Differentiation of four Indian aboriginal cattle populations revealed by STR markers

Cattle are the most important livestock in India and play a pivotal role in agrarian economy. There are 34 recognized breeds of cattle and number of unexplored lesser known populations. The present study is a contribution towards determining genetic variation and understanding the relationship among four lesser known populations. A total of 194 unrelated DNA samples from three cattle populations of Orissa (Binjharpuri, Ghumsuri, Motu) and Hill cattle of Kumaun (Kumauni) were collected from respective breeding tracts. Genotyping was done with 23 bovine microsatellite markers as suggested by International Society for Animal Genetics (ISAG) and FAO (DAD-IS) on automated sequencer. The average observed heterozygosity in the four populations lie within the narrow range of 0.623 +/- 0.04 in Binjharpuri to 0.664 +/- 0.03 in Kumauni. Mean estimates of observed and expected heterozygosity over all loci and breeds were 0.651 +/- 0.02 and 0.720 +/- 0.01, respectively. In the overall population, the homozygote excess (F(IT)) of 0.132 +/- 0.03, was partly due to the genetic differentiation among breeds (F(ST) = 0.044 +/- 0.01) and, to a larger extent, to a significant homozygote excess within breeds (F(IS) = 0.094 +/- 0.03). The phylogenetic reconstruction from a UPGMA clustering based on Nei's Standard genetic distance yielded a tree with Binjharpuri and Ghumsuri on a single node and Motu and Kumauni on separate nodes. The most probable clustering detected by STRUCTURE in population was three. Binjharpuri and Ghumsuri animals were assigned to one cluster with high proportion of membership.     

Analysis of Geographic and Pairwise Genetic Distances Among Sheep Populations

This study assessed the usefulness of geographic and pairwise genetic distances in the characterization of five sheep populations using 15 microsatellite markers. The average F statistics across loci were F _IT = 0.523 ± 0.140, F _ST = 0.363 ± 0.131, and F _IS = 0.263 ± 0.092. The average heterozygosity was 0.716 ± 0.069, polymorphism information content was 0.691 ± 0.070, and effective number of alleles was 3.736 ± 0.998. Sheep populations clustered into group 1 (Hu and Tong breeds) and group 2 (small-tailed Han, Wadi, and Tan breeds). Reynolds’ distance varied from 0.0062 to 0.0499, and the range of gene flow (N _m) was 4.8834–40.0726 among the sheep populations. The results showed that the genetic structure of the five populations was not consistent with their genetic distances, and the population genetic divergence was not linearly related to geographic distance as indicated by a Mantel test (P = 0.7936).     

Microsatellite Analysis of Genetic Population Structure of Zebu Cattle (Bos indicus) Breeds from North-Western Region of India

The present study aims to understand the existing genetic diversity and structure of six native cattle breeds (Rathi, Tharparkar, Nagori, Mewati, Gir, and Kankrej) adapted to the north-western arid and semi-arid region of India based on microsatellite loci. Various diversity estimates, mean number of alleles (12.84); effective number of alleles (5.02); gene diversity (0.769), and observed heterozygosity (0.667) reflected the existence of substantial within-breed diversity in all the investigated cattle breeds. Mean estimates of F-statistics: F_IT = 0.144 ± 0.023, F_IS = 0.071 ± 0.021, and F_ST = 0.078 ± 0.014 were significantly different from zero (P < 0.05). The interbreed relationships indicated moderate level of breed differentiation between the six cattle breeds with least differentiation between Kankrej-Mewati pair. The phylogeny structuring further supported close grouping of Kankrej and Mewati breeds. Correspondence analysis plotted Rathi, Tharparkar, and Gir individuals into three separate areas of multivariate space; whereas, Kankrej, Mewati, and Nagori cattle showed low breed specific clustering. This reflected the existence of discrete genetic structure for Tharparkar, Rathi, and Gir, the prominent dairy breeds of the region; whereas, admixture was observed for Kankrej, Mewati, and Nagori individuals.     

