A twin ovary mutant derived from the doubled haploid (DH) progeny of a cross,02428/Gui 630, was presumably related to the transposition of some transposable elements. Up to date, all reported the active transposable ...A twin ovary mutant derived from the doubled haploid (DH) progeny of a cross,02428/Gui 630, was presumably related to the transposition of some transposable elements. Up to date, all reported the active transposable elements in rice (Oryza sativa L.) are copia like retrotransposons. In the present study, the reverse transcriptase domains of copia like retrotransposons were amplified from the total DNA isolated from the mutant plants with the degenerated oligonucleotide primers for the domain. Three cloned insert DNAs, R33 1, R33 4 and R33 8, representing putative different copia like retrotransposons were screened out. Two of them displayed high polymorphism between “Zhaiyeqing 8” and “Jingxi 17”. Nine of the polymorphic bands were mapped on seven rice chromosomes. Sequencing analysis revealed that stop codons frequently occur in the sequence of R33 8, while both R33 1 and R33 4 contain a continuous coding region for 81 putative amino acid residues. No significant variation in hybridization patterns was found between indica and japonica rice or among 26 varieties of indica rice when R33 1 was used as a probe. Nevertheless, when R33 4 was used as a probe, high polymorphisms were detected both between indica and japonica rice and among 26 indica varieties, implying that this element might still be active in rice genomes.展开更多
[Objective] To analyze genetic polymorphism of different species of wheat. [Method] The DNA of young seedlings from 21 species of wheat was isolated,and their genetic polymorphism was analyzed by inter-retrotransposon...[Objective] To analyze genetic polymorphism of different species of wheat. [Method] The DNA of young seedlings from 21 species of wheat was isolated,and their genetic polymorphism was analyzed by inter-retrotransposon amplified polymorphism （IRAP） using a molecule marker technology based on wheat retrotransposon Wis2-1 A. [Result] As shown by clustering map of the electrophoresis results,19 species of wheat assembled as cluster with different genetic distance. Most of the wheat species were distinguished. The genetic polymorphism among different species of wheat could be evaluated by this method objectively. [Conclusion] The analysis of IRAP based on wheat retrotransposon Wis2-1A could give a basis for breeding of wheat.展开更多
Retrotransposons account for a large proportion of the genome and genomic variation, and play key roles in creating novel genes and diversifying the genome in many eukaryotic species. Although retrotransposons are abu...Retrotransposons account for a large proportion of the genome and genomic variation, and play key roles in creating novel genes and diversifying the genome in many eukaryotic species. Although retrotransposons are abundant in plants, their roles had been underestimated because of a lack of research. Here, we characterized a gibberellin Acid (GA)-insensitive dwarf mutant, 84133, in foxtail millet. Map-based cloning revealed a 5.5-kb Copia-like retrotransposon insertion in DWARF1 (D1), which encodes a DELLA protein. Transcriptional analysis showed that the Copia retrotransposon mediated the transcriptional reprogramming of D1 leading to a novel N-terminal-deleted truncated DELLA transcript that was putatively driven by Copia's LTR, namely D1-TT, and another chimeric transcript. The presence of D1-TT was confirmed by protein immunodetection analysis. Furthermore, D1-TT protein was resistant to GA3 treatment compared with the intact DELLA protein due to its inability to interact with the GA receptor, SiGID1. Overexpression of D1-TT in foxtail millet resulted in dwarf plants, confirming that it determines the dwarfism of 84133. Thus, our study documents a rare instance of long terminal repeat (LTR) retrotransposon-mediated transcriptional reprograming in the plant kingdom. These results shed light on the function of LTR retrotransposons in generating new gene functions and genetic diversity.展开更多
