• Title/Summary/Keyword: Gene Selection

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Genetic Diversity and Characterization of DPE1 Gene in Rice Germplasm

  • Aueangporn Somsri;Yong-Jin Park
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2022년도 추계학술대회
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    • pp.220-220
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    • 2022
  • Disproportionating Enzyme 1 (DPE1) is an a-1,4-D-glucanotransferase that cleavages the a-1,4-glucosidic bonds and transfers glucosyl groups. In rice endosperm, it participates in starch synthesis by transferring maltooligosyl groups from amylose and amylopectin to amylopectin. Here, we investigated the haplotype variations and evolutionary indices (e.g., genetic diversity and population structure) for the DPE1 gene in 374 rice accessions representing seven subgroups (wild, indica, temperate japonica, tropical japonica, aus, aromatic, and admixture). Variant calling analysis of DPE1 coding regions leads to the identification of six functional haplotypes representing/occupying 8 nonsynonymous SNPs. Nucleotide diversity analysis revealed the highest pi-value in wild group (0.0556) compared to other cultivated groups, of which temperate japonica showed the most reduction of genetic diversity value (0.003). A significant positive Tajima's D value (1.6330) of admixture highlights sudden population contraction under balancing selection, while temperate japonica with the lowest Tajima's D value (-1.3523) showed a selection signature of DPE1 domestication which might be the cause of excess of rare alleles. Moreover, these two subpopulations exhibits a greater differentiation (FST=0.0148), indicating a higher genetic diversity. Our findings on functional DPE1 haplotypes will be useful in future breeding programs, and the evolutionary indices can also be applicable in functional studies of the DPE1 gene.

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Signatures of positive selection underlying beef production traits in Korean cattle breeds

  • Edea, Zewdu;Jung, Kyoung Sub;Shin, Sung-Sub;Yoo, Song-Won;Choi, Jae Won;Kim, Kwan-Suk
    • Journal of Animal Science and Technology
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    • 제62권3호
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    • pp.293-305
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    • 2020
  • The difference in the breeding programs and population history may have diversely shaped the genomes of Korean native cattle breeds. In the absence of phenotypic data, comparisons of breeds that have been subjected to different selective pressures can aid to identify genomic regions and genes controlling qualitative and complex traits. In this study to decipher genetic variation and identify evidence of divergent selection, 3 Korean cattle breeds were genotyped using the recently developed high-density GeneSeek Genomic Profiler F250 (GGP-F250) array. The three Korean cattle breeds clustered according to their coat color phenotypes and breeding programs. The Heugu breed reliably showed smaller effective population size at all generations considered. Across the autosomal chromosomes, 113 and 83 annotated genes were identified from Hanwoo-Chikso and Hanwoo-Heugu comparisons, respectively of which 16 genes were shared between the two pairwise comparisons. The most important signals of selection were detected on bovine chromosomes 14 (24.39-25.13 Mb) and 18 (13.34-15.07 Mb), containing genes related to body size, and coat color (XKR4, LYN, PLAG1, SDR16C5, TMEM68, CDH15, MC1R, and GALNS). Some of the candidate genes are also associated with meat quality traits (ACSF3, EIF2B1, BANP, APCDD1, and GALM) and harbor quantitative trait locus (QTL) for beef production traits. Further functional analysis revealed that the candidate genes (DBI, ACSF3, HINT2, GBA2, AGPAT5, SCAP, ELP6, APOB, and RBL1) were involved in gene ontology (GO) terms relevant to meat quality including fatty acid oxidation, biosynthesis, and lipid storage. Candidate genes previously known to affect beef production and quality traits could be used in the beef cattle selection strategies.

