• 제목/요약/키워드: Molecular evolution

검색결과 529건 처리시간 0.03초

Molecular genetic analysis of phytochelatin synthase genes in Arabidopsis

  • Ha, Suk-Bong
    • 한국식물학회:학술대회논문집
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    • 한국식물학회 2002년도 춘계학술발표대회:발표눈문요지록
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    • pp.62-72
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    • 2002
  • This study has investigated the biosynthesis and function of the heavy metal binding peptides, the phytochelatins, in plants. PCs are synthesised enzymatically from glutathione by the enzyme PC synthase in the presence of heavy metal ions. Using Arabidopsis thaliana as a model organism cadmium-sensitive, phytochelatin-deficient mutants have been isolated and characterised in previous studies. The cadl mutants have wildtype levels of glutathione, are PC deficient and lack PC synthase activity. Thus, the CADl gene has been proposed to encode PC synthase. The CADl gene was isolated by a positional cloning strategy The gene was mapped and a candidate identified. Each of four cadl mutants had a single base pair change in the candidate gene and the cadmium-sensitive, cadl phenotype was complemented by the candidate gene. This demonstrated the CADl gene had been cloned. A homologous gene in the fission yeast, Schizosaccharomyces pombe was identified through database searches. A targeted-deletion mutation of this gene was constructed and the mutant, like cadl mutants of Arabidopsis, was cadmium-sensitive and PC-deficient. A comparison of the redicted amino acid sequences reveals a highly conserved N-terminal region Presumed to be the catalytic domain and a variable C-terminal region containing multiple Cys residues proposed to be involved in activation of the enzyme by metal ions. Similar genes were also identified in animal species. The Arabidopsis CADl/AtPCSl and S. pombe SpbPCS genes were expressed in E. coli and were shown to be sufficient for glutathione-dependent, heavy metal activate PC synthesis in vitro, thus demonstrating these genes encode PC synthase enzymes. Using RT-PCR, AtPCSl expression appeared to be independent of Cd exposure. However, at higher levels of Cd exposure a AtPCSl-CUS reporter gene construct appeared to be more highly expressed. Using the reporter gene construct, AtPCSl was expressed most tissues. Expression appeared to be greater in younger tissues and same higher levels of expression was observed in some regions, including carpels and the base of siliques. AtPCS2 was a functional gene encoding an active PC synthase. However, its Pattern of expression and the phenotype of a mutant (or antisense line) have not been determined. Assuming the gene is functional then it has clearly been maintained through evolution and must provide some selective advantage. This implies that, at least in some cells or tissue, it is likely to be the dominant PC synthase expressed. This remains to be determined

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A refined Panax ginseng karyotype based on an ultra-high copy 167-bp tandem repeat and ribosomal DNAs

  • Waminal, Nomar Espinosa;Choi, Hong-Il;Kim, Nam-Hoon;Jang, Woojong;Lee, Junki;Park, Jee Young;Kim, Hyun Hee;Yang, Tae-Jin
    • Journal of Ginseng Research
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    • 제41권4호
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    • pp.469-476
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    • 2017
  • Background: Panax ginseng Meyer (Asian ginseng) has a large nuclear genome size of > 3.5 Gbp in haploid genome equivalent of 24 chromosomes. Tandem repeats (TRs) occupy significant portions of the genome in many plants and are often found in specific genomic loci, making them a valuable molecular cytogenetic tool in discriminating chromosomes. In an effort to understand the P. ginseng genome structure, we characterized an ultrahigh copy 167-bp TR (Pg167TR) and explored its chromosomal distribution as well as its utility for chromosome identification. Methods: Polymerase chain reaction amplicons of Pg167TR were labeled, along with 5S and 45S rDNA amplicons, using a direct nick-translation method. Direct fluorescence in situ hybridization (FISH) was used to analyze the chromosomal distribution of Pg167TR. Results: Recently, we reported a method of karyotyping the 24 chromosome pairs of P. ginseng using rDNA and DAPI (4',6-diamidino-2-phenylindole) bands. Here, a unique distribution of Pg167TR in all 24 P. ginseng chromosomes was observed, allowing easy identification of individual homologous chromosomes. Additionally, direct labeling of 5S and 45S rDNA probes allowed the identification of two additional 5S rDNA loci not previously reported, enabling the refinement of the P. ginseng karyotype. Conclusion: Identification of individual P. ginseng chromosomes was achieved using Pg167TR-FISH. Chromosome identification is important in understanding the P. ginseng genome structure, and our method will be useful for future integration of genetic linkage maps and genome scaffold anchoring. Additionally, it is a good tool for comparative studies with related species in efforts to understand the evolution of P. ginseng.

