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1.
Criollo horse populations descend from horses brought from the Iberian Peninsula over the period of colonization (15th to 17th century). They are spread throughout the Americas and have potentially undergone genetic hybridization with other breeds in the recent past. In this study, 25 autosomal microsatellites were genotyped in 50 horse breeds representing Criollo populations from 12 American countries (27 breeds), breeds from the Iberian Peninsula (19), one breed each from France and Morocco and two cosmopolitan horse breeds (Thoroughbred and Arabian). The genetic relationships among breeds identified five clusters: Celtic; Iberian; North American with Thoroughbred influence; most Colombian breeds; and nearly all other Criollo breeds. The group of “all other Criollo breeds” had the closest genetic relationship with breeds originating from the Iberian Peninsula, specifically with the Celtic group. For the whole set of Criollo breeds analysed, the estimated genetic contribution from other breeds was approximately 50%, 30% and 20% for the Celtic, Iberian and Arab-Thoroughbred groups, respectively. The spatial distribution of genetic diversity indicates that hotspots of genetic diversity are observed in populations from Colombia, Ecuador, Brazil, Paraguay and western United States, possibly indicating points of arrival and dispersion of Criollo horses in the American continent. These results indicate that Criollo breeds share a common ancestry, but that each breed has its own identity.  相似文献   

2.
The genetic variability within the Uruguayan Creole horse and its relationship to a group of geographically or historically related breeds (Spanish Pure-bred, Barb, Quarter horse, Paso Fino, Peruvian Paso, Arabian and Thoroughbred horse), was evaluated using 25 loci (seven of blood groups, nine of protein polymorphisms and nine microsatellites) analyzed on a total of 145 Uruguayan Creole horses. In this study, blood group and protein polymorphism variants that are considered to be breed markers of Spanish Pure-bred and Barb horses were detected in the Creole breed. Conversely, some microsatellites and protein polymorphisms alleles were found uniquely in the Creole horse. American horse breeds together with Barb and Arabian horses clearly formed a separate cluster from the Spanish pure-bred and Thoroughbred breeds, as shown by an UPGMA dendrogram based on Nei's standard genetic distance. Data in this study provided evidence for considerable genetic variation within Uruguayan Creole horses and of a distinctive breed profile. Both traits were most likely inherited from the XVIth century Spanish horses, more closely related to Barb than to Spanish Pure-bred.  相似文献   

3.
It is well known that horse breeding in Bulgaria is a cultural heritage in Bulgaria, dating from prehistoric and historic times. Until now, molecular data on Bulgarian horses from the plain regions of the country were not available. Therefore, for the first time, we have collected genetic information about some modern horse breeds from the plain regions in Bulgaria. A total of 50 horses originating from different families from two different breeds were investigated: the first one was the Pleven horse (n = 11, breeding in the Danubian Plain), and the second one was the East Bulgarian horse breed (n = 39, Shumen district). These breeds were genotyped according to the mitochondrial D-loop region. The results showed that the Pleven horse particularly carries the European haplogroup L (45.45%), followed by the Middle East haplogroup C (27.27%). In contrast to the Pleven horse, the East Bulgarian horse breed revealed almost equal frequencies of the European specific haplogroup L (33.33%) and the Central Asiatic haplogroup Q (35.90%). Analyses of these two horse breeds revealed a specific genetic profile, but it is obvious that the East Bulgarian horse showed an unusual, mixed profile—a massive admixture with the Asiatic-type haplogroup Q and a high haplogroup diversity. In conclusion, the differences in genetic structure of the two plain horse breeds may be explained with the various horse breeds involved in their formation.  相似文献   

