• Title/Summary/Keyword: Population genetics

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Determination of HLA-A*02 Alleles Using Nested PCR-SSP in Korean Population

  • Lee, Kyung-Ok;Heo, Jeong-Ho-Ho;Kim, Hye-Jin;Lee, Eun-Mi;Hong, Sung-Hoi;Kim, Yoon-Jung
    • Animal cells and systems
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    • v.1 no.1
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    • pp.129-134
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    • 1997
  • HLA-A2 is one of the most diversified HLA-class I antigen with 17 subtypes so far identified at the molecular level. HLA-A*02 subtyping has significant implications on the tissue typing for organ and bone marrow transplantations. Recently, DNA-based typing methods have been successfully applied to the elucidation of HLA gene polymorphisms. In the present study, HLA-A*O2 genotyping was established by using nested polymerase chain reaction-sequence specific primers (PCR-SSP) and distribution of A*O2 alleles were determined in Korean individuals. Genomic DNA prepared from four B-lymphoblastoid cell lines and lymphocytes from serologically defined 48 HLA-A2 Korean individuals by phenol/chloroform extractions was typed. The results of the four B-lymphoblastoid cells were consistent with the previous data typed by PCR analysis. Five A*O2 alleles-A*0201, A*0203, A*0206, A*0207 and A*0210-were commonly observed in a total of 17 A*02 alleles. Of these, A*0207 (f=49.0%) was the most frequent allele in Korean population. A*0206 (f=28.3%) and A*0201 (f=17.0%) were also found frequently while A*0203 and A*0210 types were observed in less than 5%. In conclusion, the high level of discrimination for HLA-A*O2 alleles will prove useful and informative in the study of transplant survival, and may identify the importance of allelic differences not readily detectable by serology on host and donor compatibility.

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Association of UDP-galactose-4-epimerase with milk protein concentration in the Chinese Holstein population

  • Li, Cong;Cai, Wentao;Liu, Shuli;Zhou, Chenghao;Cao, Mingyue;Yin, Hongwei;Sun, Dongxiao;Zhang, Shengli;Loor, Juan J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.11
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    • pp.1725-1731
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    • 2020
  • Objective: An initial RNA-Sequencing study revealed that UDP-galactose-4-epimerase (GALE) was one of the most promising candidates for milk protein concentration in Chinese Holstein cattle. This enzyme catalyzes the interconversion of UDP-galactose and UDP-glucose, an important step in galactose catabolism. To further validate the genetic effect of GALE on milk protein traits, genetic variations were identified, and genotypes-phenotypes associations were performed. Methods: The entire coding region and the 5'-regulatory region (5'-UTR) of GALE were re-sequenced using pooled DNA of 17 unrelated sires. Association studies for five milk production traits were performed using a mixed linear animal model with a population encompassing 1,027 Chinese Holstein cows. Results: A total of three variants in GALE were identified, including two novel variants (g.2114 A>G and g.2037 G>A) in the 5'-UTR and one previously reported variant (g.3836 G>C) in an intron. All three single nucleotide polymorphisms (SNPs) were associated with milk yield (p<0.0001), fat yield (p = 0.0006 to <0.0001), protein yield (p = 0.0232 to <0.0001) and protein percentage (p<0.0001), while no significant associations were detected between the SNPs and fat percentage. A strong linkage disequilibrium (D' = 0.96 to 1.00) was observed among all three SNPs, and a 5 Kb haplotype block involving three main haplotypes with GAG, AGC, and AGG was formed. The results of haplotype association analyses were consistent with the results of single locus association analysis (p<0.0001). The phenotypic variance ratio above 3.00% was observed for milk protein yield that was explained by SNP-g.3836G >C. Conclusion: Overall, our findings provided new insights into the polymorphic variations in bovine GALE gene and their associations with milk protein concentration. The data indicate their potential uses for marker-assisted breeding or genetic selection schemes.

Genetic Variability of Farmed Olive Flounder (Paralichthys olivaceus) Populations Managed with no Consideration of Genetic Diversity (유전적 다양성이 고려되지 않은 어미 관리에 의한 양식 넙치(Paralichthys olivaceus)의 유전적 다양성의 변화)

  • Noh, Jae Koo;Kim, Hyun Chul;Park, Choul Ji;Lee, Jeong-Ho;Kim, Jong-Hyun;Lee, Mi-Sug;Kim, Woo-Jin;Kim, Kyung-Kil;Myeong, Jeong-In
    • Korean Journal of Ichthyology
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    • v.20 no.4
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    • pp.248-254
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    • 2008
  • Olive flounder (Paralichthys olivaceus) is one of the most popular farmed fish in Korea. Genetic variability of the fish was investigated by means of microsatellite DNA markers. All of the 8 microsatellite loci were analyzed in this study. For the confirmation of genetic variation during a shift in generation, microsatellite variability was compared within the same hatchery strains but produced in different spawning years. When genetic variability of farmed flounders produced in 2006 and 2007 was compared with that of 2003, a marked reduction of genetic variability was observed in the 2006 and 2007 populations. Mean number of alleles per locus and expected mean heterozygosity decreased from 9.75 and 0.796 (in 2003 population) to 7.78 and 0.785 (in 2006 population), respectively. Moreover, we have observed the distortion of allele frequency. These results show that reduced genetic variability of farmed olive flounder in processed generation has lower numbers of alleles and genetic variability than these of wild fish. Our results suggest that to have a sustainable aquaculture of this species, there is need for scientific broodstock management based on genetic variation and more intensive breeding practices to improve genetic diversity and to avoid detrimental inbreeding effects.