ITS 염기서열에 의한 한국산 쥐손이풀속(Geranium)의 계통학적 연구 (Phylogenetic study of Korean Geranium(Geraniaceae) based on nrDNA ITS squences)

  • 우정현;박선주
    • 식물분류학회지
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    • 제36권2호
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    • pp.91-108
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    • 2006
  • 한국산 Geranium(쥐손이풀속) 16분류군과 3개의 군외군을 대상으로 진화와 유연관계를 평가하기 위하여 nuclear ribosomal DNA 중 internal transcribed spacer (ITS) 구간에 대한 계통 분류학적 분석을 수행하였다. 계통 분류학적 연구들은 bootstrapping, jackknifing을 포함한 parsimony 방법과 neighbor-joining 방법을 사용하였다. 그 결과 한국산 쥐손이풀속은 단계통군을 형성하였다. Parsimony tree에서 한라이질풀은 가장 기부에 위치하였으며 Erianthum group은 높은 지지도에 의해 하나의 분계조를 형성하였다(100% bootstrap과 jackknife values). Krameri group인 산쥐손이는 Palustre group인 섬쥐손이와 가까이 위치하였으나 그 지지도는 매우 낮았고(37% bootstrap과 44% jackknife values) strict tree에서는 clade가 붕괴되었다. Wilfordii group에 분류되었던 큰세잎쥐손이는 Koreanum group과 가까이 위치하였고, Sibiricum group인 쥐손이풀은 Krameri group인 삼쥐손이와 가까이 위치하였으며 또한 이 두 종은 역시 Krameri group인 선이질풀과 자매군을 이루었다. Wilfordii group인 좀쥐손이와 세잎쥐손이는 Sibiricum group인 삼이질풀, 이질풀과 가까이 위치하였다. 이와 같은 결과는 많은 학자들에 의해 논란이 된 분류군들의 문제를 해결하는데 유용한 접근방법이라 생각되며, 전체 쥐손이풀속 수준에서의 계통분석에 유용한 도구로 이용될 수 있을 것으로 판단된다.

FOLLOW-UP OBSERVATIONS TOWARD PLANCK COLD CLUMPS WITH GROUND-BASED RADIO TELESCOPES

  • LIU, TIE;WU, YUEFANG;MARDONES, DIEGO;KIM, KEE-TAE;MENTEN, KARL M.;TATEMATSU, KEN;CUNNINGHAM, MARIA;JUVELA, MIKA;ZHANG, QIZHOU;GOLDSMITH, PAUL F;LIU, SHENG-YUAN;ZHANG, HUA-WEI;MENG, FANYI;LI, DI;LO, NADIA;GUAN, XIN;YUAN, JINGHUA;BELLOCHE, ARNAUD;HENKEL, CHRISTIAN;WYROWSKI, FRIEDRICH;GARAY, GUIDO;RISTORCELLI, ISABELLE;LEE, JEONG-EUN;WANG, KE;BRONFMAN, LEONARDO;TOTH, L. VIKTOR;SCHNEE, SCOTT;QIN, SHENGLI;AKHTER, SHAILA
    • 천문학논총
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    • 제30권2호
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    • pp.79-82
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    • 2015
  • The physical and chemical properties of prestellar cores, especially massive ones, are still far from being well understood due to the lack of a large sample. The low dust temperature (< 14 K) of Planck cold clumps makes them promising candidates for prestellar objects or for sources at the very initial stages of protostellar collapse. We have been conducting a series of observations toward Planck cold clumps (PCCs) with ground-based radio telescopes. In general, when compared with other star forming samples (e.g. infrared dark clouds), PCCs are more quiescent, suggesting that most of them may be in the earliest phase of star formation. However, some PCCs are associated with protostars and molecular outflows, indicating that not all PCCs are in a prestellar phase. We have identified hundreds of starless dense clumps from a mapping survey with the Purple Mountain Observatory (PMO) 13.7-m telescope. Follow-up observations suggest that these dense clumps are ideal targets to search for prestellar objects.

