• Title/Summary/Keyword: Genetic linkage

Search Result 350, Processing Time 0.031 seconds

Genetic Analysis of Flower Color Traits in Calanthe discolor, C. sieboldii, and Variants Using Molecular Linkage Map (연관지도를 이용한 새우난초, 금새우난초, 변이종의 화색의 유전분석)

  • Cho, Dong-Hoon;Chung, Mi-Young;Jee, Sun-Ok;Kim, Chang-Kil;Chung, Jae-Dong;Kim, Kyung-Min
    • Journal of Life Science
    • /
    • v.19 no.9
    • /
    • pp.1239-1244
    • /
    • 2009
  • This study was conducted to clarify the genetic relationship between Calanthe discolor, C. sieboldii and variants, and the cause of flower color variations by using a molecular linkage map and a quantitative trait loci (QTL) analysis for flower and lip color in Calanthe species native to Korea. Twenty plants were included in three C. discolor and three C. sieboldii, and fourteen variants were obtained from their habitat, Jeju-do in Korea. The flowers of C. discolor were brownish red, the values of Commission Internationale de I'Eclairage (CIE) Lab were between 40 and 50. The flowers of C. sieboldii were yellowish, the values of CIE Lab were between 110 and 130. The variants had various mixed colors that were thought to have originated from natural hybridization between C. discolor and C. sieboldii, and the values of CIE Lab were between 50 and 70. The colors of the lips were usually divided into white and yellow. C. discolor had a white lip, C. sieboldii had a yellow one, and the variants had a white to yellow one. The CIE Lab value of each color was 90 in white and 110 to 120 in yellow lips. A molecular linkage mapping was constructed based on the segregation of 154 RAPD markers using a MAPL program. Sixteen linkage groups containing 66 markers were established. It covered a total map distance of 220.4 cM. The distance between adjacent markers ranged from 0 to 6.6 cM, with an average distance of 3.3 cM. These markers are thought to be closely associated with flower and lip color expression. Among the 16 molecular linkage groups, 3 QTLs had flower color trait loci and 1 QTL had lip color trait loci.

Genetic diversity and divergence among Korean cattle breeds assessed using a BovineHD single-nucleotide polymorphism chip

  • Kim, Seungchang;Cheong, Hyun Sub;Shin, Hyoung Doo;Lee, Sung-Soo;Roh, Hee-Jong;Jeon, Da-Yeon;Cho, Chang-Yeon
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.31 no.11
    • /
    • pp.1691-1699
    • /
    • 2018
  • Objective: In Korea, there are three main cattle breeds, which are distinguished by coat color: Brown Hanwoo (BH), Brindle Hanwoo (BRH), and Jeju Black (JB). In this study, we sought to compare the genetic diversity and divergence among there Korean cattle breeds using a BovineHD chip genotyping array. Methods: Sample data were collected from 168 cattle in three populations of BH (48 cattle), BRH (96 cattle), and JB (24 cattle). The single-nucleotide polymorphism (SNP) genotyping was performed using the Illumina BovineHD SNP 777K Bead chip. Results: Heterozygosity, used as a measure of within-breed genetic diversity, was higher in BH (0.293) and BRH (0.296) than in JB (0.266). Linkage disequilibrium decay was more rapid in BH and BRH than in JB, reaching an average $r^2$ value of 0.2 before 26 kb in BH and BRH, whereas the corresponding value was reached before 32 kb in JB. Intra-population, interpopulation, and Fst analyses were used to identify candidate signatures of positive selection in the genome of a domestic Korean cattle population and 48, 11, and 11 loci were detected in the genomic region of the BRH breed, respectively. A Neighbor-Joining phylogenetic tree showed two main groups: a group comprising BH and BRH on one side and a group containing JB on the other. The runs of homozygosity analysis between Korean breeds indicated that the BRH and JB breeds have high inbreeding within breeds compared with BH. An analysis of differentiation based on a high-density SNP chip showed differences between Korean cattle breeds and the closeness of breeds corresponding to the geographic regions where they are evolving. Conclusion: Our results indicate that although the Korean cattle breeds have common features, they also show reliable breed diversity.