Inference of population structure of purebred dairy and beef cattle using high-density genotype data

Information on the genetic diversity and population structure of cattle breeds is useful when deciding the most optimal, for example, crossbreeding strategies to improve phenotypic performance by exploiting heterosis. The present study investigated the genetic diversity and population structure of the most prominent dairy and beef breeds used in Ireland. Illumina high-density genotypes (777 962 single nucleotide polymorphisms; SNPs) were available on 4623 purebred bulls from nine breeds; Angus (n=430), Belgian Blue (n=298), Charolais (n=893), Hereford (n=327), Holstein-Friesian (n=1261), Jersey (n=75), Limousin (n=943), Montbéliarde (n=33) and Simmental (n=363). Principal component analysis revealed that Angus, Hereford, and Jersey formed non-overlapping clusters, representing distinct populations. In contrast, overlapping clusters suggested geographical proximity of origin and genetic similarity between Limousin, Simmental and Montbéliarde and to a lesser extent between Holstein, Friesian and Belgian Blue. The observed SNP heterozygosity averaged across all loci was 0.379. The Belgian Blue had the greatest mean observed heterozygosity (H_O=0.389) among individuals within breed while the Holstein-Friesian and Jersey populations had the lowest mean heterozygosity (H_O=0.370 and 0.376, respectively). The correlation between the genomic-based and pedigree-based inbreeding coefficients was weak (r=0.171; P<0.001). Mean genomic inbreeding estimates were greatest for Jersey (0.173) and least for Hereford (0.051). The pair-wise breed fixation index (F_st) ranged from 0.049 (Limousin and Charolais) to 0.165 (Hereford and Jersey). In conclusion, substantial genetic variation exists among breeds commercially used in Ireland. Thus custom-mating strategies would be successful in maximising the exploitation of heterosis in crossbreeding strategies.     

Genetic variability of dromedary camel populations based on microsatellite markers

Understanding existing levels of genetic variability of camel populations is capital for conservation activities. This study aims to provide information on the genetic diversity of four dromedary populations, including Guerzni, Harcha, Khouari and Marmouri. Blood samples from 227 individuals belonging to the aforementioned populations were obtained and genotyped by 16 microsatellite markers. A total of 215 alleles were observed, with the mean number of alleles per locus being 13.4 ± 6.26. All loci were polymorphic in the studied populations. The average expected heterozygosity varied from a maximum of 0.748 ± 0.122 in Guerzni population to a minimum of 0.702 ± 0.128 in Harcha population; Guerzni population showed the highest value of observed heterozygosity (0.699 ± 0.088), whereas Harcha population the lowest (0.646 ± 0.130). Mean estimates of F-statistics obtained over loci were F_IS = 0.0726, F_IT = 0.0876 and F_ST = 0.0162. The lowest genetic distance was obtained between Guerzni and Khouari (0.023), and the highest genetic distance between Harcha and Marmouri (0.251). The neighbour-joining phylogenetic tree showed two groups of populations indicating a cluster of Guerzni, Khouari and Marmouri, and a clear isolation of Harcha. The genetic distances, the factorial correspondence analysis, the analysis of genetic structure and the phylogenetic tree between populations revealed significant differences between Harcha and other populations, and a high similarity between Guerzni, Khouari and Marmouri. It is concluded from this study that the camel genetic resources studied are well diversified. However, the herd management, especially the random selection of breeding animals, can increase the level of genetic mixing between different populations, mainly among Guerzni, Khouari and Marmouri, that live in the same habitat and grazing area.     

Genetic variation and relationships of eighteen Chinese indigenous pig breeds

Chinese indigenous pig breeds are recognized as an invaluable component of the world''s pig genetic resources and are divided traditionally into six types. Twenty-six microsatellite markers recommended by the FAO (Food and Agriculture Organization) and ISAG (International Society of Animal Genetics) were employed to analyze the genetic diversity of 18 Chinese indigenous pig breeds with 1001 individuals representing five types, and three commercial breeds with 184 individuals. The observed heterozygosity, unbiased expected heterozygosity and the observed and effective number of alleles were used to estimate the genetic variation of each indigenous breed. The unbiased expected heterozygosity ranged between 0.700 (Mashen) and 0.876 (Guanling), which implies that there is an abundant genetic variation stored in Chinese indigenous pig breeds. Breed differentiation was shown by fixation indices (F_IT, F_IS, and F_ST). The F_ST per locus varied from 0.019 (S0090) to 0.170 (SW951), and the average F_ST of all loci was 0.077, which means that most of the genetic variation was kept within breeds and only a little of the genetic variation exists between populations. The Neighbor-Joining tree was constructed based on the Nei D_A (1978) distances and one large cluster with all local breeds but the Mashen breed, was obtained. Four smaller sub-clusters were also found, which included two to four breeds each. These results, however, did not completely agree with the traditional type of classification. A Neighbor-Joining dendrogram of individuals was established from the distance of – ln(proportions of shared alleles); 92.14% of the individuals were clustered with their own breeds, which implies that this method is useful for breed demarcation. This extensive research on pig genetic diversity in China indicates that these 18 Chinese indigenous breeds may have one common ancestor, helps us to better understand the relative distinctiveness of pig genetic resources, and will assist in developing a national plan for the conservation and utilization of Chinese indigenous pig breeds.     