Machine Learning Perspective Gene Optimization for Efficient Induction Machine Design

  • Selvam, Ponmurugan Panneer;Narayanan, Rengarajan
    • Journal of Electrical Engineering and Technology
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    • 제13권3호
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    • pp.1202-1211
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    • 2018
  • In this paper, induction machine operation efficiency and torque is improved using Machine Learning based Gene Optimization (ML-GO) Technique is introduced. Optimized Genetic Algorithm (OGA) is used to select the optimal induction machine data. In OGA, selection, crossover and mutation process is carried out to find the optimal electrical machine data for induction machine design. Initially, many number of induction machine data are given as input for OGA. Then, fitness value is calculated for all induction machine data to find whether the criterion is satisfied or not through fitness function (i.e., objective function such as starting to full load torque ratio, rotor current, power factor and maximum flux density of stator and rotor teeth). When the criterion is not satisfied, annealed selection approach in OGA is used to move the selection criteria from exploration to exploitation to attain the optimal solution (i.e., efficient machine data). After the selection process, two point crossovers is carried out to select two crossover points within a chromosomes (i.e., design variables) and then swaps two parent's chromosomes for producing two new offspring. Finally, Adaptive Levy Mutation is used in OGA to select any value in random manner and gets mutated to obtain the optimal value. This process gets iterated till finding the optimal value for induction machine design. Experimental evaluation of ML-GO technique is carried out with performance metrics such as torque, rotor current, induction machine operation efficiency and rotor power factor compared to the state-of-the-art works.

누대도태에 의한 벼멸구의 품종적응성의 변화 (Changes in the Fitness of Brown Planthopper, Nilapawata lugens Stal (Homoptera: Delphacidae) to Several Resistant Rice Varieties after Multi-generational Selection)

  • 송유한;황인철;김진호
    • 한국응용곤충학회지
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    • 제41권2호
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    • pp.113-121
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    • 2002
  • 벼멸구를 저항성 품종에서 도태시켰을 때 새로운 생태형으로 발전되는 속도와 벼멸구의 생태형과 벼의 품종저항성 간에 유전적으로 대응하고 있는지를 알아보고자, 감수성품종(동진벼)으로 사육하던 벼멸구를 Bph1 gene을 가진 저항성품종(청청벼)으로 각각 3세대 및 6세대 도태시킨 후, 같은 Bph1 gene을 가진 4개 품종(Mudgo, IR26, IR64, 청청벼)과, 다른 bph2 gene을 가진 2개 품종(밀양63호 및 가야벼)및 저항성이 없는 2개 품종(동진벼, TN-1)을 공시하여 각 계통의 벼멸구의 산란 및 섭식선호성, 수명, 발육기간, 사충율, 산란수 등을 조사하였다. 그 결과 감수성 벼멸구(생태형-1)를 저항성 Bph1 유전자를 갖인 청청벼에서 3세대(청청3세대계)및 6세대(청청6세대계)로 도태시켰을 때, 사육세대가 많아질수록 청청벼에서의 성충의 수명은 길어지고, 산란수는 많아지며, 또한 약충의 우화율이 높아지고, 약충기간이 짧아지는 등 빠르게 저항성을 극복하였다. 청청3세대계 및 6세대계 벼멸구는 청청벼와 같은 Bph1저항성 유전자를 가진 다른 품종들(Mudgo, IR26, IR64)에 대해서도 도태세대수가 많아지면서 선호성이 점점 높아지는 경향이었다. 성충의 수명과 산란수에 있어서도 청청3세대계, 청청6세대계 등으로 도태세대가 많아질수록 같은 저항성 Bph1유전자를 가진 Mudgo, IR26, IR64등에서 수명이 길어지고 산란수도 많아졌다. 벼멸구의 약충기간은 품종과 벼멸구 도태계통간에 큰 차이가 없었다. 그러나, 약충기간 중 사망률은 도태가 진행되면서 역시 Bph1저항성 gene의 4개 품종 모두에서 낮아졌고, 죽은 개체의 수명도 길어졌다. 밀양 63호(bph2 gene)와 가야벼(Bph1+bph2 gene) 등 2개 품종에서는 벼멸구의 3개 계통 모두 우화하지 못했다.

