• BMB Reports
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• 제51권2호
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• pp.55-56
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• 2018

Long terminal repeat retrotransposons (LTR-Rs) are major elements creating new genome structure for expansion of plant genomes. However, in addition to the genome expansion, the role of LTR-Rs has been unexplored. In this study, we constructed new reference genome sequences of two pepper species (Capsicum baccatum and C. chinense), and updated the reference genome of C. annuum. We focused on the study for speciation of Capsicum spp. and its driving forces. We found that chromosomal translocation, unequal amplification of LTR-Rs, and recent gene duplications in the pepper genomes as major evolutionary forces for diversification of Capsicum spp. Specifically, our analyses revealed that the nucleotide-binding and leucine-rich-repeat proteins (NLRs) were massively created by LTR-R-driven retroduplication. These retoduplicated NLRs were abundant in higher plants, and most of them were lineage-specific. The retroduplication was a main process for creation of functional disease-resistance genes in Solanaceae plants. In addition, 4-10% of whole genes including highly amplified families such as MADS-box and cytochrome P450 emerged by the retroduplication in the plants. Our study provides new insight into creation of disease-resistance genes and high-copy number gene families by retroduplication in plants.

• 식물병연구
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• 제26권1호
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• pp.38-43
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• 2020

The genome of the rice blast fungus Magnaporthe oryzae contains several types of transposable elements (TEs), and some TEs cause genetic variation that allows M. oryzae to evade host detection. We studied how five abundant TEs in rice pathogens, Pot3, Pot2, MAGGY, Line-like element (MGL) and Mg-SINE, are expressed under diverse conditions related to growth, development, and stress. Expression of Pot3 and Pot2 was activated in germinated conidia and mycelia treated with tricyclazole. Retrotransposon MAGGY was highly expressed in appressoria and tricyclazole-treated mycelia. MAGGY and Pot2 were also activated during the early and late stages of perithecia development. MGL was up-regulated in conidia and during conidial germination but not during appressorium formation. No noticeable expression of Mg-SINE was observed under most conditions. Our results should help investigate if and how condition-specific expressions of some TEs contribute to the biology and evolution of M. oryzae.

• 한국미생물·생명공학회지
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• 제32권4호
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• pp.356-361
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• 2004

The ethionine resisconferring gene (ERCI) was constitutively expressed under the control of the alcohol dehydrogenase gene promoter (ADClp) and introduced into the chromosomes of an industrial polyploid strain of Saccharocerevisiae by using the 8-sequences of the Tyl retrotransposon as the recombination site. 8-Integrative cassette devoid of bacterial DNA sequences containing the ampicillin resistance gene was constructed that had the aureobasidin A resistance gene (AURl-C) as the selection marker and ERCl gene. The ERCl gene was also employed as the selection marker in the 8-integrative cassette lacking the A URl-C gene. Industrial Saccerevisiae transformed with these integrative cassettes exhibited strong resistance to DL-ethioncompared with nontransformants.

• 식물병연구
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• 제24권2호
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• pp.87-98
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• 2018

곰팡이 종들은 유전체내에 대략 10% 정도의 다양한 전이인자와 함께 반복적인 염기서열을 갖는다. 이러한 전이인자들의 대부분은 유전체내에서 활발히 전이되며 곰팡이 병원균의 기주 범위와도 연관성을 갖으며 분포하는 것으로 알려져있다. 화본과 작물에 병을 일으키는 도열병에 분포하는 전이인자들은 활발히 전이하는 것으로 보이며, 특정 기주에 감염하는 개체군에 특이적으로 분포하는 경우가 많았다. 다수의 연구 보고에서도열병균의 전이인자가 비병원성 유전자의 기능을 상실하는데 작용하여, 이로인해 저항성 품종에 병을 일으켰다. 따라서, 도열병균의 전이인자들은 식물-곰팡이 사이의 상호 진화를 유도하는 원동력 중 하나일 수 있다. 본 총설에서는 도열병균에 존재하는 전이인자들의 종류와 생물학적인 기능에 관해 정리하였다.

• Genomics & Informatics
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• 제14권3호
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• pp.70-77
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• 2016

Transposable elements are one of major sources to cause genomic instability through various mechanisms including de novo insertion, insertion-mediated genomic deletion, and recombination-associated genomic deletion. Among them is Alu element which is the most abundant element, composing ~10% of the human genome. The element emerged in the primate genome 65 million years ago and has since propagated successfully in the human and non-human primate genomes. Alu element is a non-autonomous retrotransposon and therefore retrotransposed using L1-enzyme machinery. The 'master gene' model has been generally accepted to explain Alu element amplification in primate genomes. According to the model, different subfamilies of Alu elements are created by mutations on the master gene and most Alu elements are amplified from the hyperactive master genes. Alu element is frequently involved in genomic rearrangements in the human genome due to its abundance and sequence identity between them. The genomic rearrangements caused by Alu elements could lead to genetic disorders such as hereditary disease, blood disorder, and neurological disorder. In fact, Alu elements are associated with approximately 0.1% of human genetic disorders. The first part of this review discusses mechanisms of Alu amplification and diversity among different Alu subfamilies. The second part discusses the particular role of Alu elements in generating genomic rearrangements as well as human genetic disorders.

