Genetic variations in blood proteins within and between Spanish dairy sheep breeds

Eleven flocks of three Spanish sheep breeds have been studied: four Churra, four Lacha and three Manchega. Genetic variations between flocks of the same and different breeds have been analysed, using eight genetic blood systems and a wide range of statistical methods. The results show that the Churra, Lacha and Manchega breeds present significant differences between each other. Significant intraracial variations have been observed in Churras and Lachas, although they were almost non-existent in Manchegas. In some cases the genetic distances between flocks of the same breed were greater than the distances between flocks of different breeds. The data indicate that the closest breeds genetically are Lacha and Manchega.     

Genetic relationships between seven Spanish native breeds of cattle

Summary. Ten genetic markers were studied in seven Spanish native cattle breeds, using a total of 725 animals. Of the ten, two were found to be monomorphic in all seven breeds. The genetic relationships of the seven breeds are estimated by three different genetic-statistical methods (genetic distances, main coordinate analysis and cluster analysis), which indicate three clearly distinct groups of populations: one where the Cárdena Andaluza and Alistana Sanabresa are very closely related, one comprising Sayaguesa, Morucha, Asturiana de los Valles and Asturiana de la Montaña cattle, and a third, genetically distant from the other two, comprising only Blanca Cacereña. The dendrogram drawn from the genetic distances matrix would seem to imply that the seven breeds are descended from different ancestors.     

Genetic structure and admixture in sheep from terminal breeds in the United States

Selection for performance in diverse production settings has resulted in variation across sheep breeds worldwide. Although sheep are an important species to the United States, the current genetic relationship among many terminal sire breeds is not well characterized. Suffolk, Hampshire, Shropshire and Oxford (terminal) and Rambouillet (dual purpose) sheep (n = 248) sampled from different flocks were genotyped using the Applied Biosystems Axiom Ovine Genotyping Array (50K), and additional Shropshire sheep (n = 26) using the Illumina Ovine SNP50 BeadChip. Relationships were investigated by calculating observed heterozygosity, inbreeding coefficients, eigenvalues, pairwise Wright’s F_ST estimates and an identity by state matrix. The mean observed heterozygosity for each breed ranged from 0.30 to 0.35 and was consistent with data reported in other US and Australian sheep. Suffolk from two different regions of the United States (Midwest and West) clustered separately in eigenvalue plots and the rectangular cladogram. Further, divergence was detected between Suffolk from different regions with Wright’s F_ST estimate. Shropshire animals showed the greatest divergence from other terminal breeds in this study. Admixture between breeds was examined using admixture , and based on cross-validation estimates, the best fit number of populations (clusters) was K = 6. The greatest admixture was observed within Hampshire, Suffolk, and Shropshire breeds. When plotting eigenvalues, US terminal breeds clustered separately in comparison with sheep from other locations of the world. Understanding the genetic relationships between terminal sire breeds in sheep will inform us about the potential applicability of markers derived in one breed to other breeds based on relatedness.     

Microsatellite analysis to estimate genetic relationships among five bulgarian sheep breeds

Herein, genetic relationships among five breeds of Bulgarian sheep were estimated using microsatellite markers. The total number of alleles identified was 226 at the 16 loci examined. D(A) distance values were used for phylogenetic tree construction with the UPGMA algorithm. The two Tsigai and two Maritza populations were found to be geneticallvery closely related to each other y (0.198, and 0.258 respectively). The Pleven Black Head population was distinct from the other four. These results could be useful for preserving genes in these breeds, thereby ensuring their preservation in Bulgaria.     

Genetic diversity in nine native Turkish sheep breeds based on microsatellite analysis

The genetic variability of 204 sheep from nine breeds (Awassi, Çine Çapar?, Karaka?, Karya, Karayaka, Morkaraman, Norduz, Sak?z and Tuj) growing in four different regions (western, northern, eastern and south‐eastern Anatolia) was assessed using 18 microsatellite loci. High mean number of alleles, allelic richness and factorial correspondence analysis showed the degree of admixture between native sheep breeds of Turkey. The Karya and Çine Çapar? breeds were observed as the most distinct of the breeds, and possible introgressions were detected in other breeds. It was found that 8.9% of genetic variation resulted from the difference between the populations. The genetic variation in Turkish breeds was not much higher than that of European breeds, which might be a consequence of the recent sharp decrease in sheep numbers.     