Potential of the Quantitative Trait Loci Mapping Using Crossbred Population

  • Yang, Shulin;Zhu, Zhengmao;Li, Kui
    • Asian-Australasian Journal of Animal Sciences
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    • 제18권12호
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    • pp.1675-1683
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    • 2005
  • In the process of crossbreeding, the linkage disequilibria between the quantitative trait loci (QTL) and their linked markers were reduced gradually with increasing generations. To study the potential of QTL mapping using the crossbred population, we presented a mixed effect model that treated the mean allelic value of the different founder populations as the fixed effect and the allelic deviation from the population mean as random effect. It was assumed that there were fifty QTLs having effect on the trait variation, the population mean and variance were divided to each QTL in founder generation in our model. Only the additive effect was considered in this model for simulation. Six schemes (S1-S6) of crossbreeding were studied. The selection index was used to evaluate the synthetic breeding value of two traits of the individual in the scheme of S2, S4 and S6, and the individuals with high selection index were chosen as the parents of the next generation. Random selection was used in the scheme of S1, S3 and S5. In this study, we premised a QTL explained 40% of the genetic variance was located in a region of 20 cM by the linkage analysis previously. The log likelihood ratio (log LR) was calculated to determine the presence of a QTL at the particular chromosomal position in each of the generations from the fourth to twentieth. The profiles of log LR and the number of the highest log LR located in the region of 5, 10 and 20 cM were compared between different generations and schemes. The profiles and the correct number reduced gradually with the generations increasing in the schemes of S2, S4 and S6, but both of them increased in the schemes of S1, S3 and S5. From the results, we concluded that the crossbreeding population undergoing random selection was suitable for improving the resolution of QTL mapping. Even experiencing index selection, there was still enough variation existing within the crossbred population before the fourteenth generation that could be used to refine the location of QTL in the chromosome region.

Integrated transcriptomic analysis on small yellow follicles reveals that sosondowah ankyrin repeat domain family member A inhibits chicken follicle selection

  • Zhong, Conghao;Liu, Zemin;Qiao, Xibo;Kang, Li;Sun, Yi;Jiang, Yunliang
    • Animal Bioscience
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    • 제34권8호
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    • pp.1290-1302
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    • 2021
  • Objective: Follicle selection is an important process in chicken egg laying. Among several small yellow (SY) follicles, the one exhibiting the highest expression of follicle stimulation hormone receptor (FSHR) will be selected to become a hierarchal follicle. The role of lncRNA, miRNA and other non-coding RNA in chicken follicle selection is unclear. Methods: In this study, the whole transcriptome sequencing of SY follicles with different expression levels of FSHR in Jining Bairi hens was performed, and the expression of 30 randomly selected mRNAs, lncRNAs and miRNAs was validated by quantitative real-time polymerase chain reaction. Preliminary studies and bioinformatics analysis were performed on the selected mRNA, lncRNA, miRNA and their target genes. The effect of identified gene was examined in the granulosa cells of chicken follicles. Results: Integrated transcriptomic analysis on chicken SY follicles differing in FSHR expression revealed 467 differentially expressed mRNA genes, 134 differentially expressed lncRNA genes and 34 differentially expressed miRNA genes, and sosondowah ankyrin repeat domain family member A (SOWAHA) was the common target gene of three miRNAs and one lncRNA. SOWAHA was mainly expressed in small white (SW) and SY follicles and was affected by follicle stimulation hormone (FSH) treatment in the granulosa cells. Knockdown of SOWAHA inhibited the expression of Wnt family member 4 (Wnt4) and steroidogenic acute regulatory protein (StAR) in the granulosa cells of prehierarchal follicles, while stimulated Wnt4 in hierarchal follicles. Overexpression of SOWAHA increased the expression of Wnt4 in the granulosa cells of prehierarchal follicles, decreased that of StAR and cytochrome P450 family 11 subfamily A member 1 in the granulosa cells of hierarchal follicles and inhibited the proliferation of granulosa cells. Conclusion: Integrated analysis of chicken SY follicle transcriptomes identified SOWAHA as a network gene that is affected by FSH in granulosa cells of ovarian follicles. SOWAHA affected the expression of genes involved in chicken follicle selection and inhibited the proliferation of granulosa cells, suggesting an inhibitory role in chicken follicle selection.