Alu-Derived Alternative Splicing Events Specific to Macaca Lineages in CTSF Gene

  • Lee, Ja-Rang;Park, Sang-Je;Kim, Young-Hyun;Choe, Se-Hee;Cho, Hyeon-Mu;Lee, Sang-Rae;Kim, Sun-Uk;Kim, Ji-Su;Sim, Bo-Woong;Song, Bong-Seok;Jeong, Kang-Jin;Lee, Youngjeon;Jin, Yeung Bae;Kang, Philyong;Huh, Jae-Won;Chan, Kyu-Tae
    • Molecules and Cells
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    • 제40권2호
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    • pp.100-108
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    • 2017
  • Cathepsin F, which is encoded by CTSF, is a cysteine proteinase ubiquitously expressed in several tissues. In a previous study, novel transcripts of the CTSF gene were identified in the crab-eating monkey deriving from the integration of an Alu element-AluYRa1. The occurrence of AluYRa1-derived alternative transcripts and the mechanism of exonization events in the CTSF gene of human, rhesus monkey, and crabeating monkey were investigated using PCR and reverse transcription PCR on the genomic DNA and cDNA isolated from several tissues. Results demonstrated that AluYRa1 was only integrated into the genome of Macaca species and this lineage-specific integration led to exonization events by producing a conserved 3' splice site. Six transcript variants (V1-V6) were generated by alternative splicing (AS) events, including intron retention and alternative 5' splice sites in the 5' and 3' flanking regions of CTSF_AluYRa1. Among them, V3-V5 transcripts were ubiquitously expressed in all tissues of rhesus monkey and crab-eating monkey, whereas AluYRa1-exonized V1 was dominantly expressed in the testis of the crab-eating monkey, and V2 was only expressed in the testis of the two monkeys. These five transcript variants also had different amino acid sequences in the C-terminal region of CTSF, as compared to reference sequences. Thus, species-specific Alu-derived exonization by lineage-specific integration of Alu elements and AS events seems to have played an important role during primate evolution by producing transcript variants and gene diversification.

Function and Molecular Ecology Significance of Two Catechol-Degrading Gene Clusters in Pseudomonas putida ND6

  • Shi, Sanyuan;Yang, Liu;Yang, Chen;Li, Shanshan;Zhao, Hong;Ren, Lu;Wang, Xiaokang;Lu, Fuping;Li, Ying;Zhao, Huabing
    • Journal of Microbiology and Biotechnology
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    • 제31권2호
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    • pp.259-271
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    • 2021
  • Many bacteria metabolize aromatic compounds via catechol as a catabolic intermediate, and possess multiple genes or clusters encoding catechol-cleavage enzymes. The presence of multiple isozyme-encoding genes is a widespread phenomenon that seems to give the carrying strains a selective advantage in the natural environment over those with only a single copy. In the naphthalene-degrading strain Pseudomonas putida ND6, catechol can be converted into intermediates of the tricarboxylic acid cycle via either the ortho- or meta-cleavage pathways. In this study, we demonstrated that the catechol ortho-cleavage pathway genes (catBICIAI and catBIICIIAII) on the chromosome play an important role. The catI and catII operons are co-transcribed, whereas catAI and catAII are under independent transcriptional regulation. We examined the binding of regulatory proteins to promoters. In the presence of cis-cis-muconate, a well-studied inducer of the cat gene cluster, CatRI and CatRII occupy an additional downstream site, designated as the activation binding site. Notably, CatRI binds to both the catI and catII promoters with high affinity, while CatRII binds weakly. This is likely caused by a T to G mutation in the G/T-N11-A motif. Specifically, we found that CatRI and CatRII regulate catBICIAI and catBIICIIAII in a cooperative manner, which provides new insights into naphthalene degradation.

