首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 125 毫秒
1.
Ankamali pigs, the domesticated native pigs of Kerala province of India were genetically characterized using 23 FAO recommended microsatellite markers and were compared with other native Indian pig types and Large White pigs. Twenty‐six blood samples were collected from genetically unrelated animals from their breeding tract and DNA was isolated by standard procedure of phenol/chloroform. The genomic DNA was amplified by polymerase chain reaction (PCR) at these 23 microsatellite loci, which were also used earlier to characterize Desi (North Indian) and Gahuri (North‐East Indian) pigs, the other two native domesticated pig types of India. The PCR products were resolved by denaturing urea‐polyacrylamide gel electrophoresis and alleles were visualized after silver nitrate staining. The data were analysed for allele size range, number of alleles, allelic frequencies, heterozygosity and polymorphism information content for each locus. The allele size range varied between 92–108 bp at locus S0026 and 280–296 bp at locus IGF‐1. The total number of alleles varied between five (S0178 and S0386) and 11 (S0355). The mean observed and expected heterozygosities were found to be 0.74 ± 0.09 and 0.83 ± 0.03 respectively. In the neighbour‐joining dendrogram based on DA genetic distances developed after 1000 bootstraps, the Ankamali pigs did not show genetic closeness either with other native Indian pig types or exotic Large White pigs with high bootstrap values indicating genetic distinctness of Ankamali pigs.  相似文献   

2.
Polymorphisms for seven microsatellite loci in three red deer subspecies (9 populations) found in XinJiang were detected by polymerase chain reaction (PCR), 12% nondenaturation polyacrylamide gel electrophoresis and the Sanguinetti silver staining method. Numbers of alleles, average effective numbers of alleles (E) and the average rate of homozygosity, allelic frequencies of seven microsatellite loci, polymorphism information content (PIC), mean heterozygosity (H) and genetic distances among the populations were calculated for each population. Dendrograms were constructed based on genetic distances by the neighbor‐joining method (NJ), utilizing molecular evolutionary genetics analysis software PHYLIP (3.6). The phylogenetic tree was constructed based on allelic frequencies using maximum likelihood (ML); the bootstrap value was estimated by bootstrap test in the tree. Lastly, phylogenesis was analyzed. The results showed that four of the seven microsatellite loci were highly polymorphic, but BMS2508 and Celjp0023 showed no polymorphism and BM5004 was a neutral polymorphism. It is our conclusion that the four microsatellite loci are effective DNA markers for the analysis of genetic diversity and phylogenetic relationships among the three red deer subspecies. The mean PIC, H and E‐values across the microsatellite loci were 0.5393, 0.5736 and 2.64, which showed that these microsatellite loci are effective DNA markers for the genetic analysis of red deer. C.e. songaricus populations from Regiment 104, 151 and Hami are clustered together. C.e. yarkandensis populations from Regiment 35, Xaya and Alaer are clustered together. These two clusters also cluster together. Lastly, C.e. sibiricus populations from Burqin, Regiment 188 and the first two clusters were clustered together. The phylogenetic relationship among different red deer populations is consistent with the known origin, history of breeding and geographic distributions of populations.  相似文献   

3.
  相似文献   

4.
Chromosomes from cultured fibroblasts of two southern African ground squirrel species, Xerus inauris (2n = 38) and X. princeps (2n = 38), were compared using G-banding, C-banding and silver nitrate staining for the detection of NORs (nucleolar organizer regions). The karyoptypes of the two species, whose taxonomic status is the subject of some uncertainty, are largely identical except for a subtle heterochromatic difference which affects a single autosomal chromosome pair in X. inauris. The species specificity of this marker in their zone of contact indicates an absence of gene flow between these taxa and gives credence to the recognition of X. inauris and X. princeps as two biologically distinct species.  相似文献   

5.
Mycoplasma hyosynoviae strains from Denmark, Germany, Japan, Sweden, the Netherlands and the UK were examined for variations in the genomic DNA and within the 16S ribosomal RNA (rRNA) gene. Variations in the chromosomal DNA among 57 isolates recovered from the respiratory tract and joints of pigs, were investigated by analysis of amplified fragment length polymorphisms of the BglII and MfeI restriction sites and by pulsed‐field gel electrophoresis of a BssHII digest of chromosomal DNA. Both methods allowed unambiguous differentiation of the analysed strains and showed similar discriminatory potential for the differentiation of M. hyosynoviae isolates. Concordant results obtained with the two whole‐genome fingerprinting techniques evidence the considerable intraspecies genetic heterogeneity of M. hyosynoviae. Sixteen field strains of M. hyosynoviae and the type strain S16T were further examined for variation within the 16S rRNA gene. Ten field strains possessed the 16S rDNA sequences identical to the type strain, while the remaining six strains had sequences that differed by one to two nucleotides from that obtained from the type strain.  相似文献   