Selection of Stable Reference Genes for Real-Time Quantitative PCR Analysis in Edwardsiella tarda

  • Sun, Zhongyang;Deng, Jia;Wu, Haizhen;Wang, Qiyao;Zhang, Yuanxing
    • Journal of Microbiology and Biotechnology
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    • 제27권1호
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    • pp.112-121
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    • 2017
  • Edwardsiella tarda is a gram-negative pathogenic bacterium in aquaculture that can cause hemorrhagic septicemia in fish. Many secreted proteins have already been identified as virulent factors of E. tarda. Moreover, since virulent phenotypes are based on the expression regulation of virulent genes, understanding the expression profile of virulent genes is important. A quantitative RT-PCR is one of the preferred methods for determining different gene expressions. However, this requires the selection of a stable reference gene in E. tarda, which has not yet been systematically studied. Accordingly, this study evaluated nine candidate reference genes (recA, uup, rpoB, rho, topA, gyrA, groEL, rpoD, and 16S rRNA) using the Excel-based programs BestKeeper, GeNorm, and NormFinder under different culture conditions. The results showed that 16S rRNA was more stable than the other genes at different culture growth phases. However, at the same culture time, topA was identified as the reference gene under the conditions of different strains, different culture media, and infection, whereas gyrA was identified under the condition of different temperatures. Thus, in experiments, the expression of gapA and fbaA in E. tarda was analyzed by RT-qPCR using 16S rRNA, recA, and uup as the reference genes. The results showed that 16S rRNA was the most suitable reference gene in this analysis, and that using unsuitable reference genes resulted in inaccurate results.

Efficient and Precise Construction of Markerless Manipulations in the Bacillus subtilis Genome

  • Yu, Haojie;Yan, Xin;Shen, Weiliang;Shen, Yujia;Zhang, Ji;Li, Shunpeng
    • Journal of Microbiology and Biotechnology
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    • 제20권1호
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    • pp.45-53
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    • 2010
  • We have developed an efficient and precise method for genome manipulations in Bacillus subtilis that allows rapid alteration of a gene sequence or multiple gene sequences without altering the chromosome in any other way. In our approach, the Escherichia coli toxin gene mazF, which was used as a counter-selectable marker, was placed under the control of a xylose-inducible expression system and associated with an antibiotic resistance gene to create a "mazF-cassette". A polymerase chain reaction (PCR)-generated fragment, consisting of two homology regions joined to the mazF-cassette, was integrated into the chromosome at the target locus by homologous recombination, using positive selection for antibiotic resistance. Then, the excision of the mazF-cassette from the chromosome by a single-crossover event between two short directly repeated (DR) sequences, included in the design of the PCR products, was achieved by counter-selection of mazF. We used this method efficiently and precisely to deliver a point mutation, to inactivate a specific gene, to delete a large genomic region, and to generate the in-frame deletion with minimal polar effects in the same background.

RNAseq 빅데이터에서 유전자 선택을 위한 밀집도-의존 정규화 기반의 서포트-벡터 머신 병합법 (Combining Support Vector Machine Recursive Feature Elimination and Intensity-dependent Normalization for Gene Selection in RNAseq)

  • 김차영
    • 인터넷정보학회논문지
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    • 제18권5호
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    • pp.47-53
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    • 2017
  • 고처리 시퀀싱과 빅데이터 및 크라우드 컴퓨팅에 혁신이 일어나면서, RNA 시퀀싱도 획기적인 변화가 일어, RNAseq가 기존의 DNA 마이크로어레이를 대체하여, 빅-데이터를 형성하고 있다. 현재, RANseq 이용한 유전자 조절망(GRN) 까지 연구가 활성화 되고 있는데, 그 중 한 분야가 GRN의 기본 요소인 특징 유전자를 빅-데이터에서도 구별하고 기존에 알려진 것 외에 새로운 역할을 찾는 것이다. 그러나, 이러한 연구 방향에 부합하는 빅-데이터를 처리할 수 있는 컴퓨테이션 방법이 아직까지 매우 부족하다. 따라서 본 논문에서는 RNAseq 빅-데이터를 처리할 수 있도록 기존의 SVM-RFE알고리즘을 밀집도-의존 정규화에 병합하여, NCBI-GEO와 같은 빅-데이터에서 공개된 일부의 데이터에 개선된 알고리즘을 적용하고 해당 알고리즘에 의해 나온 결과의 성능을 평가한다.