Luzhong mutton sheep: inbreeding and selection signatures

  • Tao, Lin;He, Xiaoyun;Wang, Fengyan;Zhong, Yingjie;Pan, Linxiang;Wang, Xiangyu;Gan, Shangquan;Di, Ran;Chu, Mingxing
    • Journal of Animal Science and Technology
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    • v.62 no.6
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    • pp.777-789
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    • 2020
  • Intense artificial selection has been imposed to Luzhong mutton sheep population in the past years. Improvements on growth and reproductive performance are two breeding goals in the present herd. Although some progresses were phenotypically observed possibly due to inbreeding induced by strong selection in terms of these traits, the genomic evaluation was poorly understood. Therefore, a high-density SNP array was used to characterize the pattern of runs of homozygosity (ROH), estimate inbreeding and inbreeding depressions on early growth performance and litter size based upon ROH, and scan positive selection signatures of recent population. Consequently, a low inbreeding level was observed which had negative effects on litter size, but not on early growth performance. And 160 genes were under selection, of which some were reported to be linked to several traits of sheep including body weight, litter size, carcass and meat quality, milk yield and composition, fiber quality and health, and the top genes were associated with growth (growth hormone [GH]- growth hormone receptor [GHR]- Insulin-like growth factor 1 [IGF1] axis) and litter size (bone morphogenic proteins [BMPs]-associated). The effectiveness of previous breeding measures was highlighted, but purging selection was proposed to alleviate the inbreeding depression on litter size, providing some genomic insights to breeding management of Luzhong mutton sheep.

Preventing Premature Convergence in Genetic Algorithms with Adaptive Population Size (유전자 집단의 크기 조절을 통한 Genetic Algorithm의 조기 포화 방지)

  • 박래정;박철훈
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.32B no.12
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    • pp.1680-1686
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    • 1995
  • GAs, effective stochastic search algorithms based on the model of natural evolution and genetics, have been successfully applied to various optimization problems. When population size is not large, GAs often suffer from the phenomenon of premature convergence in which all chromosomes in the population lose the diversity of genes before they find the optimal solution. In this paper, we propose that a new heuristic that maintains the diversity of genes by adding some chromosomes with random mutation and selective mutation into population during evolution. And population size changes dynamically with supplement of new chromosomes. Experimental results for several test functions show that when population size is rather small and the length of chromosome is not long, this method is effective.

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Genetic Distances of Scallop (Chlamys farreri) Populations investigated by PCR Procedure

  • Yoon, Jong-Man
    • Development and Reproduction
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    • v.21 no.4
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    • pp.435-440
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    • 2017
  • The author performed PCR-based genetic platform to measure the hierarchical dendrogram of Euclidean genetic distances of Korean scallop populations (KSP), particularly for Chlamys farreri, which was further compared with those of the Chinese scallop populations (CSP), by employing the with specifically designed oligonucleotide primer sets. The scallop is economically and ecologically very important bivalves in South Korea. Relatively, individuals of KSP population were fairly distantly related to that of CSP population, as shown in the hierarchical dendrogram of Euclidean genetic distances. Comparatively, individuals of KSP population were fairly distantly related to that of CSP population. Thus analysis of genetic difference between scallop populations could provide important statistics for fishery and aquaculture. Overall the results showed specific and/or conserved genetic loci between scallop populations. Information on the genetic distance of the bivalve would be helpful to understand scallop expansion or conservation in the coastal regions of South Korea. Specific markers developed by the author will be useful for the analysis of scallop population genetics and distribution in coastal region.

Isoelectric Focusing of the Hemolymph Proteins of the Silkworm, Bombyx mori

  • Staykova, Teodora;Popov, Petar;Grekov, Dimitar;Terzieva, Petia
    • International Journal of Industrial Entomology and Biomaterials
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    • v.8 no.1
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    • pp.117-121
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    • 2004
  • Soluble proteins of silkworm hemolymph were investigated by means of isoelectric focusing (IEF). The protein spectra during ontogenesis of races and inter-races hybrids kept in Bulgaria was studied. A total of 51 protein bands in the hemolymph from fourth larval instar to imago were ascertained. Stage specific expression was established. The specific expression of some protein bands in the individual spectra manifest phenotype of gene determinate polymorphism (HP F, HP J, HP K, HP L, HP Q - in the zone with pH gradient 3.5-6.2 and HP K, HP L, HP N, HP P, HP T - in the zone with pH gradient 9.5 - 6.2). Breed specific expression was observed. On the basis of the obtained results, it was established that the investigated breeds are heterogeneous and the isoelectric focusing method is successful when specifying the inner-race and inter-race polymorphism in silkworm.