6.
The uncoupling protein 1 (UCP1) plays an important role in the regulation of lipolysis and thermogenesis in adipose tissues. Genetic variation within three regions (the promoter, intron 2 and exon 5) of the ovine UCP1 gene (UCP1) was investigated using polymerase chain reaction‐single‐strand conformational polymorphism (PCR‐SSCP) analyses. These revealed three promoter variants (designated A, B and C) and two intron 2 variants (a and b). The association of this genetic variation with variation in lamb carcass traits and postweaning growth was investigated in New Zealand (NZ) Romney and Suffolk sheep. The presence of B in a lamb's genotype was associated with decreased subcutaneous carcass fat depth (V‐GR) (p = 0.004) and proportion of total lean meat yield of loin meat (p = 0.005), and an increased proportion of total lean meat yield of hind‐leg meat (p = 0.018). In contrast, having two copies of C was associated with increased V‐GR (p < 0.001) and proportion of total lean meat yield of shoulder meat (p = 0.009), and a decreased hind‐leg yield (p = 0.032). No associations were found with postweaning growth. These results suggest that ovine UCP1 is a potential gene marker for carcass traits.  相似文献   

7.
We investigated whether regular changes of the sire in a breeding farm of Hokkaido Native Horses (HKDs) enables the DNA‐level genetic variation of the produced animals to be maintained. The genotypes of 31 microsatellite markers were identified and analyzed in 207 animals produced in a breeding farm in which the sire was replaced every 3 to 5 years. The mean allele number indicating the degree of genetic variation was 5.97 and was similar to those reported previously. The mean observed heterozygosity was 0.74 and was higher than the expected heterozygosity, 0.69; FIS was ?0.07, indicating that the analyzed animals reflected frequent outbreeding and had maintained genetic variation. Based on genetic structural analysis, the number of genetic subpopulations of the animals was estimated to be as 6, and the majority (more than 50%) of each subpopulation corresponded to the progeny of one of the sires used in the breeding farm; these observations suggested that genetic variation in the analyzed animals reflected the genetic differences among sires. Pedigree records indicated that the average co‐ancestry coefficient between sires used in the breeding farm was 0.015 corresponding to second cousin. This level of kinship among sires is acceptable for producing HKDs that maintain genetic variation.  相似文献   

8.
Gonadotropin releasing hormone and its receptor (GNRHR) play a critical role in sexual differentiation and reproduction. Available evidence shows a strong genetic component in the timing of puberty. In bovines, there are significant differences within and among beef breeds in the time when bulls reach puberty. Despite its economic importance, there are not many SNPs or genetic markers associated with this characteristic. The aims of the study were to identify DNA polymorphism in the bovine GNRHR by re-sequencing analysis, determine haplotype phases, and perform a population study in a selected tag SNP in six breeds. Eight SNPs were detected, including: one in the Upstream Regulatory Region (URR), five in the coding regions, and two in non-coding regions. This polymorphism level corresponds to one variant every 249.4 bp and a global nucleotide diversity of 0.385. Two haplogroups comprising nine haplotypes and two linkage blocks were detected. Despite 5 tag SNPs were required to capture all variability, just one SNP allowed to define both haplogroups, and only two SNPs were needed to differentiate the most common haplotypes. An additional taq SNP was necessary to identify both URR variants. Allele-frequency analysis of a selected taq SNP among breeds showed a geographical cline. European Bos taurus breeds had lower frequencies of the C allele than B. indicus type cattle, while Creole cattle and Wagyu breeds had intermediate frequency. There was a significant correlation between frequency profile and timing of puberty among the studied breeds, which seems to suggest that genetic variation within bovine GNRHR gene could explain at least part of the reported variability.  相似文献   

