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1.
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.  相似文献   

2.
We tested the use of biallelic Amplified fragment length polymorphism (AFLP) polymorphisms for the estimation of relative genetic distances of cattle individuals within or across breeds. An allele permutation procedure was developed to estimate the stochastic variation of the genetic distance that is inherent to a given dataset. In a panel of 47 Holstein-Friesian cattle analysed with 248 polymorphic markers, the average genetic distance of bulls selected for breeding was slightly lower than the distance of the cows. The observed standard deviation (SD) of the distance indicated genetic subdivision, which for the bulls was explained by variation in the additive relationship derived from herdbook data. Animals from three different breeds, the highly selected Holstein-Friesian, the Italian Brown and the historic Maremmana, were compared on the basis of 106 polymorphic markers. No breed-specific fragments were observed. The mean pair-wise genetic distance within breeds was 85% of the value across breeds, but principal coordinates analysis clustered the animals according to their breed of origin. Calculation of distances between the breeds indicated a relatively divergent position of the Maremmana, relative to the two other breeds. However, biallelic markers indicate that the process of breed formation had only a limited effect on the diversity at marker loci.  相似文献   

3.
Chianina and Maremmana breeds play an important role in the Italian cattle meat market. The Chianina breed is an ancient breed principally raised for draught. Now this breed is the worldwide recognized producer of top quality beef, tasteful and tender, specifically the famous “Florentine steak”. The Maremmana characterized by a massive skeletal structure, is a rustic cattle breed selected for adaptability to the marshy land of the Maremma region. We used a high throughput mRNA sequencing to analyze gene expression in muscle tissues of two Italian cattle breeds, Maremmana (MM) and Chianina (CN) with different selection history. We aim to examine the specific genetic contribution of each breed to meat production and quality, comparing the skeletal muscle tissue from Maremmana and Chianina. Most of the differentially expressed genes were grouped in the Glycolysis/Gluconeogenesis pathways. The rate and the extent of post-mortem energy metabolism have a critical effect on the conversion of muscle to meat. Furthermore, we aim at discovering the differences in nucleotide variation between the two breeds which might be attributable to the different history of selection/divergence. In this work we could emphasize the involvement of pathways of post-mortem energy metabolism. Moreover, we detected a collection of coding SNPs which could offer new genomic resources to improve phenotypic selection in livestock breeding program.  相似文献   

4.
The gene pools of beef cattle breeds bred in Russia were characterized on the basis of inter simple sequence repeat DNA analysis (ISSR analysis). Samples of Aberdeen Angus, Kalmyk, and Kazakh Whitehead breeds from Russia, as well as of Hereford breed, hybrids of Kazakh Whitehead and Hereford breeds, and Kazakh Whitehead breed from the Republic of Kazakhstan, were examined. In the examined breeds, 27 AG-ISSR fragments were identified, 25 of which were polymorphic. The examined breeds were different both in the fragment profiles (the presence/absence of individual ISSR fragments) and in their frequencies. It was demonstrated that the hybrid animals lacked some ISSR fragments that were present with high frequencies in parental forms, suggesting considerable genome rearrangement in the hybrid animals (at the regions of microsatellite localization) in crossings of the individuals from different breeds. The level of genetic diversity in Russian beef breeds was consistent with the values typical of farmed populations (breeds). The genetic diversity parameters assessed by applying Nei’s gene diversity index and the Shannon index varied from 0.0218 to 0.0605 and from 0.0225 to 0.0819, respectively. The highest Shannon index value was detected in the Kalmyk breed (0.0837) and Kazakh Whitehead breed from Russia (0.0819), and the highest level of Nei’s gene diversity index was found in the Kalmyk breed (0.0562) and in both populations of the Kazakh Whitehead breed (0.0509 and 0.0605). The high level of genetic similarity (according to Nei) was revealed between Russian beef cattle breeds and Hereford cattle: 0.839 (for the Kazakh Whitehead breed from Russia) and 0.769 (for the Kalmyk breed).  相似文献   