Advances towards Controlling Meiotic Recombination for Plant Breeding

  • Choi, Kyuha
    • Molecules and Cells
    • /
    • v.40 no.11
    • /
    • pp.814-822
    • /
    • 2017
  • Meiotic homologous recombination generates new combinations of preexisting genetic variation and is a crucial process in plant breeding. Within the last decade, our understanding of plant meiotic recombination and genome diversity has advanced considerably. Innovation in DNA sequencing technology has led to the exploration of high-resolution genetic and epigenetic information in plant genomes, which has helped to accelerate plant breeding practices via high-throughput genotyping, and linkage and association mapping. In addition, great advances toward understanding the genetic and epigenetic control mechanisms of meiotic recombination have enabled the expansion of breeding programs and the unlocking of genetic diversity that can be used for crop improvement. This review highlights the recent literature on plant meiotic recombination and discusses the translation of this knowledge to the manipulation of meiotic recombination frequency and location with regards to crop plant breeding.

Type 1 diabetes genetic susceptibility markers and their functional implications

  • Park, Yongsoo
    • Journal of Genetic Medicine
    • /
    • v.11 no.1
    • /
    • pp.1-10
    • /
    • 2014
  • Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by selective destruction of pancreatic ${\beta}$-cells resulting in insulin deficiency. The genetic determinants of T1D susceptibility have been linked to several loci, in particular to the human leukocyte antigen (HLA) region, which accounts for 50% of the genetic risk of developing T1D. Multiple genes in the HLA region, which are in strong linkage disequilibrium, are thought to be involved. Another important locus, with a smaller effect on genetic predisposition to T1D, is the insulin gene. The advent of numerous single nucleotide polymorphism markers and genome screening has enabled the identification of dozens of new T1D susceptibility loci. Some of them appear to predispose to T1D independently of the HLA and may be important in families with T1D who lack strong HLA susceptibility. Other loci may interact with each other to cause susceptibility. The autoimmune response against ${\beta}$-cells can also be triggered by environmental factors in the presence of a predisposing genetic background. Deciphering the environmental and genetic factors involved should help to understand the origin of T1D and aid in the design of individualized prevention programs.

Linkage Disequilibrium of Dopamine D2 Receptor Gene in the Korean Population

  • Kang, Byung-Yong;Oh, Sang-Duk;Lee, Kang-Oh
    • Toxicological Research
    • /
    • v.20 no.1
    • /
    • pp.49-53
    • /
    • 2004
  • The genetic basis of hypertension is complex, and has been considered to be associated with the dopamine D2 receptor gene (DD2R). Because association studies using the candidate gene approach may provide important clues regarding the pathogenesis of hypertension and establish basis for further study, we performed the association study on the relationship between genetic polymorphisms in the DD2R gene and hypertension in Koreans. Eighty nine patients with hypertension and 86 age-matched subjects with normal blood pressure were enrolled. Genomic DNA was extracted from peripheral blood leukocytes. PCR-RFLP analysis was performed to detect the three polymorphic Taq I sites in the DD2R gene. There were no significant differences in genotype, allele and haplotype distributions of any polymorphisms in the DD2R gene between two groups, respectively (P>0.05), although significant linkage disequilibriums among these polymorphic sites were detected by pair-wise analysis (P<0.05). Therefore, our negative result suggest that the three Taq I RFLPs in the DD2R gene were not significantly associated with hypertension in Koreans.