4.
The Mangalarga Marchador (MM) horse breed has expressive importance in the Brazilian economy. Thus, the aim of this study was to investigate diversity in the MM breed. A database with a total of 3,193 genotyped horses was used (MM, n = 2,829; Andalusian – AND, n = 67; Pure Blood Lusitano – LUS, n = 43; English Thoroughbred – THO, n = 54; Arabian – ARA, n = 99; Campolina – CAM, n = 61; and Mangalarga – MAN, n = 40) for 13 microsatellite. Diversity parameters were estimates, such as mean number of alleles (Nma) and the number of rare alleles (AR), expected heterozygosity (He), F statistics, genetic distances, Hardy-Weinberg equilibrium test (HWE), population structure, and others. The Nma was 10.85, the AR was prevalent in the MM, and the He was 0.7402. In MM, the values of Fis (−0.0195), Fit (0.0566), Fst (0.0748), and deviations of HWE were observed. The genetic distances of the ARA and THO breeds with the other breeds were greater than the distances between the Brazilian breeds and between these and the breeds in the Iberian Peninsula. The population structure indicated that MM was substructured, yet there were some more genetically defined breeding farms. The genetic diversity is satisfactory for MM conservation, but the population is substructure, and parameters indicate moderate gene flow and the existence, though few, of crosses with other horse breeds. Immediate implementation of a genetic breeding program is required, especially seeking to conserve the structure of the MM breed as a well-defined genetic entity.  相似文献   

5.
This study was the first to analyze the polymorphic characteristics of a wide range of genetic markers in three Lithuanian horse breeds. Genetic variation at seven red blood cell alloantigen (blood group) loci, 10 biochemical genetic loci and 16 microsatellites was examinated in 31 Zemaitukai, 30 large-type Zemaitukai and 24 Lithuanian Heavy Draught horse and compared to that of other domestic horse breeds. Genetic variability of the Zemaitukai breeds based upon blood groups and biochemical loci was higher than average for domestic horse breeds. For microsatellite loci, the variability of the large-type Zemaitukai and the Heavy Draught breeds also was high compared to the mean variation for domestic breeds; however, for the Zemaitukai breed, variation levels were very near the average for horses.  相似文献   

6.
The liberalization of European animal breeding legislation and an increasing diversity of equestrian sports have led to a constant rise in the number of horse breeds and breed registries. In addition to the trend towards more and smaller breed registries, there is another trend towards an international expansion of the bigger established sport horse breeds. Regional breeds, at least in smaller countries, may no longer be able to run an independent breeding programme. The typical horse breeder, in the future, will be a female and qualified in equestrian sports. Artificial insemination (AI) mainly with fresh or cooled-transported semen has become a major breeding tool, allowing breeders all over Europe to benefit from the best stallions of most breeds. New AI techniques such as low-dose insemination may remain restricted to individual stallions and also the interest of breeding programmes in sex determination of foals via semen sorting is limited. Embryo transfer and associated techniques, although allowed by most breeds, have not contributed significantly to genetic progress in European sport horses so far. A potential use of cloning may be to produce gonad-intact copies from geldings that have performed to a superior level. With a more open and international structure of horse breeding and increased use of AI, equine reproduction and biotechnology should be emphasized by veterinary curricula and continuing professional education programmes.  相似文献   

7.
Seven microsatellite markers were used to study genetic diversity of three Egyptian (Egyptian Baladi, Barki and Zaraibi) and two Italian (Maltese and Montefalcone) goat breeds. The microsatellites showed a high polymorphic information content (PIC) of more than 0.5 in most of the locus-breed combinations and indicated that the loci were useful in assessing within- and between-breed variability of domestic goat (Capra hircus). The expected heterozygosity of the breeds varied from 0.670 to 0.792. In the geographically wider distributed Egyptian Baladi breed there were indications for deviations from random breeding. Analysis of genetic distances and population structure grouped the three Egyptian goat breeds together, and separated them from the two Italian breeds. The studied Mediterranean breeds sampled from African and European populations seem to have differentiated from each other with only little genetic exchange between the geographically isolated populations.  相似文献   

8.
In 2002, it was discovered that several Cika cattle in the mountain areas of Slovenia had escaped the official policy of cross‐breeding. Here, we report a genetic characterization to assess their status as autochthonous breed. We compared genotypes for 14 microsatellite markers in 150 Cika cattle individuals with data from 16 Central European cattle breeds. We show that Cika cattle are genetically as diverse as other Eastern Alpine breeds, are more diverse than Austrian Simmental but less than the Balkan Busha cattle. STRUCTURE analysis showed Pinzgauer admixture in several individuals but also indicated a unique genetic identity for Cika. This analysis also allowed a selection of the most genetically pure Cika individuals as assessed by the panel of microsatellites. These original Cika cattle form an Eastern Alpine breed cluster together with Pinzgauer and Pustertaler cattle. Cika cattle should be considered as an authentic and valuable genetic resource, which offers clear opportunities for sustainable agriculture and landscape conservation in marginal and mountain areas.  相似文献   