5.
We estimated the genetic relationships between the endangered German Pustertaler-Sprinzen cattle breed and the Pinzgauer, Vosges and Simmental breeds--decided upon after consultation of the available historical literature. Within-breed diversity of the four breeds was also assessed. Twenty microsatellite markers were amplified in 27-50 unrelated individuals from populations of each breed. Within-breed variation was estimated from average heterozygosity values and mean number of alleles. Breed relationships were evaluated by genetic distance and a neighbour-joining tree was calculated from these estimates. Bootstrap resampling of loci tested the robustness of the tree topology obtained. A tree was also constructed from distance matrices using individual animals as operational taxonomic units. From both the average heterozygosity values and mean number of alleles calculated, the Pustertaler breed appears to be no more genetically impoverished than the other breeds analysed. The breed tree showed an 85% support for the Pustertaler-Pinzgauer grouping, and this result is echoed in the genetic distance values and allele-sharing individual tree.  相似文献   

6.
The present study estimates genetic variability with a set of 25 microsatellite markers in a random sample of 50 animals of Tharparkar breed of Indian zebu (Bos indicus) cattle. Tharparkar is a dual-purpose breed, valued for its milk as well as draught utility, and is adapted to the inhospitable Thar desert conditions of Rajasthan typified by summer temperature hovering above 50 degrees C, sparse rainfall and vegetation, and scarcity of even drinking water. The observed number of alleles ranged from 4 (ETH3, ILSTS030, INRA5, INRA63 and MM8) to 11 (HEL9 and ILSTS034), with allelic diversity (average number of observed alleles per locus) of 6.20. Observed and expected heterozygosity ranged from 0.25 (INRA63) to 0.77 (ETH10), and from 0.51 (HEL5 and HAUT27) to 0.88 (HEL9) respectively. Wide range of genetic variability supported the utility of these microsatellite loci in measurement of genetic diversity indices in other Indian cattle breeds too. Various average genetic variability measures, namely allele diversity (6.20), observed heterozygosity (0.57), expected heterozygosity (0.67) and mean polymorphism information content (0.60) values showed substantial within-breed genetic variability in this major breed of Rajasthan, despite accumulated inbreeding as reflected by high average inbreeding coefficient (F(IS) = 0.39). The Tharparkar population has not experienced a bottleneck in the recent past.  相似文献   

7.
Contrary to highly selected commercial breeds, indigenous domestic breeds are composed of semi-wild or feral populations subjected to reduced levels of artificial selection. As a consequence, many of these breeds have become locally adapted to a wide range of environments, showing high levels of phenotypic variability and increased fitness under natural conditions. Genetic analyses of three loci associated with milk production (alpha(S1)-casein, kappa-casein and prolactin) and the locus BoLA-DRB3 of the major histocompatibility complex indicated that the Argentinean Creole cattle (ACC), an indigenous breed from South America, maintains high levels of genetic diversity and population structure. In contrast to the commercial Holstein breed, the ACC showed considerable variation in heterozygosity (H(e)) and allelic diversity (A) across populations. As expected, bi-allelic markers showed extensive variation in He whereas the highly polymorphic BoLA-DRB3 showed substantial variation in A, with individual populations having 39-74% of the total number of alleles characterized for the breed. An analysis of molecular variance (AMOVA) of nine populations throughout the distribution range of the ACC revealed that 91.9-94.7% of the total observed variance was explained by differences within populations whereas 5.3-8.1% was the result of differences among populations. In addition, the ACC breed consistently showed higher levels of genetic differentiation among populations than Holstein. Results from this study emphasize the importance of population genetic structure within domestic breeds as an essential component of genetic diversity and suggest that indigenous breeds may be considered important reservoirs of genetic diversity for commercial domestic species.  相似文献   