기주식물 방어물질에 대한 담배나방의 생화학적 적응 (Biochemical Adaptation of the Oriental Tobacco Budworm, Helicoverpa assulta, to Host-plant Defensive Compounds)

  • 안승준
    • 한국응용곤충학회지
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    • 제61권1호
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    • pp.143-154
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    • 2022
  • 식물의 이차대사산물은 곤충-식물 상호관계에서 중요한 역할을 한다. 식식성 곤충은 식물의 방어물질에 대처하는 다양한 전략을 가지고 있다. 광식성 곤충은 넓은 범위의 다양한 식물들을 섭식하고 그 해독 기작도 보다 복잡한데, 이는 많은 종류의 식물유래 화합물에 반응하는 경향이 있기 때문으로 보인다. 이와는 달리 협식성 곤충은 몇몇 유사한 식물에 국한되어 살아가며 보다 효율적인 적응 방식을 지니고 있을 것으로 여겨진다. 이러한 협식성 곤충의 적응은 식물의 방어물질에 대한 해독효소를 다량 생산하거나 방어물질 또는 그 대사산물을 격리하는 전략을 마련하였기 때문으로 보인다. 담배나방은 담배와 고추 등 주로 가지과의 몇몇 식물만을 가해하는 협식성 곤충이다. 담배나방의 기주식물 적응성을 이해한다면, 이 해충에 의한 작물의 피해를 줄이는 방법을 개발하는데 도움을 줄 수 있을 뿐만 아니라, 담배나방과 같은 협식성 곤충의 생리, 생태, 진화를 연구하는 데에도 중요한 단서를 제공할 것이다. 본 종설에서는 담배나방의 기주식물 범위, 유충과 기주식물의 상호작용, 그리고 기주식물에서 특이적으로 나오는 니코틴과 캡사이신에 대한 곤충의 반응과 해독 메카니즘을 중심으로, 지난 반세기 동안의 연구결과를 요약하고 앞으로의 전망을 제시하고자 한다.

Phylogenetic and expression analysis of the angiopoietin-like gene family and their role in lipid metabolism in pigs

  • Zibin Zheng;Wentao Lyu;Qihua Hong;Hua Yang;Ying Li;Shengjun Zhao;Ying Ren;Yingping Xiao
    • Animal Bioscience
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    • 제36권10호
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    • pp.1517-1529
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    • 2023
  • Objective: The objective of this study was to investigate the phylogenetic and expression analysis of the angiopoietin-like (ANGPTL) gene family and their role in lipid metabolism in pigs. Methods: In this study, the amino acid sequence analysis, phylogenetic analysis, and chromosome adjacent gene analysis were performed to identify the ANGPTL gene family in pigs. According to the body weight data from 60 Jinhua pigs, different tissues of 6 pigs with average body weight were used to determine the expression profile of ANGPTL1-8. The ileum, subcutaneous fat, and liver of 8 pigs with distinct fatness were selected to analyze the gene expression of ANGPTL3, ANGPTL4, and ANGPTL8. Results: The sequence length of ANGPTLs in pigs was between 1,186 and 1,991 bp, and the pig ANGPTL family members shared common features with human homologous genes, including the high similarity of the amino acid sequence and chromosome flanking genes. Amino acid sequence analysis showed that ANGPTL1-7 had a highly conserved domain except for ANGPTL8. Phylogenetic analysis showed that each ANGPTL homologous gene shared a common origin. Quantitative reverse-transcription polymerase chain reaction analysis showed that ANGPTL family members had different expression patterns in different tissues. ANGPTL3 and ANGPTL8 were mainly expressed in the liver, while ANGPTL4 was expressed in many other tissues, such as the intestine and subcutaneous fat. The expression levels of ANGPTL3 in the liver and ANGPTL4 in the liver, intestine and subcutaneous fat of Jinhua pigs with low propensity for adipogenesis were significantly higher than those of high propensity for adipogenesis. Conclusion: These results increase our knowledge about the biological role of the ANGPTL family in this important economic species, it will also help to better understand the role of ANGPTL3, ANGPTL4, and ANGPTL8 in lipid metabolism of pigs, and provide innovative ideas for developing strategies to improve meat quality of pigs.

