Partition of the genetic variability, genetic structure and relationships among seven Spanish Celtic horse breeds were studied using PCR amplification of 13 microsatellites on 481 random individuals. In addition, 60 thoroughbred horses were included. The average observed heterozygosity and the mean number of alleles were higher for the Atlantic horse breeds than for the Balearic Islands breeds. Only eight percentage of the total genetic variability could be attributed to differences among breeds (mean FST approximately 0.08; P < 0.01). Atlantic breeds clearly form a separate cluster from the Balearic Islands breeds and among the former only two form a clear clustering, while the rest of Atlantic breeds (Jaca Navarra, Caballo Gallego and Pottoka) are not consistently differentiated. Multivariate analysis showed that Asturcon populations, Losina and Balearic Islands breeds are clearly separated from each other and from the rest of the breeds. In addition to this, the use of the microsatellites proved to be useful for breed assignment.

A large number of putative single nucleotide polymorphisms (SNPs) have been identified from the bovine genome-sequencing project. However, few of these have been validated and many will turn out to be sequencing artefacts or have low minor allele frequencies. In addition, there is little information available on SNPs within coding regions, which are likely to be responsible for phenotypic variation. Therefore, additional SNP discovery is necessary to identify and validate polymorphisms both in specific genes and genome-wide. Sequence-tagged sites within 286 genes were resequenced from a panel of animals representing a wide range of European cattle breeds. For 80 genes, no polymorphisms were identified, and 672 putative SNPs were identified within 206 genes. Fifteen European cattle breeds (436 individuals plus available parents) were genotyped with these putative SNPs, and 389 SNPs were confirmed to have minor allele frequencies above 10%. The genes containing SNPs were localized on chromosomes by radiation hybrid mapping and on the bovine genome sequence by Blast. Flanking microsatellite loci were identified, to facilitate the alignment of the genes containing the SNPs in relation to mapped quantitative trait loci. Of the 672 putative SNPs discovered in this work, only 11 were found among the validated SNPs and 100 were found among the approximately 2.3 million putative SNPs currently in dbSNP. The genes studied in this work could be considered as candidates for traits associated with beef production and the SNPs reported will help to assess the role of the genes in the genetic control of muscle development and meat quality. The allele frequency data presented allows the general utility of the SNPs to be assessed.

(n = 22), and the population is divided into three distinct groups (F ST = 0.078; P < 0.001). The molecular heterozygosity (H M = 71.2 %) computed in a random sample gives an accurate vision of the real inbreeding. These parameters and the application of the concept of average relatedness allow us to recommend to the breeders the choice of the best matings to control the inbreeding level while maintaining a low paternity error rate. © Inra/Elsevier, Paris

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Summary Eleven microsatellites are used as representative neutral markers to screen a small Celtic pony breed (Asturcon). Allelic frequencies are calculated from a random sample (n = 50) to estimate some population genetic parameters, allowing the description of the population. The allelic frequencies are compared with published data from other populations with the same markers, leading to genetic distances which indicate the Asturcon position respective to such divergent populations as Equus przewalski and the Australian thoroughbred. Zusammfassung Characterisierung einer kleinen keltischen Ponyrasse. Kurzmitteilung. Elf Mikrosatelliten wurden als neutrale Marker zur genetischen Charakterisierung der Asturcon, einer kleinen keltischen Ponyrasse verwendet. Allelfrequenzen wurden aus einer Stichprobe (n = 50) geschätzt und einige genetische Parameter zur Beschreibung der Population abgeleitet. Ein Vergleich der Allelfrequenzen mit publizierten anderer Rassen führte zu genetischen Distanzen, die die Stellung der Asturcon in bezug auf solch unterschiedliche Populationen wie E. przewalski oder autralischer Vollblüter deutlich macht.