8.
The Eastern European Grey cattle are regarded as the direct descendants of the aurochs (Bos taurus primigenius). Nowadays in Romania, less than 100 Grey animals are being reared and included in the national gene reserve. We examined the genetic diversity among Romanian Grey, Brown, Spotted and Black and White cattle breeds, with a particular focus on Romanian Grey through the use of (i) 11 bovine specific microsatellite markers on 83 animals and (ii) 638 bp length of mitochondrial DNA (mtDNA) D-loop region sequence data from a total of 81 animals. Both microsatellite and mtDNA analysis revealed a high level of genetic variation in the studied breeds. In Romanian Grey a total of 100 alleles were found, the mean number of observed alleles per locus was 9.091; the average observed heterozygosity was 0.940; the Wright’s fixation index (FIS) was negative (-0.189) and indicates that there is no inbreeding and no selection pressure. MtDNA analysis revealed 52 haplotypes with 67 variable sites among the Romanian cattle breeds without any insertion or deletion. Haplotype diversity was 0.980 ± 0.007 and ranged from 0.883 ± 0.056 (Brown) to 0.990 ± 0.028 (Spotted and Black and White). The highest genetic variability of the mtDNA was recorded in the Grey breed, where 18 haplotypes were identified. The most frequent mtDNA D-loop region belonged to T3 haplogroup (80.247%), which was found across all studied breeds, while T2 haplotypes (16.049%) was only found in Grey, Spotted and Black and White genotypes. The T1 haplotypes (3.704%) were found in the Grey and Spotted. The current results contribute to the general knowledge on genetic diversity found in Eastern European cattle breeds and could prove a valuable tool for the conservation efforts of animal genetic resources (FAnGR).  相似文献   

9.
Preservation of rare genetic stocks requires assessment of within-population genetic diversity and between-population differentiation to make inferences on their degree of uniqueness. A total of 194 Tuscan cattle (44 Calvana, 35 Chianina, 25 Garfagnina, 31 Maremmana, 31 Mucca Pisana and 28 Pontremolese) individuals were genotyped for 34 microsatellite markers. Moreover, 56 samples belonging to Argentinean Creole and Asturiana de la Montaña cattle breeds were used as an outgroup. Genetic diversity was quantified in terms of molecular coancestry and allelic richness. STRUCTURE analyses showed that the Tuscan breeds have well-differentiated genetic backgrounds, except for the Calvana and Chianina breeds, which share the same genetic ancestry. The between-breed Nei's minimum distance (Dm) matrices showed that the pair Calvana–Chianina was less differentiated (0.049 ± 0.006). The endangered Tuscan breeds (Calvana, Garfagnina, Mucca Pisana and Pontremolese) made null or negative contributions to diversity, except for the Mucca Pisana contribution to allelic richness (CT = 1.8%). The Calvana breed made null or negative within-breed contributions (f¯W = 0.0%; CW = −0.4%). The Garfagnina and Pontremolese breeds made positive contributions to between-breed diversity but negative and high within-breed contributions, thus suggesting population bottleneck with allelic losses and increase of homozygosity in the population. Exclusion of the four endangered Tuscan cattle breeds did not result in losses in genetic diversity (f¯T = −0.7%; CT = −1.2%), whereas exclusion of the non-endangered breeds (Chianina and Maremmana) did (f¯T = 2.1%; CT = 3.9%); the simple exclusion of the Calvana breed from the former group led to losses in genetic diversity (f¯T = 0.47%; CT = 2.34%), indicating a diverse significance for this breed. We showed how quantifying both within-population diversity and between-population differentiation in terms of allelic frequencies and allelic richness provides different and complementary information on the genetic backgrounds assessed and may help to implement priorities and strategies for conservation in livestock.  相似文献   

10.
Genetic relationships among European cattle breeds   总被引:1,自引:0,他引:1  
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.  相似文献   

11.
Information about genetic diversity and population structure among goat breeds is essential for genetic improvement, understanding of environmental adaptation as well as utilization and conservation of goat breeds. Here, we measured genetic diversity and population structure in multiple Chinese goat populations, namely, Nanjiang, Qinggeda, Arbas Cashmere, Jining Grey, Luoping Yellow and Guangfeng goats. A total of 193 individuals were genotyped for about 47 401 autosomal single nucleotide polymorphisms (SNPs). We found a high proportion of informative SNPs, ranging from 69.5% in the Luoping Yellow to 93.9% in the Jining Grey goat breeds with an average mean of 84.7%. Diversity, as measured by expected heterozygosity, ranged from 0.371 in Luoping Yellow to 0.405 in Jining Grey goat populations. The average estimated pair‐wise genetic differentiation (FST) among the populations was 8.6%, ranging from 0.2% to 16% and indicating low to moderate genetic differentiation. Principal component analysis, genetic structure and phylogenetic tree analysis revealed a clustering of six Chinese goat populations according to geographic distribution. The results from this study can contribute valuable genetic information and can properly assist with within‐breed diversity, which provides a good opportunity for sustainable utilization of and maintenance of genetic resource improvements in the Chinese goat populations.  相似文献   

