). Creole breeds are well-differentiated entities (mean coefficient of genetic differentiation = 0.111 ± 0.048, with the exception of isolated island populations). Dilution from admixture with commercial transboundary breeds appears to be negligible. Significant levels of inbreeding were detected (inbreeding coefficient > 0 in most Creole goat populations, P < 0.05). Our results provide a broad perspective on the extant genetic diversity of Creole goats, however further studies are needed to understand whether the observed geographical patterns of population structure may reflect the mode of goat colonization in the Americas.This study was partially supported by Instituto Nacional de Investigaci on y Tecnolog ıa Agraria y Alimentaria (INIA), Spain (project references: RZ2004-00037-00-00, RZ2006- 00005-C02-00, RZ2007-00005-C02-01 and RZ2007-00005-C02-02)This study was partially supported by the Brazilian Government through CNPq and CAPES.Ginja C was supported by a contract grant from the Fundacao para a Ciencia e a Tecnologia (IF/ 00866/2014), Portugal.Depto. de Producción AnimalFac. de VeterinariaTRUEpu