Genetic variation in the blood of llamas, Llama glama, and alpacas, Llama pacos

Blood samples of llamas and alpacas were typed using haemolytic, electrophoretic and isoelectric focusing procedures to assay polymorphism at 13 loci. Blood group variation was assessed using six antibody specificities produced by allo- and heteroimmunizations. Two red cell factors (A and B) behave as autosomal, codominant alleles at a closed A locus. The other four factors (C, D, E and F) behave as autosomal, dominant traits. Biochemical variation was found for red cell enzymes catalase, phosphogluconate dehydrogenase, glucose phosphate isomerase and for plasma proteins transferrin and post-albumin. No variants were found for haemoglobin, phosphoglucomutase and albumin. Estimates of probability of exclusion were 0.883 for llamas and 0.681 for alpacas, which are adequate initial levels of efficacy for purposes of parentage verification. Preliminary estimate of Nei's genetic distance measure (D) suggests that llamas and alpacas are more likely related as subspecies than as separate species.     

Genetic diversity and differentiation of 12 eastern Adriatic and western Dinaric native sheep breeds using microsatellites

Nuclear genetic diversity and differentiation of 341 sheep belonging to 12 sheep breeds from Croatia and Bosnia and Herzegovina were examined. The aim of the study was to provide the understanding of the genetic structure and variability of the analysed pramenka sheep populations, and to give indications for conservation strategies based on the population diversity and structure information. The genetic variation of the sheep populations, examined at the nuclear level using 27 microsatellite loci, revealed considerable levels of genetic diversity, similar to the diversity found in other European indigenous low-production sheep breeds. Population-specific alleles were detected at most loci and in breeds analysed. The observed heterozygosity ranged from 0.643 (in Lika pramenka) to 0.743 (in Vlasic pramenka), and the expected heterozygosity ranged from 0.646 (in Lika pramenka) to 0.756 (in Dalmatian pramenka). Significant inbreeding coefficients were found for half of the populations studied and ranged from 0.040 (Pag island sheep) to 0.091 (Kupres pramenka). Moderate genetic differentiation was found between the studied sheep populations. The total genetic variability observed between different populations was 5.29%, whereas 94.71% of the variation was found within populations. Cres island sheep, Lika pramenka and Istrian sheep were identified as the most distinct populations, which was confirmed by the factorial analysis of correspondence and supported through a bootstrapping adjustment to correct for the difference in the sample sizes. The population structure analysis distinguished 12 clusters for the 12 sheep breeds analysed. However, the cluster differentiation was low for Dalmatian, Vlasic, Stolac and Krk pramenka. This systematic study identified Lika pramenka and Rab island sheep as those with the lowest diversity, whereas Istrian sheep and Pag island sheep had the highest. Conservation actions are proposed for Istrian, Rab and Cres island sheep, Lika and Kupres pramenka because of high estimated coefficients of inbreeding.     

Genetic relationships between 14 native Spanish breeds of goat

Summary. The genetic distances separating 14 Spanish goat breeds are calculated from gene frequency data of 14 genetic blood markers (GSH, Ke, Hb, Dia, Ct, MDH, CA, X, NP, Alp, Am, Cp, Tf and Al).
Working from the matrix of Nei's genetic distances we drew a dendrogram demonstrating a great genetic similarity among populations from Negra Serrana, Zamorana, Guadarrama, Retinta, Blanca Andaluza, Berciana and Pirenaica on one hand; and Canaria, Murciana, Blanca Celtibérica, Verata, Palmera, Malaguena and Granadina on the other.
We discuss the similarities and differences within our classification using gene frequency data of the blood genetic markers studied, and classifications based chiefly on morphological and production data.     

Genetic relationships among Spanish sheep using microsatellites

Five indigenous Spanish breeds of sheep, Churra, Latxa, Manchega, Rasa–Aragonesa and Merino, with Awassi sheep as a reference breed were genotyped for 19 DNA microsatellites. Allele frequencies and mean heterozygosities revealed the greatest genetic variation in Merino sheep and the lowest in Awassis. Differences in variability were not great in the other breeds studied. The dendrograms obtained based on genetic distances showed a large differentiation between Awassi sheep and the Spanish breeds, as was to be expected from their distinct genetic origin. Merinos appeared separated from the other four breeds, of which, according to a classification based on the fleece characteristics, Churra and Latxa belong to the churro type and Manchega and Rasa–Aragonesa to the so called entrefino type, though no clear separation was evident between the two types. These results suggest that morphological data alone are insufficient for determining relationships between breeds and that studies involving genetic markers may be of great assistance.     

