• 제목/요약/키워드: Polymorphism chromosome

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Genome-wide association studies to identify quantitative trait loci and positional candidate genes affecting meat quality-related traits in pigs

  • Jae-Bong Lee;Ji-Hoon Lim;Hee-Bok Park
    • Journal of Animal Science and Technology
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    • 제65권6호
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    • pp.1194-1204
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    • 2023
  • Meat quality comprises a set of key traits such as pH, meat color, water-holding capacity, tenderness and marbling. These traits are complex because they are affected by multiple genetic and environmental factors. The aim of this study was to investigate the molecular genetic basis underlying nine meat quality-related traits in a Yorkshire pig population using a genome-wide association study (GWAS) and subsequent biological pathway analysis. In total, 45,926 single nucleotide polymorphism (SNP) markers from 543 pigs were selected for the GWAS after quality control. Data were analyzed using a genome-wide efficient mixed model association (GEMMA) method. This linear mixed model-based approach identified two quantitative trait loci (QTLs) for meat color (b*) on chromosome 2 (SSC2) and one QTL for shear force on chromosome 8 (SSC8). These QTLs acted additively on the two phenotypes and explained 3.92%-4.57% of the phenotypic variance of the traits of interest. The genes encoding HAUS8 on SSC2 and an lncRNA on SSC8 were identified as positional candidate genes for these QTLs. The results of the biological pathway analysis revealed that positional candidate genes for meat color (b*) were enriched in pathways related to muscle development, muscle growth, intramuscular adipocyte differentiation, and lipid accumulation in muscle, whereas positional candidate genes for shear force were overrepresented in pathways related to cell growth, cell differentiation, and fatty acids synthesis. Further verification of these identified SNPs and genes in other independent populations could provide valuable information for understanding the variations in pork quality-related traits.

유전자 알고리즘을 이용한 하플로타입 추론 (Haplotype Inference Using a Genetic Algorithm)

  • 이시영;한현구;김희철
    • 한국정보과학회논문지:시스템및이론
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    • 제33권6호
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    • pp.316-325
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    • 2006
  • 인간과 같은 2배체의 각 염색체는 부모로부터 물려받은 2벌의 복제로 이루어져 있다. 이들 각 복제에서 SNP(single nucleotide polymorphism) 서열 정보를 하플로타입이라 부른다. 인간의 하플로타입 지도를 완전히 찾는 것은 인간 지놈의 중요한 작업 중의 하나인데, 실험적인 방법으로 하플로타입을 직접 얻는 것은 시간이 많이 걸리고 비용이 많이 든다. 따라서 두 하플로타입 정보가 혼합된 지노타입의 샘플들로부터 하플로타입을 추론하는 것에 대하여 연구되어왔다. 이 논문에서는 지노타입들을 설명하는 최소 개수의 하플로타입들을 찾는 모델(최소 하플로타입 추론문제)에 근거하여, 유전자 알고리즘을 사용하여 하플로타입을 추론하는 새로운 접근 방법을 제시한다. 좋은 결과를 주는 것으로 알려진 HAPAR[1]와 이 논문에 제시한 알고리즘을 컴퓨터 실험에 의한 비교를 통하여, 입력이 클 때 이 논문의 알고리즘이 수행시간은 적게 걸리면서 정확성이 비슷함을 보인다. 또한 이 실험 결과를 최근에 제시된 방법인 PTG[2]와 비교한다.

Effects of Single Nucleotide Polymorphism Marker Density on Haplotype Block Partition

  • Kim, Sun Ah;Yoo, Yun Joo
    • Genomics & Informatics
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    • 제14권4호
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    • pp.196-204
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    • 2016
  • Many researchers have found that one of the most important characteristics of the structure of linkage disequilibrium is that the human genome can be divided into non-overlapping block partitions in which only a small number of haplotypes are observed. The location and distribution of haplotype blocks can be seen as a population property influenced by population genetic events such as selection, mutation, recombination and population structure. In this study, we investigate the effects of the density of markers relative to the full set of all polymorphisms in the region on the results of haplotype partitioning for five popular haplotype block partition methods: three methods in Haploview (confidence interval, four gamete test, and solid spine), MIG++ implemented in PLINK 1.9 and S-MIG++. We used several experimental datasets obtained by sampling subsets of single nucleotide polymorphism (SNP) markers of chromosome 22 region in the 1000 Genomes Project data and also the HapMap phase 3 data to compare the results of haplotype block partitions by five methods. With decreasing sampling ratio down to 20% of the original SNP markers, the total number of haplotype blocks decreases and the length of haplotype blocks increases for all algorithms. When we examined the marker-independence of the haplotype block locations constructed from the datasets of different density, the results using below 50% of the entire SNP markers were very different from the results using the entire SNP markers. We conclude that the haplotype block construction results should be used and interpreted carefully depending on the selection of markers and the purpose of the study.