Genetic diversity and population structure of 10 Chinese indigenous egg-type duck breeds assessed by microsatellite polymorphism

The genetic structure and diversity of 10 Chinese indigenous egg-type duck breeds were investigated using 29 microsatellite markers. The total number of animals examined were 569, on average 57 animals per breed were selected. The microsatellite marker set analysed provided 177 alleles (mean 6.1 alleles per locus, ranging from 3 to 10). All populations showed high levels of heterozygosity with the lowest estimate of 0.539 for the Jinding ducks, and the highest 0.609 observed for Jingjiang partridge ducks. The global heterozygote deficit across all populations (F _IT) amounted to −0.363. About 10% of the total genetic variability originated from differences among breeds, with all loci contributing significantly. An unrooted consensus tree was constructed using the NeighborNet tree based on the Reynold’s genetic distance. The structure software was used to assess genetic clustering of these egg-type duck breeds. Clustering analysis provided an accurate representation of the current genetic relations among the breeds. An integrated analysis was undertaken to obtain information on the population dynamics in Chinese indigenous egg-type duck breeds, and to better determine the conservation priorities.     

Genetic diversity in the Churra tensina and Churra lebrijana endangered Spanish sheep breeds and relationship with other Churra group breeds and Spanish mouflon

The aim of the present study was to estimate the genetic intra-breed variability of Churra tensina and Churra lebrijana endangered breeds and to establish genetic relationships with Churra, Latxa and Merino breeds, as well as Spanish mouflon, by using 28 microsatellite markers, to provide useful information for their conservation. Allele frequencies and heterozygosity revealed high genetic variation in the two endangered breeds despite their small population size. Estimates of inbreeding coefficient (F_IS) were significant for all breeds studied, except for Churra lebrijana breed. The highest inbreeding coefficient (F_IS = 0.143) was found in the Spanish mouflon. Genetic differentiation tests (F_ST = 0.121) and assignment of individuals to populations indicated the existence of defined breed populations, and low genetic flow between these breeds. The highest pairwise Reynolds distance (D_R) values were observed between Mouflon and the domestic sheep breeds. Considering only domestic sheep breeds, the Churra lebrijana breed showed the highest pairwise D_R values_. The lowest values were found between Latxa and the other domestic sheep, except for Churra lebrijana. Results of pairwise D_R values, as well as phylogenetic tree and bottleneck analysis showed an important genetic isolation of the Churra lebrijana breed from the other Churra types, and genetic signatures of a demographic bottleneck. Finally, structure analysis of populations detected a population subdivision in the Latxa sheep breed. In conclusion, this study presents valuable insight into the existing genetic variability of two Spanish endangered breeds, as well as the first study in Spanish mouflon based on microsatellite analysis. The high degree of variability demonstrated in Churra tensina and Churra lebrijana implies that these populations are rich reservoirs of genetic diversity.     

Evaluation of genetic diversity and population structure of west‐central Indian cattle breeds

Evaluations of genetic diversity in domestic livestock populations are necessary to implement region‐specific conservation measures. We determined the genetic diversity and evolutionary relationships among eight geographically and phenotypically diverse cattle breeds indigenous to west‐central India by genotyping these animals for 22 microsatellite loci. A total of 326 alleles were detected, and the expected heterozygosity ranged from 0.614 (Kenkatha) to 0.701 (Dangi). The mean number of alleles among the cattle breeds ranged from 7.182 (Khillar) to 9.409 (Gaolao). There were abundant genetic variations displayed within breeds, and the genetic differentiation was also high between the Indian cattle breeds, which displayed 15.9% of the total genetic differentiation among the different breeds. The genetic differentiation (pairwise F_ST) among the eight Indian breeds varied from 0.0126 for the Kankrej–Malvi pair to 0.2667 for Khillar–Kenkatha pair. The phylogeny, principal components analysis, and structure analysis further supported close grouping of Kankrej, Malvi, Nimari and Gir; Gaolao and Kenkatha, whereas Dangi and Khillar remained at distance from other breeds.     