9.
Genetic structure of Norwegian horse breeds   总被引：1，自引：0，他引：1  
The evaluation of the genetic structure of four native Norwegian horse breeds was investigated using 35 genetic markers including nine biochemical loci and 26 microsatellites. The proportion of genetic variation measured as heterozygosity and the number of alleles indicated high variation in Fjord Horse and Coldblooded Trotter, but somewhat reduced variation in Døle Horse. No clear signs of bottleneck effects were found in either of the breeds, but significant inbreeding estimates in Nordland/Lyngen Horse may indicate subdivision of this breed. Significant population differentiation was detected between all breeds, also between the recently diverged Døle Horse and Coldblooded Trotter. The principal component analysis supports the close genetic relationship between these two breeds.  相似文献   

10.
Coat color played an important role during domestication and formation of breeds. Livestock breeders often had special preferences for particular color phenotypes because they believed them to be associated with performance or fitness traits. Socio-cultural reasons might have had an influence on color selection as well. Recently genetic tests on DNA level got available to genotype in any individual horse for basic horse coat colors (chestnut, bay, black). In particular, hidden carriers of the recessive chestnut and black allele are recognizable with these tests. A sample of 162 Franches-Montagnes horses from Switzerland was genotyped for the alleles for chestnut and black. The analysis of allele frequencies revealed a high prevalence of the chestnut allele and a low frequency of the black allele in this population. Rare colors are in demand on the market. The statistical analysis of 1369 offspring from five stallions indicate, that darker shades of basic color phenotypes (dark chestnut, dark bay) follow a recessive mode of inheritance in the Franches-Montagnes horse breed.  相似文献   

11.
选用来源于牛和绵羊的27个微卫星DNA标记,对山东省4个地方山羊品种进行遗传多样性分析,通过计算等位基因频率、多态信息含量、不同标记的平均杂和度、总群体杂合度、亚群体杂合度、群体杂合度、基因分化系数、不同群体的F-统计量、基因流动数、不同群体间的基因流动个数和遗传距离并进行聚类分析,评估其种内变异和种间变异的关系,以群体平均杂合度、F-统计量和遗传分化系数为基础,结合四个山羊种群的实际生存状况,提出避免近交和种群间杂交符合山东山羊种群实际状况的保种模式。研究结果可为山东地方种质特性研究提供基础数据,为山东地方山羊种群的合理保护利用提供科学依据。  相似文献   

12.
Summer eczema, allergic dermatitis of the horse, was studied on 275 affected horses in Finland in 1997–2007. Features of the horses, clinical signs of the disease and owners'' opinions of aggravating factors were recorded. Differences, especially, between two of the native Scandinavian horse breeds, the Finnhorse and the Icelandic horse, were evaluated. The study was based on clinical examination and information from the owners. Of the horses, 50% were Finnhorses, 26% Icelandic horses and 24% consisted of different breeds of ponies and other horses. Of the Finnhorses, 76% had summer eczema by the age of 5 years, but in the Icelandic horses born in Finland the average age at onset was 7 years. The vast majority of the horses, 75%, had moderate clinical signs, while 16% showed severe and 9% mild. The severity of clinical signs did not depend on the duration of the disease nor was it related to the age at onset. The only linkage to severity was the breed of the horse or import from Iceland; New Forest ponies and imported Icelandic horses showed severe clinical signs significantly more often than Finnhorses. Of the owners, 38% regarded insects as the only aggravating factor, 24% mentioned several simultaneous factors, including grass fodder and sunlight, while 22% could not specify any. In Finland, a typical horse breed suffering from summer eczema is the Finnhorse and the characteristics of the disease are mainly uniform with the other breeds affected. Equine summer eczema seems to be aggravated by various combinations of environmental factors.  相似文献   