Bovine Genome-wide Association Study for Genetic Elements to Resist the Infection of Foot-and-mouth Disease in the Field

  • Lee, Bo-Young;Lee, Kwang-Nyeong;Lee, Taeheon;Park, Jong-Hyeon;Kim, Su-Mi;Lee, Hyang-Sim;Chung, Dong-Su;Shim, Hang-Sub;Lee, Hak-Kyo;Kim, Heebal
    • Asian-Australasian Journal of Animal Sciences
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    • 제28권2호
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    • pp.166-170
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    • 2015
  • Foot-and-mouth disease (FMD) is a highly contagious disease affecting cloven-hoofed animals and causes severe economic loss and devastating effect on international trade of animal or animal products. Since FMD outbreaks have recently occurred in some Asian countries, it is important to understand the relationship between diverse immunogenomic structures of host animals and the immunity to foot-and-mouth disease virus (FMDV). We performed genome wide association study based on high-density bovine single nucleotide polymorphism (SNP) chip for identifying FMD resistant loci in Holstein cattle. Among 624532 SNP after quality control, we found that 11 SNPs on 3 chromosomes (chr17, 22, and 15) were significantly associated with the trait at the p.adjust <0.05 after PERMORY test. Most significantly associated SNPs were located on chromosome 17, around the genes Myosin XVIIIB and Seizure related 6 homolog (mouse)-like, which were associated with lung cancer. Based on the known function of the genes nearby the significant SNPs, the FMD resistant animals might have ability to improve their innate immune response to FMDV infection.

Polymorphism Identification, RH Mapping and Association of ${\alpha}$-Lactalbumin Gene with Milk Performance Traits in Chinese Holstein

  • Zhang, Jian;Sun, Dongxiao;Womack, J.E.;Zhang, Yi;Wang, Yachun;Zhang, Yuan
    • Asian-Australasian Journal of Animal Sciences
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    • 제20권9호
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    • pp.1327-1333
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    • 2007
  • Lactose synthase catalyses the formation of lactose which is the major osmole of bovine milk and regulates the milk volume. Alpha-lactalbumin (${\alpha}$-LA) is involved in the synthesis of lactose synthase in the mammary gland. Therefore ${\alpha}$-LA is regarded as a plausible candidate gene for the milk yield trait. To determine whether ${\alpha}$-LA is associated with milk performance traits, 1,028 Chinese Holstein cows were used to detect polymorphisms in the ${\alpha}$-LA by means of single-strand conformation polymorphism (SSCP). Two nucleotide transitions were identified in the 5'flanking region and intron 3 of ${\alpha}$-LA. Associations of such polymorphisms with five milk performance traits were analyzed using a general linear model procedure. No significant associations were observed between these polymorphisms and the five milk performance traits (p>0.05). RH mapping placed ${\alpha}$-LA on BTA5q21, linked most closely to markers U63110, CC537786 and L10347 (LOD>8.3), which is far distant from the region of the quantitative trait locus (QTL) on bovine chromosome 5 for variation in the milk yield trait. In summary, based on our findings, we eliminated these SNPs from having an effect on milk performance traits.