9.
Osteochondrosis (OC) is an injury to cartilage canals with a following necrosis in the growth cartilage, from there it can develop to osteochondrosis dissecans (OCD). Due to its high impact in the equine industry, new insights into predisposing factors and potential high‐risk genetic variants are warranted. This article reviews advancements in quantitative and molecular genetics in refining estimation of genetic parameters and identifying predisposing genetic loci. Heritabilities were highest for hock OC with estimates at 0.29–0.46 in Hanoverian warmblood and Norwegian trotters, whereas in Thoroughbreds only very low genetic variation seemed to be present in hock OC lesions. Whole genome scans using the Illumina Equine SNP50 or SNP70 Beadchip were performed in Thoroughbred, Standardbred, French and Norwegian trotter, Hanoverian and Dutch warmblood. Validation studies in Spanish Purebred and Hanoverian warmblood horses corroborated OC risk loci on ECA 3, 14, 27 and 29. Particularly, a strong association with hock‐OCD was found for a single nucleotide polymorphism (SNP) on horse chromosome (ECA) 3 upstream to the LCORL gene. Gene expression and microRNA analyses may be helpful to understand pathophysiological processes in equine OC and to connect OCD‐associated genomic regions with potential candidate genes. Furthermore progress in elucidating the underlying genetic variants and pathophysiological changes in OC may be expected from whole genome DNA and RNA next‐generation sequencing studies.  相似文献   

10.
The study characterized genetic diversity and genetic structure of five indigenous pig populations (Ha Lang, Muong Te, Mong Cai, Lung and Lung Pu), two wild pig populations (Vietnamese and Thai wild pigs) and an exotic pig breed (Yorkshire) using FAO/ISAG recommended 16 microsatellite markers in 236 samples. All estimated loci were very polymorphic indicated by high values of polymorphism information content (from 0.76 in S0225 to 0.92 in Sw2410). Indigenous populations had very high level of genetic diversity (mean He = 0.75); of all indigenous breeds, Lung Pu showed highest mean number of alleles (MNA = 10.1), gene diversity (He = 0.82), allele richness (5.33) and number of private alleles (10). Thirteen percentage of the total genetic variation observed was due to differences among populations. The neighbour‐joining dendrogram obtained from Nei's standard genetic distance differentiated eight populations into four groups including Yorkshire, two wild populations, Mong Cai population and a group of four other indigenous populations. The Bayesian clustering with the admixture model implemented in Structure 2.1 indicated seven possible homogenous clusters among eight populations. From 79% (Ha Lang) to 98% (Mong Cai). individuals in indigenous pigs were assigned to their own populations. The results confirmed high level of genetic diversity and shed a new light on genetic structure of Vietnam indigenous pig populations.  相似文献   

11.
We have collected more than 190 000 porcine expressed sequence tags (ESTs) from full‐length complementary DNA (cDNA) libraries and identified more than 2800 single nucleotide polymorphisms (SNPs). In this study, we tentatively chose 222 SNPs observed in assembled ESTs to study pigs of different breeds; 104 were selected by comparing the cDNA sequences of a Meishan pig and samples of three‐way cross pigs (Landrace, Large White, and Duroc: LWD), and 118 were selected from LWD samples. To evaluate the genetic variation between the chosen SNPs from pig breeds, we determined the genotypes for 192 pig samples (11 pig groups) from our DNA reference panel with matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry. Of the 222 reference SNPs, 186 were successfully genotyped. A neighbor‐joining tree showed that the pig groups were classified into two large clusters, namely, Euro‐American and East Asian pig populations. F‐statistics and the analysis of molecular variance of Euro‐American pig groups revealed that approximately 25% of the genetic variations occurred because of intergroup differences. As the FIS values were less than the FST values, the clustering, based on the Bayesian inference, implied that there was strong genetic differentiation among pig groups and less divergence within the groups in our samples.  相似文献   

12.
Thirty‐one Salmonella Enteritidis strains isolated from chickens, broilers and hens were analysed by genotypic typing including REP‐PCR, ERIC‐PCR and ITS profiling (PCR‐ribotyping). Analysis of DNA banding patterns generated by REP‐PCR revealed the presence of 22 different genotypes, which were grouped by dendrogram analysis into three distinct lineages (maximum similarity approx. 50%). Each isolate of S. Enteritidis analysed by ERIC‐PCR generated an individual DNA pattern. Again, these isolates could be divided into three distinct genomic groups (maximum similarity approx. 60%) by their ERIC‐PCR fingerprints. REP‐ and ERIC‐PCR were found to be more discriminatory for typing of S. Enteritidis than ITS profiling. Amplification of the 16S‐23S rDNA spacer region gave nine different profiles of DNA, subdivided into two closely related groups by dendrogram analysis. In summary, data obtained by genotyping methods for S. Enteritidis isolates from regions located in the south‐west and the central parts of Poland revealed an enormous heterogeneity among analysed samples, and proved that REP‐ and ERIC‐PCR are highly discriminatory techniques, which can be used, in addition to conventional methods, in epidemiological studies of S. Enteritidis infections.  相似文献   