• 한국자원식물학회지
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• 제20권6호
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• pp.491-498
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• 2007

It has been hypothesized that efficient exclusion of methylated retrotransposons and repeated DNA region is one of the rapid and cost-effective approaches for comprehensive gene discovery in large genome size of maize. Three kinds of methylation-sensitive restriction enzymes, HapII, MspI and McrBC, were used to identify the restriction frequency of cytosine methylation sites in maize genome. Roughly 60% of total maize genomic DNA was restricted less than 500bp by McrBC, and the most of restricted small size fraction was composed retrotransposon. In order to validate the efficient construction of gene-rich shotgun library, we compare two gene-rich methyl-filtration shotgun libraries using in vivo and in vitro methyl-filtration system. The size selected DNA fraction by Sau3A-McrBC enzyme treated was very stable and has not appeared modification in E. coli, but most insert DNA size of partially digested with Sau3A were decrease less than 500bp by bacterial methylation-modification system. In compare of retroelements portion, A 44.6% of the sequences were retroelement in unmethyl-filtered library, and the most of them was Copia type, such as Prem, Opie and Ji. The portion of retroelement was drastically decreased to 25% and 20% by in vivo and in vitro filtration system, respectively.

• 한국자원식물학회지
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• 제27권3호
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• pp.236-241
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• 2014

A sex-linked random amplified polymorphic DNA (RAPD) marker was identified from Asparagus officinalis L. and was converted into a sequence-characterized amplified regions (SCAR) marker for the large-scale screening of male and female plants. A total of 100 arbitrary decamer oligonucleotide primers were used for the RAPD analysis. Among them, the primer UBC347 amplified one female-specific 400 base pair DNA. Subsequently, the amplified RAPD fragment was cloned and sequenced. The fragment was abundant in AT and shared sequence homology with retrotransposon elements. On the basis of the sequence obtained, a pair of SCAR primer was designed. The amplification product, named F400, was the same size as the respective RAPD fragment from which it was derived. The F400 SCAR marker resulted to be female-specific in the three asparagus varieties tested in this study. This SCAR marker can be used for an early and rapid identification of female and male plants during breeding programs of asparagus.

• 미생물학회지
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• 제41권2호
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• pp.146-151
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• 2005

전분 이용이 가능한 산업용 Saccharomyces cerevisiae균주를 개발하기 위해 alcohol dehydrogenase 유전자 프로모터(ADClp)의 조절하에 발현되는 Aspergillus awamori glucoamylase cDNA 유전자(GA1)를 산업용 S. cerevisiae의 염색체에 도입하였다. 산업적 이용에 적합한 효모균주를 얻기 위해 세균 ampicillin 저항성 유전자가 제거되고 GA1 유전자와 선별 표지유전자로 S. cerevisiae aureobasidin A 저항성 유전자(AUR1-C)와 재조합 부위로 Tyretrotransposon $\delta$-서열이 포함된 integrative cassette를제조하였다. 이 $\delta-integrative$ cassette로 형질전환된 산업용 S. cerevisiae는 배지상에 glucoamylase를 생산 분비하였고 전환을 유일한 탄소원으로 하여 생장하였다. 형질전환체를 비선택배지에서 배양했을 매 삽입된 GA1유전자가 100세대까지 안정되게 유지되었다.

• 한국작물학회지
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• 제49권4호
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• pp.358-362
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• 2004

In order to develop molecular markers related to stay green phenotype, AFLP analysis was conducted using near-isogenic lines for either stay green or non stay green trait. Both lines have characteristics of multi-ear and tillers (MET). Two out of 64 primer combinations of selective amplification identified three reproducible polymorphic fragments in MET corn with stay green. Both of E+AGC/M+CAC and E+AAG/M+CAA primer combinations produced two and one specific polymorphic fragments linked to stay green trait, respectively. For the conversion of AFLPs to sequence tag sites (STSs), primers were designed form both end sequences of each two polymorphic fragments. One fragment, which was amplified with E+AAG/M+CAA primer combinations, possessed 298 bp long and showed a $91\%$ homology with maize retrotransposon Cinful-l. One out of two polymorphic fragments produced with E+AGC/M+CAC primer combination had 236 bp long and matched a $96\%$ homology with an intron region of 22kDa alpha zein gene cluster in Zea mays. One out of two PCR fragments amplified with MET2 primer set in the stay green MET was not produced in the non-stay green MET. The developed AFLP and STS marker could be used as an efficient tool for selection of the stay green trait in the MET inbred.

• BMB Reports
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• 제43권9호
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• pp.635-641
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• 2010

Piwi proteins and Piwi-interacting RNAs (piRNAs) have been implicated in transposon control in germline from Drosophila to mammals. To examine the profile of small RNA expression in human cancer cells and explore difference in small RNA transcriptome, small RNA libraries prepared from wildtype, HILI overexpressed and HILI knockdowned Hela cells were sequenced using Solexa technology. piRNAs and other repeat-associated small RNAs were observed in Hela cells. By using in situ hybridization, piR-49322 was localized in the nucleolus and around the periphery of nuclear membrane in Hela cells. Following the overexpression of HILI, the retrotransposon elements LINE1 was significantly repressed, while LINE1-associated small RNAs decreased in abundance. The present study demonstrated that HILI along with piRNAs plays a role in LINE1 suppression in Hela cancer cell line.