12.
Genetic diversity in Swiss goat breeds based on microsatellite analysis   总被引:18,自引:0,他引:18  
Genetic diversity in eight Swiss goat breeds was estimated using PCR amplification of 20 bovine microsatellites on 20-40 unrelated animals per breed. In addition, the Creole breed from the Caribbean and samples of Ibex and Bezoar goat were included. A total of 352 animals were tested. The bovine microsatellites chosen amplified well in goat. The average heterozygosity within population was higher in domestic goat (0.51-0.58) than in Ibex (0.17) and Bezoar goat (0.19). Twenty-seven per cent of the genetic diversity in the total population could be attributed to differences between the populations. However, with the exclusion of Ibex from the total population, this proportion dropped to 17%. Principal component analysis showed that all Swiss goat breeds are closely related, whereas the Creole breed, Ibex and Bezoar goat are clearly distinct from all eight Swiss breeds.  相似文献   

13.
Indian goat breeds are recognized as an invaluable component of the world's goat genetic resources. Microsatellite pairs were chosen from the list suggested by International Society for Animal Genetics (ISAG) and amplified in two multiplexes (Set-I: 7 microsatellites and Set-II: 11 microsatellites) for automated fluorescence genotyping to assess bottleneck and analyze genetic variability and genetic distances within and between three goat breeds viz. Zalawadi, Gohilwadi and Surti. The observed number of alleles ranged from 4 (Oar JMP-29) to 15 (ILSTS-030 and -034) with a total of 178 alleles and mean of 9.89 alleles across the three breeds. The overall heterozygosity, PIC and Shannon index values were 0.61, 0.60 and 1.50 indicating high genetic diversity. The maximum observed heterozygosity was found in Gohilwadi and minimum in Surti goat breed. The Nei's standard genetic distance was minimum between Zalawadi and Gohilwadi, and maximum between Gohilwadi and Surti. Non-significant heterozygote excess on the basis of IAM, TPM and SMM models, as revealed from Wilcoxon sign-rank tests, along with a normal ‘L’-shaped distribution of mode-shift test, indicated no bottleneck in Zalawadi and Gohilwadi goat populations, whereas mild bottleneck in the recent past for Surti breed. This research on goat genetic diversity in Gujarat state provides valuable information on Zalawadi, Gohilwadi and Surti goat genetic resources, and will assist in developing a national plan for the conservation and utilization of indigenous goat breeds.  相似文献   

14.
中国黄牛起源复杂,我国地方黄牛群体不同品种在毛色、形态外貌、细胞遗传学、血液蛋白座位分析均表现出多样性。计算我国黄牛群体6个毛色座位平均杂合度和6个血液蛋白座位平均杂合度分别为0.3144和0.4873,表明我国地方黄牛群体的遗传多样性非常丰富。计算我国黄牛群体的6个毛色座位和6个血液蛋白座位的基因分化系数分别为0.3404和0.095,表明我国黄牛群体毛色差异中有34.04%是由品种间的差异造成的。血液蛋白的多态性有9.5%是由品种间的差异造成的。我国黄牛群体的遗传多样性主要来自品种内的遗传多样性。保存我国黄牛品种资源多样性不仅要从整个中国黄牛群体上考虑,而且要针对每个品种(或类群)进行保种。  相似文献   

15.
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 FIS value of 0.1149, indicating slight level of inbreeding in Vechur population. Overall, FST 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.  相似文献   