Estimation of effective population size using single-nucleotide polymorphism (SNP) data in Jeju horse

  • Do, Kyoung-Tag;Lee, Joon-Ho;Lee, Hak-Kyo;Kim, Jun;Park, Kyung-Do
    • Journal of Animal Science and Technology
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    • 제56권8호
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    • pp.28.1-28.6
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    • 2014
  • This study was conducted to estimate the effective population size using SNPs data of 240 Jeju horses that had raced at the Jeju racing park. Of the total 61,746 genotyped autosomal SNPs, 17,320 (28.1%) SNPs (missing genotype rate of >10%, minor allele frequency of <0.05 and Hardy-Weinberg equilibrium test P-value of < $10^{-6}$) were excluded after quality control processes. SNPs on the X and Y chromosomes and genotyped individuals with missing genotype rate over 10% were also excluded, and finally, 44,426 (71.9%) SNPs were selected and used for the analysis. The measures of the LD, square of correlation coefficient ($r^2$) between SNP pairs, were calculated for each allele and the effective population size was determined based on $r^2$ measures. The polymorphism information contents (PIC) and expected heterozygosity (HE) were 0.27 and 0.34, respectively. In LD, the most rapid decline was observed over the first 1 Mb. But $r^2$ decreased more slowly with increasing distance and was constant after 2 Mb of distance and the decline was almost linear with log-transformed distance. The average $r^2$ between adjacent SNP pairs ranged from 0.20 to 0.31 in each chromosome and whole average was 0.26, while the whole average $r^2$ between all SNP pairs was 0.02. We observed an initial pattern of decreasing $N_e$ and estimated values were closer to 41 at 1 ~ 5 generations ago. The effective population size (41 heads) estimated in this study seems to be large considering Jeju horse's population size (about 2,000 heads), but it should be interpreted with caution because of the technical limitations of the methods and sample size.

Clinical, Cytogenetic and CYP1A1 exon-1 Gene Mutation Analysis of Beedi Workers in Vellore Region, Tamil Nadu

  • Sundaramoorthy, Rajiv;Srinivasan, Vasanth;Gujar, Jidnyasa;Sen, Ayantika;Sekar, Nishu;Abilash, Valsala Gopalakrishnan
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권12호
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    • pp.7555-7560
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    • 2013
  • Background: Beedi rollers are exposed to unburnt tobacco dust through cutaneous and pharyngeal route and it is extremely harmful to the body since it is carcinogenic in nature and can cause cancer during long exposure. This indicates that occupational exposure to tobacco imposes considerable genotoxicity among beedi workers. Materials and Methods: In the present study, 27 beedi workers and age and sex matched controls were enrolled for clinical, cytogenetics and molecular analysis. Clinical features were recorded. The workers were in the age group of 28-67 years and were workers exposure from 8-60 years. Blood samples were collected from workers and control subjects and lymphocyte cultures were carried out by using standard technique, slides were prepared and 50 metaphases were scored for each sample to find the chromosomal abnormalities. For molecular analysis the genomic DNA was extracted from peripheral blood, to screen the variations in gene, the exon 1 of CYP1A1 gene was amplified by polymerase chain reaction (PCR) and then screened with Single Strand Conformation Polymorphism (SSCP) analysis. Results: A statistically significant increase was observed in the frequencies of chromosomal aberrations in exposed groups when compared to the respective controls and variations observed in Exon 1 of CYP1A1(Cytochrome P450, family 1, subfamily A, polypeptide 1) gene. Conclusions: This study shows that, the toxicants present in the beedi that enter into human body causes disturbance to normal state and behavior of the chromosomes which results in reshuffling of hereditary material causing chromosomal aberrations and genomic variations.

Identification of SNPs tightly linked to the QTL for pod shattering in soybean[Glycine max (L.) Merr.]

  • Kim, Kyung-Ryun;Kim, Kyung Hye;Go, Hong Min;Lee, Ju Seok;Moon, Jung-Kyung;Ha, Bo-Keun;Jeong, Soon-Chun;Kim, Namshin;Kang, Sungtaeg
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.146-146
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    • 2017
  • The pod shattering or dehiscence is essential for the propagation of pod-bearing plant species in the wild, but it causes significant yield losses during harvest of domesticated crop plants. Identifying novel molecular makers, which are linked to seed-shattering genes, is needed to employ the molecular marker-assisted selection for efficiently developing shattering-resistant soybean varieties. In this study, a genetic linkage map was constructed using 115 recombinant inbred lines (RILs) developed from crosses between the pod shattering susceptible variety, Keunol, and resistant variety, Sinpaldal. A 180 K Axiom(R) SoyaSNPs data and pod shattering data from two environments in 2001 and 2015 were used to identify quantitative trait loci (QTL) for pod shattering. A major QTL was identified between two flanking single nucleotide polymorphism (SNP) markers, AX-90320801 and AX-90306327 on chromosome 16 with 1.3 cM interval, 857 kb of physical range. In sequence, genotype distribution analysis was conducted using extreme phenotype RILs. This could narrow down the QTL down to 153 kb on the physical map and was designated as qPDH1-KS with 6 annotated gene models. All exons within qPDH1-KS were sequenced and the 6 polymorphic SNPs affecting the amino acid sequence were identified. To develop universally available molecular markers, 38 Korean soybean cultivars were investigated by the association study using the 6 identified SNPs. Only two SNPswere strongly associated with the pod shattering. These two identified SNPs will help to identify the pod shattering responsible gene and to develop pod shattering-resistant soybean plants using marker-assisted selection.