Bayesian bi-level variable selection for genome-wide survival study

  • Eunjee Lee;Joseph G. Ibrahim;Hongtu Zhu
    • Genomics & Informatics
    • /
    • v.21 no.3
    • /
    • pp.28.1-28.13
    • /
    • 2023
  • Mild cognitive impairment (MCI) is a clinical syndrome characterized by the onset and evolution of cognitive impairments, often considered a transitional stage to Alzheimer's disease (AD). The genetic traits of MCI patients who experience a rapid progression to AD can enhance early diagnosis capabilities and facilitate drug discovery for AD. While a genome-wide association study (GWAS) is a standard tool for identifying single nucleotide polymorphisms (SNPs) related to a disease, it fails to detect SNPs with small effect sizes due to stringent control for multiple testing. Additionally, the method does not consider the group structures of SNPs, such as genes or linkage disequilibrium blocks, which can provide valuable insights into the genetic architecture. To address the limitations, we propose a Bayesian bi-level variable selection method that detects SNPs associated with time of conversion from MCI to AD. Our approach integrates group inclusion indicators into an accelerated failure time model to identify important SNP groups. Additionally, we employ data augmentation techniques to impute censored time values using a predictive posterior. We adapt Dirichlet-Laplace shrinkage priors to incorporate the group structure for SNP-level variable selection. In the simulation study, our method outperformed other competing methods regarding variable selection. The analysis of Alzheimer's Disease Neuroimaging Initiative (ADNI) data revealed several genes directly or indirectly related to AD, whereas a classical GWAS did not identify any significant SNPs.

Mapping of the Porcine Calpastatin Gene and Association Study of Its Variance with Economic Traits in Pigs

  • Choi, B.H.;Lee, J.S.;Jang, G.W.;Lee, H.Y.;Lee, J.W.;Lee, K.T.;Chung, H.Y.;Park, H.S.;Oh, S.J.;Sun, S.S.;Myung, K.H.;Cheong, I.C.;Kim, T.H.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.19 no.8
    • /
    • pp.1085-1089
    • /
    • 2006
  • The objectives of this study were to confirm a location of the calpastatin (CAST) gene in chromosome 2 and to detect associations of genetic variations with economic traits in the porcine CAST gene as a candidate gene for growth and meat quality traits in pigs. Calpastatin is a specific endogenous inhibitor of calpains. The calpain protease system is ubiquitous, and is involved in numerous growth and metabolic processes. Three single nucleotide variations were identified within a 1.6 kb fragment of the porcine CAST gene and these polymorphisms were used for genetic linkage mapping. Linkage and QTL mapping were performed with the National Livestock Research Institute (NLRI) reference families using eight microsatellites and SNP makers in the CAST gene. The porcine CAST gene was mapped adjacent to the markers, SW395 and SW1695 on SSC2 with LOD scores of 15.32 and 8.50, respectively. According to the QTL mapping, a significant association was detected at 82 cM between SW395 and CAST-Hinf I for weight at the age of 30 weeks. In addition, an association study was performed with the $F_2$ animals of NLRI reference families for Hinf I, Msp I and Rsa I polymorphisms in the CAST gene. Two polymorphisms, CAST-Rsa I and CAST-Hinf I, showed significant correlation for growth traits at p<0.01 and p<0.05, respectively.

Comparative assessment of the effective population size and linkage disequilibrium of Karan Fries cattle revealed viable population dynamics