Genetic diversity and population structure of indigenous chicken of Bangladesh using microsatellite markers

  • Rashid, Muhammad Abdur;Manjula, Prabuddha;Faruque, Shakila;Bhuiyan, A.K. Fazlul Haque;Seo, Dongwon;Alam, Jahangir;Lee, Jun Heon;Bhuiyan, Mohammad Shamsul Alam
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.11
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    • pp.1732-1740
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    • 2020
  • Objective: The objectives of this study were to investigate the genetic diversity, population structure and relatedness among the five chicken populations of Bangladesh using microsatellite markers. Methods: A total of 161 individuals representing 5 chicken populations (non-descript Deshi [ND], naked neck [NN], hilly [HI], Aseel [AS], and red jungle fowl [JF]) were included in this study to investigate genetic diversity measures, population structure, genetic distance and phylogenetic relationships. Genotyping was performed using 16 selected polymorphic microsatellite markers distributed across 10 chromosomes. Results: The average observed and expected heterozygosity, mean number of alleles and polymorphic information content were found to be 0.67±0.01, 0.70±0.01, 10.7 and 0.748, respectively in the studied populations. The estimated overall fixation index across the loci (F), heterozygote deficiency within (FIS) and among (FIT) chicken populations were 0.04±0.02, 0.05 and 0.16, respectively. Analysis of molecular variance analysis revealed 88.07% of the total genetic diversity was accounted for within population variation and the rest 11.93% was incurred with population differentiation (FST). The highest pairwise genetic distance (0.154) was found between ND and AS while the lowest distance was between JF and AS (0.084). Structure analysis depicted that the studied samples can be categorized into four distinct types or varieties (ΔK = 3.74) such as ND, NN, and HI where AS and JF clustered together as an admixed population. The Neighbor-Joining phylogenetic tree and discriminant analysis of principal component also showed close relatedness among three chicken varieties namely AS, HI, and JF. Conclusion: The results reflected that indigenous chicken of Bangladesh still possess rich genetic diversity but weak differentiation among the studied populations. This finding provides some important insight on genetic diversity measures that could support the designing and implementing of future breeding plans for indigenous chickens of Bangladesh.

Association Analyses with Carcass Traits in the Porcine KIAA1717 and HUMMLC2B Genes

  • Xu, D.Q.;Xiong, Y.Z.;Liu, M.;Lan, J.;Ling, X.F.;Deng, C.Y.;Jiang, S.W.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.11
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    • pp.1519-1523
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    • 2005
  • By screening a subtracted cDNA library constructed with mRNA obtained from the longissimus dorsi muscles of F1 hybrids Landrace${\times}$Yorkshire and their Yorkshire female parents, we isolated two partial sequences coding for the H3-K4-specific methyltransferase (KIAA1717) and skeletal muscle myosin regulatory light chain (HUMMLC2B) genes. In the present work we investigated two SNPs, one (C1354T) at the 3' untranslated region (UTR) of KIAA1717 and one (A345G) at the SINE (PRE-1) element of HUMMLC2B, in a resource population derived from crossing Chinese Meishan and Large White pig. The selected pigs were genotyped by means of a PCR-RFLP protocol. Significant associations were observed for the KIAA1717 C1354T polymorphic site with thorax-waist backfat thickness (p<0.05), buttock backfat thickness (p<0.05), average backfat thickness (p<0.05), loin eye height (p<0.05), loin eye area (p<0.05), carcass length to 1$^{st}$ spondyle (p<0.01) and carcass length to 1st rib (p<0.01). HUMMLC2B A345G were significantly associated with loin eye width (p<0.05), loin eye area (p<0.05). Further studies are needed to confirm these preliminary results.

Growth of Pacific abalone, Haliotis discus hannai, using selection breeding techniques (선발육종기술을 이용한 북방전복의 성장)

  • Park, Choul-Ji;Lee, Jeong-Ho;Noh, Jae Koo;Kim, Hyun Chul;Park, Jong Won;Hwang, In Jun;Kim, Sung Yeon
    • The Korean Journal of Malacology
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    • v.28 no.4
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    • pp.343-347
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    • 2012
  • The growth rates of offspring of selected abalone (SA), Haliotis discus hannai, population for rapid growth were compared to those of offsping of the control abalone (CA) at bred under the same condition. The growth traits (shell length, shell breadth and total weight) of SA were significantly faster than those of CA at this experiment. At the 45th day and 90th day, the growth rates in shell length of SA were estimated 31.7% and 17.8% faster than those of CA, total weight of SA were estimated 43.7% and 25.6%, respectively. Moreover, the relative growth rate between shell length and total weight of SA showed significant differences higher than one in CA at 90th day. The results suggest a possibility of improving the growth rate of cultured abalone using selection techniques.