Genetic diversity and subdivision of 57 European and Middle-Eastern sheep breeds

The population structure and genetic diversity of 57 European and Middle Eastern marginal and cosmopolitan sheep breeds from 15 countries were analysed by typing 31 microsatellite markers. Mean unbiased expected heterozygosities ranged from 0.63 in British Exmoor Horn to 0.77 in Albanian Ruda. South-eastern European and Middle-Eastern sheep breeds were significantly more variable than northwestern and western European breeds. An overall heterozygote deficiency (f) across all loci was observed (P < 0.001), while genetic differentiation (theta) was 5.7%. Principal component analysis and Bayesian model-based clustering indicate a south-east to north-west cline, but also revealed distinct groups of Middle-Eastern fat-tailed sheep, south-eastern European sheep and north-western/western European sheep. Within the last group, two less-distinct clusters comprised the Merino-type and Alpine breeds respectively. The incomplete demarcations of most clusters probably reflects cross-breeding and/or upgrading.     

Genetic relationships among Turkish sheep

Genetic relationships among Turkish sheep breeds were analysed on the basis of 30 microsatellite markers. Phylogenetic analyses based on the estimation of genetic distances revealed the closest relationships for the Akkaraman, Morkaraman and Tuj breeds, which were clearly differentiated from the others in the dendrogram. Our pattern was completely confirmed by results from the Factorial Correspondence Analysis. All the results described analysing either population parameters or individuals revealed a clear separation between the fat-tailed group and the others. These results, based on nuclear DNA, are discussed along with those already reported for these breeds through the investigation of mitochondrial DNA, which had revealed the invaluable significance of the genetic background of these Turkish sheep.     

Evaluation of linkage between the R-O-i and C blood group systems in sheep

Linkage between the C and I blood group loci in sheep was demonstrated by lod score analysis of data from double backcross matings. The recombination frequency between the I locus and the gene coding for the Cb red cell antigen was estimated to be 0.09 with a standard error of 0.04.     

中国7个地方绵羊品遗传多样性的微卫星分析

利用26个微卫星标记分析了中国7个地方绵羊（Ovis aries）品种的遗传多样性。通过计算基因频率,平均杂合度（H）、多态信息含量（PIC）及有效等位基因数（Ne）,并根据Nei氏标准遗传距离,利用UPGMA法进行了聚类分析,评估其种内遗传变异和品种间遗传关系。结果表明：26个微卫星位点共检测到278个等位基因,Ne在2.1288-13.3924之间;26个位点均为高度多态位点,PIC在0.6628-0.8712之间,聚类分析表明哈萨克羊、阿勒泰羊和巴音布鲁克羊遗传关系最近;然后与白藏羊,黑藏羊聚为一类,湖羊和晋中羊聚为一类,各绵羊各种的聚类关系与其来源,育成史及地理分布基本一致。     

Relationships between rare breeds of sheep in the Netherlands as based on blood-typing

Genetic distances between seven Dutch rare breeds of sheep were established as based upon blood groups and biochemical polymorphisms, A rather close relationship was observed between three breeds of heath sheep (Drente, Veluwe and Kempen) and the Schoonebeker sheep, The Mergelland sheep was less related to this cluster, The largest distances were between Friesian sheep and Black Blaze sheep and all others.     

Genetic relationships among European cattle breeds

Genetic relationships among 37 European cattle breeds were investigated using blood group and serum protein polymorphisms. The 18 859 animals included in the study represented a random sample from pedigree populations in the UK. Within-breed variation was estimated by average heterozygosity and number of alleles observed, and breed relationships were evaluated by genetic distance. Standard errors of the heterozygosity, number of alleles and genetic distance were obtained by bootstrapping. The significance of breed differences was tested using an exact test of differentiation. French, Italian and Channel Island breeds were found to have generally higher heterozygosities and a greater number of alleles than breeds from mainland Britain and North Europe. Genetic distances ranged between 0·011 (±0·005) and 0·309 (±0·071). Two major breed groups were identified; a group of French, Italian and Channel Island breeds together with the Simmental and Gelbvieh, and a second group consisting of the mainland British and North European breeds. The exact test of breed differentiation showed all breeds to be significantly different from one another ( P < 0·0001). Overall relationships among breeds reflected their geographical origin and common ancestry rather than the agricultural use for which the breeds have been selected.     