13.
A phenotypically interesting strain of cattle existed on the small island of Agersoe, on the west coast of Zealand, Denmark, in the beginning of the last decade. The cattle share a great resemblance to the extinct Danish breed, the Island cattle. The objective of this study was to genetically characterize the Agersoe cattle, using microsatellites, amplified fragment length polymorphism (AFLP) and mtDNA markers, and analyse the genetic variability within the breed and the genetic relationship to 14 European breeds with focus on the Red Danish and Jutland breed. The results show diversity in nuclear markers comparable to that of modern breeds and that the Agersoe cattle are separable from the two native breeds. The absence of inbreeding and the degree of genetic diversity are taken as a sign of recent admixture. The Agersoe cattle did not exhibit a consistent association with any of the European breeds. Several arguments based on this survey have been put forward in favour of characterizing the Agersoe cattle as being the last remnants of the Danish Island Cattle.  相似文献   

14.
Susceptibility to clinical scrapie is associated with polymorphisms in the prion protein (PrP) gene. The ARR allele reduces susceptibility to clinical disease caused by all known strains of the transmissible spongiform encephalopathy (TSE) agents. For the economically important German breeds of sheep the PrP allele frequencies are well known, but this paper presents representative genotyping results for 1526 sheep from two smaller milk sheep breeds and 2446 sheep from 14 mostly indigenous land sheep breeds. The ARR allele was detected in each breed but the breed-specific ARR frequencies varied between 1 and 63 per cent. In small populations with a very low ARR frequency the ARR allele could be lost by genetic drift. A simulation study was therefore made to examine the effects of different breeding schemes in populations of different sizes on attempts to select for the ARR allele in an endangered population. In breeds in which no homozygous rams are available the breeding strategy would depend on the number of heterozygous rams, and the genotyping and selection of suitable breeding ewes would reduce the time required to achieve a highly resistant population. In general, in all the breeds a selection programme to achieve 99 per cent ARR homozygous genotypes would be feasible in six to nine generations, depending on the initial allele frequencies. In small populations the inbreeding rate may increase if no specific mating plans are developed by the breeding organisations.  相似文献   

15.
In this study it was investigated whether the "Einsiedler" warmblood horse, a historically old horse population from central Switzerland (Abbey of Einsiedeln), is distinguishable from micellaneous horse breeds, using molecular genetic techniques. The breeding history of Einsiedler horses is characterised by systematic line breeding through the dams. Therefore, two Einsiedler dam lines (N = 28), going back to the middle of the 19th century according to pedigree entries, were the focus of the survey. Random samples of diverse warmblood horse populations, but also samples from more distinct types of horse breeds, served as comparison populations (N = 52).Variation in the mitochondrial genome appeared to be only partially informative to demarcate the studied horses, as horses of distinct breeds may share identical mtDNA sequence fragments. Both dam lines revealed haplotypes commonly found in Iberian horse breeds. This is to take as an indication on the genetic origin of Einsiedler horses. Furthermore, the Klima dam line held a homologous mtDNA sequence fragment with E. ferus przewalskii. Therefore, this seems to be a phylogenetically old haplotype. The analysis of microsatellite loci revealed that horses from the two Einsiedler dam lines were in fact distinguishable from more distinct types of horses, but not from closely related European warmblood horse breeds and English thoroughbred.  相似文献   

16.
In the last decades, several endangered breeds of livestock species have been re‐established effectively. However, the successful revival of the Dutch and Danish Landrace goats involved crossing with exotic breeds and the ancestry of the current populations is therefore not clear. We have generated genotypes for 27 FAO‐recommended microsatellites of these landraces and three phenotypically similar Nordic‐type landraces and compared these breeds with central European, Mediterranean and south‐west Asian goats. We found decreasing levels of genetic diversity with increasing distance from the south‐west Asian domestication site with a south‐east‐to‐north‐west cline that is clearly steeper than the Mediterranean east‐to‐west cline. In terms of genetic diversity, the Dutch Landrace comes next to the isolated Icelandic breed, which has an extremely low diversity. The Norwegian coastal goat and the Finnish and Icelandic landraces are clearly related. It appears that by a combination of mixed origin and a population bottleneck, the Dutch and Danish Land‐races are separated from the other breeds. However, the current Dutch and Danish populations with the multicoloured and long‐horned appearance effectively substitute for the original breed, illustrating that for conservation of cultural heritage, the phenotype of a breed is more relevant than pure ancestry and the genetic diversity of the original breed. More in general, we propose that for conservation, the retention of genetic diversity of an original breed and of the visual phenotype by which the breed is recognized and defined needs to be considered separately.  相似文献   