Microsatellite and Mitochondrial Diversity Analysis of Native Pigs of Indo-Burma Biodiversity Hotspot

Assessment of genetic diversity in indigenous animals is an important and essential task for animal genetic improvement studies as well as conservation decision-making. The genetic diversity and evolutionary relationships among geographically and phenotypically distinct three pig breeds/types native to Indo-Burma and Eastern Himalayan global biodiversity hotspots were determined by genotyping with a panel of 22 ISAG recommended microsatellite loci as well as sequencing partial MTRNR1gene. The mean number of alleles per locus, effective number of alleles and observed heterozygosity were found to be 11.27 ± 0.85, 5.29 ± 0.34, and 0.795 ± 0.01, respectively. The moderate F_ST value (0.115 ± 0.01) indicated a fair degree of genetic differentiation among the native breeds. The Nei’s unbiased genetic identity estimates indicated less genetic distance (0.2909) between Niang Megha and Tenyi Vo pigs than the both individually with Ghoongroo breed. The divergence time was also estimated from the microsatellite analysis. Analysis of MTRNR1gene revealed distinct clustering of native Indian pigs with Chinese pigs over European pigs. The study revealed the abundance of genetic variation within native Indian pigs and their relationships as well as genetic distances.     

Genetic Diversity and Structure of Two Prominent Zebu Cattle Breeds Adapted to the Arid Region of India Inferred from Microsatellite Polymorphism

This study aims to assess the genetic diversity and population structure of two major zebu dairy breeds (Tharparkar and Rathi) adapted to the arid region of Rajasthan state of India. Various variability estimates indicate the existence of sufficient within-breed genetic diversity. Mean estimates of F-statistics are significantly different from zero: F _IS = 0.112 ± 0.029, F _IT = 0.169 ± 0.033, F _ST = 0.065 ± 0.017. The overall positive value of F _IS (0.112) and an F _IT value (0.169) that is more than the F _ST (0.065) indicate departure from random mating. The drift-based estimates reflect a moderate yet significant level of breed differentiation between the Tharparkar and Rathi breeds. The evaluation of an exact test, showing that allele frequencies across all the loci differed significantly, supports the population differentiation. This is paralleled by the outcome of neighbor-joining clustering based on allele-sharing distance measures. The allocation of a high percentage of individuals (95.7%) to their population of origin and correspondence analysis further substantiates the existence of a cohesive genetic structure in both the breeds.     

Genetic divergence between Melipona quadrifasciata Lepeletier (Hymenoptera,Apidae) populations

Melipona quadrifasciata is a stingless bee widely found throughout the Brazilian territory, with two recognized subspecies, M. quadrifasciata anthidioides, that exhibits interrupted metasomal stripes, and M. quadrifasciata quadrifasciata, with continuous metasomal stripes. This study aimed to estimate the genetic variability of these subspecies. For this purpose, 127 colonies from 15 Brazilian localities were analyzed, using nine species-specific microsatellite primers. At these loci, the number of alleles ranged from three to 15 (mean: 7.2), and the observed heterozygosity (H_o) ranged from 0.03–0.21, while the expected heterozygosity (H_e) ranged from 0.23–0.47. The genetic distances among populations ranged from 0.03–0.45. The F_ST multilocus value (0.23) indicated that the populations sampled were structured, and the clustering analysis showed the formation of two subgroups and two more distant populations. The first group contained the subspecies M. quadrifasciata quadrifasciata, and the other, the subspecies M. quadrifasciata anthidioides and the two M. quadrifasciata populations with continuous metasomal stripes from northern Minas Gerais. These results confirmed that the yellow metasomal stripes alone are not a good means for correctly identifying the different subspecies of M. quadrifasciata.     

Relationship of serum guanase levels with economic characters in zebu purebred and temperate × zebu crossbred dairy cattle

Serum guanase levels of Indian Zebu (Hariana) cattle and its crosses with different exotic levels of temperate breeds of dairy cattle were estimated in 527 animals, and their associations with economic characters were determined. The overall mean value of serum guanase level was 13.46±0.45 IU/ml of serum. An inverse relationship between the concentration of the enzyme and the frequency of cattle falling within a definite range was observed, as over 75% of the animals possessed 1 to 20 IU/ml of serum guanase. An analysis of variance revealed significant differences (P<0.01) in enzyme levels among different genetic groups under study. Hariana (Zebu) purebreds had significantly higher enzyme levels (19.60±1.85) than any of the crossbred groups, whose enzyme levels ranged from 8.99±1.41 in Red Dane F₁ half-breds to 14.30±1.11 in Brown Swiss F₁ half-breds. The correlation and regression coefficients were significantly positive for reproductive traits such as age at first service and age at first calving, and significantly negative for production traits such as lactation yield and lactation length. These results suggest that selection of dairy cattle based on low serum guanase levels might result in correlated improvements in dairy cattle productivity.     