13.
2′, 5′‐Oligoadenylate synthetases (OAS) are important components of an interferon‐mediated antiviral pathway. No polymorphisms in exonic regions of bovine OAS1 gene have been identified and associated with reproduction traits. The objective of the study was to detect and evaluate the effects of mutations in exonic region of bovine OAS1 gene with reproduction traits in cattle. DNA samples collected from 250 individual cows of two Indian dairy breeds (Sahiwal and Frieswal) of cattle were used in the study. The genetic variants of the OAS1 gene were identified with polymerase chain reaction–single‐strand conformation polymorphism (PCR‐SSCP) and sequence analysis using seven set of primer pairs. The PCR‐SSCP analysis revealed polymorphism in the fragments comprising of exon 2, exon 5 and first fragment of exon 6 while the fragments of exons 1, 3, 4 and second fragment of exon 6 were monomorphic in Sahiwal and Frieswal cattle. The mutations in the amplified region comprising of exon 2 were found to have significant association with age at first breeding and calving, service period, dry period and pregnancy rate. Significant associations were found between SNPs in the exon 5 and service and dry periods of the animal, whereas the genetic variants in the first fragment of the exon 6 showed significant association with age at first breeding and calving. To our knowledge, this study demonstrated for the first time that the polymorphisms in OAS1 gene were associated with reproductive traits and it can be chosen as a candidate gene for improvement of reproductive performance of cattle.  相似文献   

14.
The main objective of this study was to investigate the polymorphism of GDF9 and BMPR1B genes and their relationship with litter size in Markhoz goats. The polymorphism of GDF9 and BMPR1B genes as well‐documented genes regarding fecundity in sheep and goat was investigated using RFLP‐PCR and a tetra‐primer amplification refractory mutation system‐PCR (T‐ARMS‐PCR) in Markhoz goats. The 164 blood samples were collected from the raised goats in Sanandaj Markhoz goat Performance Testing Station. The DNA extraction was carried out by salting‐out procedure, and then, PCR was performed using four and two pairs of primers to detect polymorphism in GDF9 and BMPR1B genes, respectively. To disclose GDF9 loci polymorphism, PCR products were digested with SspI (G3288A), PvuII (G423A), MvaI (A959C) and MspI (G1189A) restriction enzymes. The results showed that these mutations are available in tested animals. Parity had no significant effect on litter size. Also, the effects of different genotypes of GDF9 and BMPR1B had no significant effect on litter size. Further studies with a high number of animals with minimum relatedness for testing the association of these SNPs and others in the fecundity genes with reproductive traits may be worthwhile.  相似文献   

15.
A molecular technique based on the restriction fragment length polymorphism of the 16S ribosomal genes amplified by a polymerase chain reaction (PCR), referred to as amplified 16S ribosomal DNA restriction analysis (ARDRA), was designed to identify 19 Avibacterium paragallinarum strains isolated from infraorbital sinus and nasal turbinate bone samples of broiler chickens, breeders, and laying hens from different regions of Peru. The 16S rDNA was amplified by PCR using a pair of bacterial universal primers and restriction analysis of 16S rDNA sequences was done to select endonucleases with the highest number of cutting points inside the 16S rDNA. The DNA patterns with DdeI and RsaI endonucleases were identical for the 19 A. paragallinarum strains, but differed from those obtained for Ornithobacterium rhinotracheale, a bacterium with a high genetic and phenotypic resemblance to A. paragallinarum, as well as from Escherichia coli, a bacterium associated with infectious coryza. The ARDRA method could prove to be valuable for molecular identification of A. paragallinarum, a microorganism implicated in respiratory diseases in commercial birds.  相似文献   

16.
Twenty strains of lactic acid bacteria were isolated from six traditional Tibetan Qula cheese made from yak which were collected from northwest China, including Tibet, Qinghai and Gansu province. These isolates were subjected to phenotypic and genetic analyses. All isolates were Gram‐positive and catalase‐negative cocci that produced gas from glucose and formed D(–) isomer of lactate. Most isolates were able to grow in de Man, Rogosa and Sharpe (MRS) broth at pH values 3.0–9.0 and in 6.5% NaCl (w/v). According to analytical profile index 50 carbohydrates (API 50 CH) fermentation patterns of amygdalin and arabinose, these isolates were divided into three groups (A to C). On the basis of the phylogenetic trees of 16S ribosomal DNA (rDNA) sequence, the strains in all groups were placed in the cluster making up the genus Leuconostoc, which showed that all strains should belong to Leuconostoc species. Strains in Group A and Group B exhibited similarity of 16S rDNA sequence of over 99% to Leuconostoc mesenteroides, indicating that they each comprised a single species. Strains in group C were assigned to the Leuconostoc pseudomesenteroides and their 16S rDNA sequence showed a similarity of over 99%. This study demonstrated that Leuconostoc was the dominant member among lactic acid bacteria in Qula cheese.  相似文献   