17.
The Friesian horse breed is a beautiful breed for showing, riding and driving. However, some clinical problems seem to have a higher incidence in the Friesian breed compared to other breeds and this raises suspicions that these clinical entities may have a genetic basis.  相似文献   

18.
Equine paranasal sinuses are susceptible to inflammation. Insufficient drainage through the nasal passages and meatus may lead to the accumulation of inspissated purulent discharge. Particularly in ponies, these anatomical structures are suspected to be relatively small. To date, there are no reports considering the morphology of nasal conchal bullae in small horse breeds such as Shetland ponies. The aim of the present study was to evaluate the size of the conchal bullae and the medial nasal conchae of Shetland ponies and their relation to the skull dimension using computed tomography. Reconstructed images of healthy adult heads of Shetland ponies were used. Linear skull measurements as well as two cranial indices of the head dimensions were taken. Length, width and height of the dorsal and ventral conchal bullae and the medial nasal conchae were measured in relation to the skull and compared with the data of skulls of large breed horses. The anatomical proportions of pony heads were characterized by a smaller cranial index and a greater nasal index than those of large breed horses. Shetland ponies showed a longer cranial length compared with the nasal length. Heads are consistently smaller, and the relationship of the bullae to the head length was also smaller than those measured in large breed horses. A negative correlation between the head and bullae size was found. In conclusion, this study suggests that Shetland ponies have distinguishing proportions of the head. These findings are relevant for clinical examination and surgical treatment of equine sinus disease in those breeds.  相似文献   

19.
A common female founder individual of the Portuguese horse breeds Sorraia and Lusitano was found while conducting research on the variation of the Lusitano mitochondrial DNA lineages in relation to studbook information. We obtained 416‐bp control region sequences from 16 descendents of a female Sorraia founder (Pomba) still represented in the living population of the Lusitano, according to the most recent edition of this breed's studbook. The same haplotype was found for all analysed samples and belongs to the haplogroup described by several authors as having predominantly Iberian, South American and North African haplotypes bringing new insights on the relationship between the Sorraia and the other Iberian breeds. This work illustrates how weak the boundary of breed establishment can be, especially at the same geographical region. Using the same founders in different breeds is surely one of the explanations to frequently shared haplotypes among recent breeds, resulting in a lack of consistency between mtDNA sequences and breeds and/or geographical regions.  相似文献   

20.
Genetic variability of the dog breed Hanoverian Hound was analysed using a set of 16 microsatellites. The sample of 92 dogs was representative for the total current population [n = 334, inbreeding coefficient 9.2%, relationship coefficient 11.2%] with respect to the level and distribution of the inbreeding and relationship coefficients. All microsatellites used were in Hardy–Weinberg equilibrium. The average number of alleles was 6.4. The average observed heterozygosity (HO) was slightly higher than the expected heterozygosity (HE). Dinucleotide microsatellites exhibited lower polymorphism information content (PIC) than tetranucleotide microsatellites (0.52 versus 0.66). The average PIC was 0.61. The individual inbreeding coefficient was negatively related to the average HO of all microsatellites, whereas the proportion of genes from introducing of Hanoverian Hounds from abroad showed no relationships to HO. We found that the genetic variability in the Hanoverian Hounds analysed here was unexpectedly higher than that previously published for dog breeds of similar population size. Even in dog breeds of larger population size heterogyzosity was seldom higher than that observed here. The rather high genetic variability as quantified by polymorphic microsatellites in Hanoverian Hounds may be due to a large genetic variation in the founder animals of this breed and to the fact that this genetic diversity could be maintained despite genetic bottlenecks experienced by this breed in the 1920s and 1950s and despite the presence of high inbreeding and relationship coefficients for more than 50 years.  相似文献   

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