Molecular Characterization of an Isolate of Bean Common Mosaic Virus First Identified in Gardenia Using Metatranscriptome and Small RNA Sequencing

  • Zhong-Tian Xu;Hai-Tao Weng;Jian-Ping Chen;Chuan-Xi Zhang;Jun-Min Li;Yi-Yuan Li
    • The Plant Pathology Journal
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    • 제40권1호
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    • pp.73-82
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    • 2024
  • Gardenia (Gardenia jasminoides) is a popular and economically vital plant known for its ornamental and medicinal properties. Despite its widespread cultivation, there has been no documentation of plant viruses on gardenia yet. In the present study, gardenia leaves exhibiting symptoms of plant viral diseases were sampled and sequenced by both metatranscriptome and small RNA sequencing. As a consequence, bean common mosaic virus (BCMV) was identified in gardenia for the first time and named BCMV-gardenia. The full genome sequence of BCMV-gardenia is 10,054 nucleotides (nt) in length (excluding the poly (A) at the 3' termini), encoding a large polyprotein of 3,222 amino acids. Sequence analysis showed that the N-termini of the polyprotein encoded by BCMV-gardenia is less conserved when compared to other BCMV isolates, whereas the C-termini is the most conserved. Maximum likelihood phylogenetic analysis showed that BCMVgardenia was clustered closely with other BCMV isolates identified outside the leguminous plants. Our results indicated that the majority of BCMV-gardenia virus-derived small interfering RNAs (vsiRNAs) were 21 nt and 22 nt, with 21 nt being more abundant. The first nucleotide at the 5' termini of vsiRNAs derived from BCMV-gardenia preferred U and A. The ratio of vsiRNAs derived from sense (51.1%) and antisense (48.9%) strands is approaching, and the distribution of vsiRNAs along the viral genome is generally even, with some hot spots forming in local regions. Our findings could provide new insights into the diversity, evolution, and host expansion of BCMV and contribute to the prevention and treatment of this virus.

Bovine mastitis-associated Escherichia coli

  • Hong Qui Le;Se Kye Kim;Jang Won Yoon
    • 한국식품위생안전성학회지
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    • 제39권3호
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    • pp.181-190
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    • 2024
  • 소 유방염 관련 대장균(BMEC)은 생산되는 우유의 양과 품질을 변화시키고 도태율을 높임으로써 전 세계 낙농 산업에 심각한 재정적 손실을 초래할 수 있는 주요 원인 물질로 간주된다. 연구자, 수의사, 농부가 가장 효과적인 치료법과 진단 기술을 이해하고 결정하는 것은 젖소 유방염을 극복하는데 중요하다. 특히 무증상 혹은 준임상형 유방염의 경우, 소는 뚜렷한 증상을 보이지 않고, 장기간에 걸쳐 겉보기에 정상적인 우유를 계속 분비하여 원인 병원체인 대장균이 무리 내에서 감염을 퍼뜨릴 수 있다. 유방염 예방을 위해서는, 병원균의 유방 내 침입, 감염 확립, 유방의 염증의 3단계 병인 과정에 대한 이해가 필수적이다. 지금까지 대장균 유방염의 임상적 중증도에 기여하는 독성 인자와 병원성 사이에 명확한 상관관계가 발견되지 않았다. 다제내성 대장균과 새로운 내성 기전의 진화는 유방염 치료에 항생제를 광범위하게 사용하고 있기 때문에 문제시 되고 있는 실정이다. 따라서 BMEC 치료의 효능을 향상시키기 위해서는 대체제 발굴이 중요하다. 지난 30년 동안 소 유방염의 역학 조사를 위해 다양한 유전자형 분석 기술이 사용되었다. 이러한 연구는 BMEC 계통 간의 진화 관련성 뿐 아니라 기원, 전염 경로, 개체군 구조에 대한 이해를 크게 향상시켰다. 따라서 본 리뷰에서는 BMEC의 전반적 개요를 제공하여 병인, 유전적 관계, 발병 기전, 관리 및 질병 통제를 위한 새로운 치료 옵션에 대한 통찰력을 제공하고자 한다.