Genome-wide analysis of Hanwoo and Chikso populations using the BovineSNP50 genotyping array

Hanwoo and Chikso are classified as Korean native cattle breeds that are currently registered with the Food and Agriculture Organization. However, there is still a lack of genomic studies to compare Hanwoo to Chikso populations. The objective of this study was to perform genome-wide analysis of Hanwoo and Chikso populations, investigating the genetic relationships between these two populations. We genotyped a total of 319 cattle including 214 Hanwoo and 105 Chikso sampled from Gangwon Province Livestock Technology Research Institute, using the Illumina Bovine SNP50K Beadchip. After performing quality control on the initially generated datasets, we assessed linkage disequilibrium patterns for all the possible SNP pairs within 1 Mb apart. Overall, average r² values in Hanwoo (0.048) were lower than Chikso (0.074) population. The genetic relationship between the populations was further assured by the principal component analysis, exhibiting clear clusters in each of the Hanwoo and Chikso populations, respectively. Overall heterozygosity for Hanwoo (0.359) was slightly higher than Chikso (0.345) and inbreeding coefficient was also a bit higher in Hanwoo (??0.015) than Chikso (??0.035). The average F_ST value was 0.036 between Hanwoo and Chikso, indicating little genetic differentiation between those two breeds. Furthermore, we found potential selection signatures including LRP1B and NTRK2 genes that might be implicated with meat and reproductive traits in cattle. In this study, the results showed that both Hanwoo and Chikso populations were not under severe level of inbreeding. Although the principal component analysis exhibited clear clusters in each of the populations, we did not see any clear evidence that those two populations are highly differentiated each other.     

Analysis of STAT5A/AvaI Gene Polymorphism in Four Italian Cattle Breeds

The STAT5A/AvaI polymorphism was investigated with PCR-RFLP in a sample of 339 cattle belonging to four breeds: Italian Friesian, Jersey, Italian Brown, and Podolica reared in south Italy. All three possible genotypes for the C/T polymorphism were identified. In these breeds, PCR-RFLP showed the predominance of the TT genotype in Italian Brown and Jersey cows; in Podolica and Italian Friesian CT is the most frequent genotype. The frequency of the T allele ranged from 0.55 to 0.81 in the analyzed populations. The distribution of genotypic and allelic frequencies at this locus was significantly different among the four populations based on a χ² test (P < 0.001), suggesting that the molecular characteristics of the STAT5A gene could be significantly affected by the breed selection. Gene heterozygosity, gene homozygosity, effective allele number, fixation index, and polymorphism information content (PIC) were calculated. The observed heterozygosity, as well as the N _e and PIC values, indicates high genetic variability in the Podolica breed. Podolica could be considered an interesting reservoir of genetic diversity for a species under high selective pressure elsewhere.     

Evaluation of Genetic Diversity,Population Structure,and Relationship Between Legendary Vechur Cattle and Crossbred Cattle of Kerala State,India

The legendary Vechur cattle of Kerala, described as a very short breed, and the crossbred (CB) Sunandini cattle population exhibited great phenotypic variation; hence, the present study attempted to analyze the genetic diversity existing between them. A set of 14 polymorphic microsatellites were chosen from FAO-ISAG panel and amplified from genomic DNA isolated from blood samples of 30 Vechur and 64 unrelated crossbred cattle, using fluorescent labeled primers. Both populations revealed high genetic diversity as evidenced from high observed number of alleles, Polymorphic Information Content and expected heterozygosity. Observed heterozygosity was lesser (0.699) than expected (0.752) in Vechur population which was further supported by positive F_IS value of 0.1149, indicating slight level of inbreeding in Vechur population. Overall, F_ST value was 0.065, which means genetic differentiation between crossbred and Vechur population was 6.5%, indicating that the crossbred cattle must have differentiated into a definite population that is different from the indigenous Vechur cows. Structure analysis indicated that the two populations showed distinct differences, with two underlying clusters. The present study supports the separation between Taurine and Zebu cattle and throws light onto the genetic diversity and relationship between native Vechur and crossbred cattle populations in Kerala state.     