16.
Temporal changes in genetic variation within and between 13 North European cattle breeds were evaluated using erythrocyte antigen systems and transferrin protein as genetic markers. Current data on allele frequency distributions of markers in large commercial and smaller endangered native cattle breeds were compared to data published during 1956 to 1975. Intrabreed genetic variation was quantified by conventional parameters (e.g. heterozygosity, average number of alleles per locus) and migration by the effective migration rate. The neighbour-joining dendrogram of relationships between old and present cattle populations was constructed using Nei's standard genetic distance. Variance effective population size was estimated from changes in allele frequencies over time. Comparison of old and new data indicated some significant changes in allele frequencies. In six of the breeds, a few low-frequency alleles in the old data were absent in the present samples. Heterozygosity remained stable in most breeds. The harmonic means for variance effective population size ranged between 30 and 257. Current results indicate that despite marked declines in total population sizes, North European native cattle breeds have retained a reasonably high genetic diversity. However, their genes contribute less than previously to genetic variation of Nordic production breeds. Commercial breeds do not appear to have a larger effective population size than native breeds. The present effective population sizes imply that Nordic breeds could have lost from 1 to 11% of their heterozygosity over a 20-40-year period.  相似文献   

17.
Genetic variations has been analyzed using five microsatellite markers (AHT4, HTG10, ABS2, ABS23 and CA245) in three horse breeds in Egypt (Arabian, Thoroughbred and Egyptian Native). All the microsatellites typed in this study can be considered informative they produced a number of alleles ranged from eight alleles for the microsatellites ABS23, CA245 to 13 alleles for the microsatellite HTG10. The most polymorphic microsatellite was HTG10. The values of He for the five microsatellite studied were: 0.754, 0.829 and 0.807 for the breeds Arabian, Thoroughbred and Egyptian Native, respectively. The highest He value for all markers was detected in Thoroughbred breed, then The Egyptian Native and lastly in The Arabian breed. The mean values of PIC which obtained from the present study ranged from 0.686 to 0.764. Fst value may indicate the presence of gene flow between horse breeds. The values of genetic distances and phylogeny tree proved that Arabian and Native horses are coming from one ancestor while the Thoroughbred is coming from another ancestor. The values obtained for allele diversity, heterozygosity, inbreeding measurements and gene diversity showed that horse breeds understudy, moreover the present study results points to the usefulness of evaluations of diversity using molecular markers for the choice of breeds worthy of conservation.  相似文献   

18.
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 FST) 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.  相似文献   

19.
The present study reports on the incidence of X-Y aneuploidy in the sperm population of two indigenous cattle breeds reared in Italy for beef purposes, the Podolian and Maremmana. Totally, more than 50 000 sperm nuclei from 10 subjects (5 from each breed) have been fluorescent in situ hybridization (FISH) analyzed by using Xcen- and Y-chromosome-specific painting probes. In both breeds, the fraction of Y-bearing sperm was significantly higher (P < 0.01) compared with the X-counterpart. The rates of X-Y aneuploidy were 0.180% and 0.200%, respectively, in the Podolian and Maremmana. No significant interindividual differences were found. Average frequencies of disomic and diploid sperm were 0.149% and 0.031% in the former and 0.098% and 0.102% in the latter. Significant differences (P < 0.05) were found among the XX-XY and YY-disomy classes in both breeds, while diploidy classes were uniformly represented. In the Podolian breed, disomies were more frequent than diploidies (P < 0.05), whereas in the Maremmana they showed similar frequencies. In both breeds disomies arising from errors in meiosis I (X-Y disomies) were more represented than those arising in meiosis II (XX and YY), while this difference was not detected for diploidies. The present study provides specific information on the incidence of X-Y sperm aneuploidy in two indigenous breeds of cattle, in order to establish a breed-specific ‘aneuploidy data-base' that could be used as reference for genetic improvement and future monitoring of the reproductive health of the breed.  相似文献   

20.
德宏水牛微卫星标记分析的群体遗传变异   总被引:6,自引:0,他引:6  
德宏水牛是云南省地方水牛的优良品种之一,为了进一步阐明其群体遗传变异和遗传结构,筛选了分别位于水牛14条染色体上的15对微卫星引物,对德宏水牛81个个体进行了检测分析.共检测到62个等位基因,每个座位等位基因数目从2到6个不等,平均等位基因数为4.13,该水牛群体期望杂合度和多态信息含量分别为0.6520±0.1526和0.5863±0.1789,各座位的遗传分化系数在0~0.0919之间,平均值为0.0202.每个座位的基因流较大,平均12.1502.研究结果表明德宏水牛群体遗传多样性较丰富,亚群间的遗传分化程度低,基因流较大,且很少发生近交.  相似文献   

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