  • Shivam Bhardwaj;Oshin Togla;Shabahat Mumtaz;Nistha Yadav;Jigyasha Tiwari;Lal Muansangi;Satish Kumar Illa;Yaser Mushtaq Wani;Sabyasachi Mukherjee;Anupama Mukherjee
    • Animal Bioscience
    • /
    • v.37 no.5
    • /
    • pp.795-806
    • /
    • 2024
  • Objective: Karan Fries (KF), a high-producing composite cattle was developed through crossing indicine Tharparkar cows with taurine bulls (Holstein Friesian, Brown Swiss, and Jersey), to increase the milk yield across India. This composite cattle population must maintain sufficient genetic diversity for long-term development and breed improvement in the coming years. The level of linkage disequilibrium (LD) measures the influence of population genetic forces on the genomic structure and provides insights into the evolutionary history of populations, while the decay of LD is important in understanding the limits of genome-wide association studies for a population. Effective population size (Ne) which is genomically based on LD accumulated over the course of previous generations, is a valuable tool for e valuation of the genetic diversity and level of inbreeding. The present study was undertaken to understand KF population dynamics through the estimation of Ne and LD for the long-term sustainability of these breeds. Methods: The present study included 96 KF samples genotyped using Illumina HDBovine array to estimate the effective population and examine the LD pattern. The genotype data were also obtained for other crossbreds (Santa Gertrudis, Brangus, and Beefmaster) and Holstein Friesian cattle for comparison purposes. Results: The average LD between single nucleotide polymorphisms (SNPs) was r2 = 0.13 in the present study. LD decay (r2 = 0.2) was observed at 40 kb inter-marker distance, indicating a panel with 62,765 SNPs was sufficient for genomic breeding value estimation in KF cattle. The pedigree-based Ne of KF was determined to be 78, while the Ne estimates obtained using LD-based methods were 52 (SNeP) and 219 (genetic optimization for Ne estimation), respectively. Conclusion: KF cattle have an Ne exceeding the FAO's minimum recommended level of 50, which was desirable. The study also revealed significant population dynamics of KF cattle and increased our understanding of devising suitable breeding strategies for long-term sustainable development.

Genetic Algorithm based hyperparameter tuned CNN for identifying IoT intrusions

  • Alexander. R;Pradeep Mohan Kumar. K
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.18 no.3
    • /
    • pp.755-778
    • /
    • 2024
  • In recent years, the number of devices being connected to the internet has grown enormously, as has the intrusive behavior in the network. Thus, it is important for intrusion detection systems to report all intrusive behavior. Using deep learning and machine learning algorithms, intrusion detection systems are able to perform well in identifying attacks. However, the concern with these deep learning algorithms is their inability to identify a suitable network based on traffic volume, which requires manual changing of hyperparameters, which consumes a lot of time and effort. So, to address this, this paper offers a solution using the extended compact genetic algorithm for the automatic tuning of the hyperparameters. The novelty in this work comes in the form of modeling the problem of identifying attacks as a multi-objective optimization problem and the usage of linkage learning for solving the optimization problem. The solution is obtained using the feature map-based Convolutional Neural Network that gets encoded into genes, and using the extended compact genetic algorithm the model is optimized for the detection accuracy and latency. The CIC-IDS-2017 and 2018 datasets are used to verify the hypothesis, and the most recent analysis yielded a substantial F1 score of 99.23%. Response time, CPU, and memory consumption evaluations are done to demonstrate the suitability of this model in a fog environment.

Genome-wide Linkage Study for Plasma HDL Cholesterol Level in an Isolated Population of Mongolia

  • Park, Han-Soo;Kim, Jong-Il;Cho, Sung-Il;Sung, Joo-Hon;Kim, Hyung-Lae;Ju, Young-Seok;Bayasgalan, Gombojav;Lee, Mi-Kyeong;Seo, Jeong-Sun
    • Genomics & Informatics
    • /
    • v.6 no.1
    • /
    • pp.8-13
    • /
    • 2008
  • High-density lipoprotein (HDL) whose primary role is to transport cholesterol from peripheral tissues to the liver, is associated with the incidence of coronary heart disease. We analyzed HDL cholesterol levels in a genetically isolated population of extended Mongolian families. A total of 1002 individuals (54.5% women) from 95 families were enrolled. After genotyping by use of 1000 microsatellite markers, we performed a genome-wide linkage search with variance component analysis. The estimated heritability of HDL cholesterol was 0.45, revealing that HDL cholesterol was under significant genetic influence. We found peak evidence of linkage (LOD score=1.88) for HDL cholesterol level on chromosome 6 (nearest marker D6S1660) and potential evidences for linkage on chromosomes 1, 12 and 19 with the LOD scores of 1.32, 1.44 and 1.14, respectively. These results should pave the way for the discovery of the relevant genes by fine mapping and association analysis.