Genetic differentiation between clone collections and natural populations of European black poplar (<Emphasis Type="Italic">Populus nigra</Emphasis> L.) in turkey

The European black poplar (Populus nigra L.) is an ecologically and economically important tree species for Turkey. The important and major genetic resources of species for future breeding and ex situ conservation purposes have been archived in a clone bank in Ankara by selecting clones from natural populations and old plantations throughout Turkey. There is no study to date assessing genetic composition these materials. Two-hundred-thirty-three P. nigra clones from six geographic region of Turkey (clone collection populations), and 32 trees from two natural populations (Tunceli and Melet) were genotyped by using 12 nuclear microsatellite DNA markers. There were nine clones which duplicated in various frequencies. The analysis carried out with removal of the duplicated clones revealed a moderately high genetic diversity in studied populations. The observed heterozygosities ranged from 0.59 in Tunceli natural to 0.69 in Central Anatolia clone collection populations. In general, there was excess of heterozygosity in the studied populations. Populations composed of clone collections were significantly differentiated from natural populations (F _ST = 0.17), while there was little differentiation among those populations in the clone collection (F _ST = 0.03). Two distantly located natural populations with small sizes also differed from each other (F _ST = 0.17). Genetic structure analysis revealed two distinct groups (clone collection vs natural populations) with very high membership values (>92%). Clone collection populations had high level of admixture while natural populations had homogenous genetic structure. The presence of large number of clonal duplication, reduced genetic differentiation, and high level of admixture in clone collection populations indicate that genetic resources of European black poplar were highly degraded through genetic erosion and pollution caused by intensive cultural practices and extensive dispersal of clonal materials. To understand genetic diversity and its structural pattern thoroughly in the six clone collection populations, a further study with extensive and systematic sampling of European black poplar populations in major river ecosystems in Turkey will be useful.     

Phylogenetic relationships among the European and American bison and seven cattle breeds reconstructed using the BovineSNP50 Illumina Genotyping BeadChip

Here we present the first attempt to use the BovineSNP50 Illumina Genotyping BeadChip for genome-wide screening of European bison Bison bonasus bonasus (EB), two subspecies of American bison: the plains bison Bison bison bison (PB), the wood bison Bison bison athabascae (WB) and seven cattle Bos taurus breeds. Our aims were to (1) reconstruct their evolutionary relationships, (2) detect any genetic signature of past bottlenecks and to quantify the consequences of bottlenecks on the genetic distances amongst bison subspecies and cattle, and (3) detect loci under positive or stabilizing selection. A Bayesian clustering procedure (STRUCTURE) detected ten genetically distinct clusters, with separation among all seven cattle breeds and European and American bison, but no separation between plain and wood bison. A linkage disequilibrium based program (LDNE) was used to estimate the effective population size (N _e) for the cattle breeds; N _e was generally low, relative to the census size of the breeds (cattle breeds: mean N _e = 299.5, min N _e = 18.1, max N _e = 755.0). BOTTLENECK 1.2 detected signs of population bottlenecks in EB, PB and WB populations (sign test and standardized sign test: p = 0.0001). Evidence for loci under selection was found in cattle but not in bison. All extant wild populations of bison have shown to have survived severe bottlenecks, which has likely had large effects on genetic diversity within and differentiation among groups.     

Genetic diversity of eleven European pig breeds

A set of eleven pig breeds originating from six European countries, and including a small sample of wild pigs, was chosen for this study of genetic diversity. Diversity was evaluated on the basis of 18 microsatellite markers typed over a total of 483 DNA samples collected. Average breed heterozygosity varied from 0.35 to 0.60. Genotypic frequencies generally agreed with Hardy-Weinberg expectations, apart from the German Landrace and Schwäbisch-Hällisches breeds, which showed significantly reduced heterozygosity. Breed differentiation was significant as shown by the high among-breed fixation index (overall F_ST = 0.27), and confirmed by the clustering based on the genetic distances between individuals, which grouped essentially all individuals in 11 clusters corresponding to the 11 breeds. The genetic distances between breeds were first used to construct phylogenetic trees. The trees indicated that a genetic drift model might explain the divergence of the two German breeds, but no reliable phylogeny could be inferred among the remaining breeds. The same distances were also used to measure the global diversity of the set of breeds considered, and to evaluate the marginal loss of diversity attached to each breed. In that respect, the French Basque breed appeared to be the most "unique" in the set considered. This study, which remains to be extended to a larger set of European breeds, indicates that using genetic distances between breeds of farm animals in a classical taxonomic approach may not give clear resolution, but points to their usefulness in a prospective evaluation of diversity.