17.
Rhodococcus equi pneumonia is a major cause of morbidity and mortality in neonatal foals. Much effort has been made to identify preventative measures and new treatments for R. equi with limited success. With a growing focus in the medical community on understanding the genetic basis of disease susceptibility, investigators have begun to evaluate the interaction of the genetics of the foal with R. equi. This review describes past efforts to understand the genetic basis underlying R. equi susceptibility and tolerance. It also highlights the genetic technology available to study horses and describes the use of this technology in investigating R. equi. This review provides readers with a foundational understanding of candidate gene approaches, single nucleotide polymorphism‐based, and copy number variant‐based genome‐wide association studies, and next generation sequencing (both DNA and RNA).  相似文献   

18.
Background – The historical classification of Demodex mites has been based on their hosts and morphological features. Genome sequencing has proved to be a very effective taxonomic tool in phylogenetic studies and has been applied in the classification of Demodex. Mitochondrial 16S rDNA has been demonstrated to be an especially useful marker to establish phylogenetic relationships. Hypothesis/Objectives – To amplify and sequence a segment of the mitochondrial 16S rDNA from Demodex canis and Demodex injai, as well as from the short‐bodied mite called, unofficially, D. cornei and to determine their genetic proximity. Methods – Demodex mites were examined microscopically and classified as Demodex folliculorum (one sample), D. canis (four samples), D. injai (two samples) or the short‐bodied species D. cornei (three samples). DNA was extracted, and a 338 bp fragment of the 16S rDNA was amplified and sequenced. Results – The sequences of the four D. canis mites were identical and shared 99.6 and 97.3% identity with two D. canis sequences available at GenBank. The sequences of the D. cornei isolates were identical and showed 97.8, 98.2 and 99.6% identity with the D. canis isolates. The sequences of the two D. injai isolates were also identical and showed 76.6% identity with the D. canis sequence. Conclusion – Demodex canis and D. injai are two different species, with a genetic distance of 23.3%. It would seem that the short‐bodied Demodex mite D. cornei is a morphological variant of D. canis.  相似文献   

19.
KRT2.13 is a type II keratin wool intermediate filament (IF) protein. Extensive variation was revealed in the 5′ untranslated region (UTR) of the ovine KRT2.13 gene (KRT2.13) using polymerase chain reaction – single strand conformational polymorphism (PCR‐SSCP) analysis. Nine unique PCR‐SSCP patterns were obtained with individual sheep having either one (homozygous), or a combination of two (heterozygous) of these patterns. Seven of the amplicons that produced the apparently homozygous patterns were successfully sequenced (GenBank FJ217670 – FJ217676), revealing eight single nucleotide insertions, 10 single nucleotide substitutions, a nucleotide deletion and a 16 nucleotide insertion that occurred in only one of the sequences. The seven sequences showed between 85% and 95% homology to the previously identified KRT2.13 sequence (GenBank X72379). This study emphasizes the power of PCR‐SSCP analysis in genotyping, as this extensive variation was found in only 100 sheep, of a variety of breeds. Since variation in the 5′UTR of genes may affect their expression, this genetic variation needs to be further studied to establish its role if any, in influencing gene expression and consequently wool traits.  相似文献   

20.
The genetic variation at four milk protein loci αs1‐casein (CSN1S1), β‐casein (CSN2), κ‐casein (CSN3) and β‐lactoglobulin (LGB) was investigated in 358 animals belonging to seven populations well adapted to hot climatic conditions, reared in Africa and Italy. Bos taurus (Somba, Lagune and Modicana), Bos indicus (Sudanese Zebu Peul, Azaouak and Adamawa), and B. taurus × B. indicus (Borgou) were studied by adapting different molecular methodologies to evaluate their genetic variability. All loci were polymorphic and a new CSN2 synonymous variant, named A2′, was detected and characterized. Noteworthy differences in the distribution of alleles and haplotypes were observed between zebuine and taurine cattle showing that milk protein polymorphism is suited for discriminating B. taurus from B. indicus efficiently, and also taurine breeds. Milk protein loci, being positively selected loci, can also provide information about the occurrence of germplasm particularly useful for breeding strategies and production improvement.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号