Genetic characterization and breed assignment in five Italian sheep breeds using microsatellite markers

The knowledge of the genetic relationship and admixture among neighbouring populations is crucial for conservation efforts. The aim of this study was to analyse the genetic diversity of five Italian sheep breeds (Appenninica, Garfagnina Bianca, Massese, Pomarancina and Zerasca) using a panel of 24 microsatellite markers. Blood samples from 226 individuals belonging to the aforementioned populations were obtained and genotyped. All the investigated breeds showed a significant heterozygote deficiency caused by the high level of inbreeding indicated also by the high level of F_IS (0.146). Genetic differentiation between breeds was moderate (F_ST = 0.05) but significant and the individuals could be assigned to their breeds with an high success rate even if the inter-individual distances showed that few animals clustered separately from the other individuals of the same breed, especially for Pomarancina breed. The genetic distances reflect the historical knowledge of these breeds and some patterns of ancestral and recent gene flow between neighbour populations arise. The clustering analysis detects the presence of six clusters. Massese and Zerasca breeds were grouped together as well as Appenninica and Pomarancina with the latter forming two distinct clusters equally represented. The formation of this last breed is occurred with the absorption of individuals of the Appenninica breed and the gene flow probably continued in these recent years allowing the presence of a population substructure for Pomarancina breed. Such substructure supports the high level of heterozygote deficiency found for this breed despite the relatively high population size. The five populations analysed presented some genetic similarities but a clear uniqueness of the populations has been showed for almost all of them. Special attention to monitor genetic variability and to organize mating plans should be given especially for the three endangered breeds.     

中国绵羊起源、进化和遗传多样性研究进展

中国地方绵羊品种资源丰富,部分品种具有繁殖力高、毛皮品质好、多角、多乳头、大尾脂、抗逆性强等独特性状,这些遗传资源引起了学者们对其进行深入研究的兴趣,但目前仍然存在绵羊起源问题的争议,缺乏对我国绵羊的遗传多样性进行全面系统研究等问题。本文综述了绵羊起源、品种分化等方面的研究进展,并从父系、母系、常染色体分子标记等不同层面介绍了中国绵羊遗传多样性的研究概况,为中国绵羊遗传资源的保护和利用、绵羊新品种(系)的培育以及我国绵羊产业良性发展提供参考。     

Blood groups and protein polymorphisms in five goat breeds (Capra hircus)

Data on allele frequencies at six red cell blood group systems and three blood protein polymorphic loci in five goat breeds are reported. Two blood proteins, albumin and carbonic anhy-drase, were not found to be polymorphic. The B blood group system of goats, like its homologue in cattle and sheep, is highly complex. At least 44 B phenogroups (haplotypes) have been distinguished in this study. Based on the variation in allele frequencies between breeds, genetic distances were calculated. The distances estimated by four different methods were in close agreement with data from the history and geographic origins of the breeds examined.     

Genetic diversity of two native sheep breeds by genome-wide analysis of single nucleotide polymorphisms

Wallachian and Sumava sheep are autochthonous breeds that have undergone a significant bottleneck effect and subsequent restoration efforts. The first objective of this study was to evaluate the degree of genetic variability of both breeds and, therefore, the current management of the breeding. The second was to determine whether these two breeds still retain their genetic uniqueness in relation to each other and other breeds, despite regenerative interventions. Our data consisted of 48 individuals of Sumava and 37 individuals of Wallachian sheep. The comparison data contained 25 other breeds (primarily European) from the HapMap dataset generated by the International Sheep Genomics Consortium. When comparing all 27 breeds, the Czech breeds clustered with 15 other breeds and formed a single branch with them according to Nei's distances. At the same time, however, the clusters of both breeds were integral and easily distinguishable from the others when displayed with principal component analysis (PCA). Population substructure analysis did not show any common genetic ancestry of the Czech national breeds and breeds used for regeneration or, eventually, breeds whose ancestral population was used for regeneration. The average values of F_ST were higher in Wallachian sheep (F_ST = 0.14) than in Sumava sheep (F_ST = 0.08). The linkage disequilibrium (LD) extension per autosome was higher in Wallachian than in Sumava sheep. Consequently, the N_e estimates five generations ago were 68 for Sumava versus 34 for Wallachian sheep. Both native Czech breeds exhibit a wide range of inbreeding based on the excess of homozygosity (F_HOM) among individuals, from ?0.04 to 0.16 in Sumava and from ?0.13 to 0.12 in Wallachian. Average inbreeding based on runs of homozygosity was 0.21 in Sumava and 0.27 in Wallachian. Most detected runs of homozygosity (ROH) were less than 5 Mb long for both breeds. ROH segments longer than 15 Mb were absent in Wallachian sheep. Concerning putative selection signatures, a total of 471 candidate genes in Wallachian sheep within 11 hotspots and 653 genes within 13 hotspots in Sumava sheep were identified. Czech breeds appear to be well differentiated from each other and other European breeds. Their genetic diversity is low, especially in the case of the Wallachian breed. Sumava is not so threatened by low diversity but has a larger share of the non-native gene pool.