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Predicting the Accuracy of Breeding Values Using High Density Genome Scans

  • Lee, Deuk-Hwan;Vasco, Daniel A.
    • Asian-Australasian Journal of Animal Sciences
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    • 제24권2호
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    • pp.162-172
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    • 2011
  • In this paper, simulation was used to determine accuracies of genomic breeding values for polygenic traits associated with many thousands of markers obtained from high density genome scans. The statistical approach was based upon stochastically simulating a pedigree with a specified base population and a specified set of population parameters including the effective and noneffective marker distances and generation time. For this population, marker and quantitative trait locus (QTL) genotypes were generated using either a single linkage group or multiple linkage group model. Single nucleotide polymorphism (SNP) was simulated for an entire bovine genome (except for the sex chromosome, n = 29) including linkage and recombination. Individuals drawn from the simulated population with specified marker and QTL genotypes were randomly mated to establish appropriate levels of linkage disequilibrium for ten generations. Phenotype and genomic SNP data sets were obtained from individuals starting after two generations. Genetic prediction was accomplished by statistically modeling the genomic relationship matrix and standard BLUP methods. The effect of the number of linkage groups was also investigated to determine its influence on the accuracy of breeding values for genomic selection. When using high density scan data (0.08 cM marker distance), accuracies of breeding values on juveniles were obtained of 0.60 and 0.82, for a low heritable trait (0.10) and high heritable trait (0.50), respectively, in the single linkage group model. Estimates of 0.38 and 0.60 were obtained for the same cases in the multiple linkage group models. Unexpectedly, use of BLUP regression methods across many chromosomes was found to give rise to reduced accuracy in breeding value determination. The reasons for this remain a target for further research, but the role of Mendelian sampling may play a fundamental role in producing this effect.

감염 근관에서 분리된 연쇄구균의 16S Ribosomal DNA 중합효소 연쇄반응과 제한효소 절단길이 다형성에 관한 연구 (POLYMERASE CHAIN REACTION AND RESTRICTION FRAGMENT LENGTH POLYMORPHISM OF 16S RIBOSOMAL DNA OF STREPTOCOCCI ISOLATED FROM INFECTED ROOT CANALS)

  • 정희일;임미경
    • Restorative Dentistry and Endodontics
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    • 제20권2호
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    • pp.577-609
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    • 1995
  • Bacteria have been regarded as one of the most important factors in pulpal and periapical diseases. Streptococci are frequently isolated facultative anaerobes in infected root canals. Recently molecular biological techniques have been rapidly progressed. This study was designed to apply the molecular biological tools to the identification and classification of streptococci in the endodontic microbiology. Streptococci isolated from infected root canals were identified with both Vitek Systems and API 20 STREP. Identification results were somewhat different in several strains of streptococci. Eighteen streptococci and enterococcal was difficult so to digest plasmid DNA using Hind III and EcoRI to differentiate strains by restriction enzyme analysis of plasmid DNA. 16S rDNA of chromosome was amplified by polymerase chain reaction(PCR) and then restricition fragment length polymorphism(RFLP) using several restriction enzymes was observed. The molecular mass of 16S rDNA of chromosomal DNA was approximately 1.4kb. There were three to five RFLP patterns using eight restriction enzymes. RFLP patterns digested with CfoI which recognizes four base sequences were identical in all stains. Hind III which recognizes six base sequences could not digest the 16S rDNA. Restriction enzymes which recognize five base sequences were suitable for RFLP pattern analysis. At least three different restriction enzymes were needed to compare each strains. 16S rDNA PCR-RFLP was simple and rapid to differentiate and classify strains and could be used in the epidemiological study of root canal infections.

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