One possible mechanism suggested for somaclonal variation is the activation of transposable elements. The activation of retrotransposons by stresses and external changes is commonly observed in plants. In previous stu...One possible mechanism suggested for somaclonal variation is the activation of transposable elements. The activation of retrotransposons by stresses and external changes is commonly observed in plants. In previous study, we isolated the reverse transcriptase （RT） gene sequences of Ty 1-copia retrotransposons from tissue culture strawberry （Fragaria x ananassa） plant, but not the transcriptionally active sequence. For further understanding the relationship between retrotransposon and somaclonal varation, in this study, we isolated the transcriptionally active RT gene sequences from strawberry plants subjected to different abiotic stresses. These retrotransposons were activated by spraying strawberry leaves with 2 mmol L^-1 salicylic acid （SA）, 50 mmol L^-1 methyl jasmonate （MeJA）, 50 mmol L^-1 abscisic acid （ABA）, 50 mmol L^-1 2,4- dichlorophenoxyacetic acid （2,4-D） or by inducing callus growth in 2 types of MS media： first medium supplemented with 0.5 mg L^-1 6-benzylaminopurine （6-BA）, 0.5 mg L^-1 gibberellic acid （GA3）, 1.0 mg L^-1 thidiazuron （TDZ）, and 0.1 mg L^-1 2,4-D, and the second medium supplemented with 0.5 mg L^-1 6-BA, 0.5 mg L^-1 GA3, 2.0 mg L^-1 TDZ, and 0.02 mg L^-1 indole butyric acid （1BA）. Analysis of gene sequences of 17 RTs revealed that none of them contained stop codons and/or indels disrupting the reading frame. These different stress-origin transcriptionally active RTs were remarkably similar to each other- FATEXP2-8 and FATEYS9-7 showed 100% sequence identity. Analysis of pylogenetic of these transcriptionally active RTs and the RT sequences from genome showed that there were close phylogenetic relationships of most of the transcriptionally active RTs. The results of this study have contributed to the background information necessary for future studies for evaluating the relationship between retrotransposons and somaclonal variation.展开更多
Retrotransposon-like elements are major constituents of most eukaryotic genomes. For example, they account for roughly 90% of the wheat （Triticum aestivum） genome, Previous study on a wheat strain treated by low-ene...Retrotransposon-like elements are major constituents of most eukaryotic genomes. For example, they account for roughly 90% of the wheat （Triticum aestivum） genome, Previous study on a wheat strain treated by low-energy N^＋ ions indicated the variations in AFLP （Amplified Fragment Length Polymorphism ） markers, One such variation was caused by the re-activation of Tyl-copia-like retrotransposons, implying that the mutagenic effects of lowenergy ions might work through elevated activation of retrotransposons, In this paper an expression profile of Tyl-copia-like retrotransposons in wheat treated by low-energy N^＋ ions is reported, The reverse transcriptase （RT） domains of these retrotransposons were amplified by reverse-transcriptional polymerase chain reaction （RT-PCR） and sequentially cloned, 42 and 65 clones were obtained from the treated （CL） and control materials （CK）, respectively, Sequence analysis of each clone was performed by software. Phylogeny and classification were calculated responding to the sequences of the RT domains. All the results show that there is much difference in the RT domain between the control sample and the treated sample, Especially, the RT domains from the treated group encode significantly more functional ORF （open reading frames） than those from the control sample, This observation suggests that the treated sample has higher activation of retrotransposons, possibly as a consequence of low-energy ion beam irradiation, It also suggests that retrotransposons in the two groups impact the host gene expression in two different ways and carry out different functions in wheat cells.展开更多
Retrotransposons are present in all plant genomes and play important roles in genome size,genome structure remodeling,gene function and genome evolution.Me07Em02 marked by sequence-related amplified polymorphism (SRAP...Retrotransposons are present in all plant genomes and play important roles in genome size,genome structure remodeling,gene function and genome evolution.Me07Em02 marked by sequence-related amplified polymorphism (SRAP) is verified,recovered,sequenced and analyzed,which closely link to the flesh color around the stone.By comparison with the peach genome Peach v1.0,a part of the sequence of copia-like retrotransposons is obtained.With the aid of DANMAN and DNASTAR sequence analysis software,BLASTn alignment is carried out in the peach genome database and GenBank.The whole genome sequence of the copialike retrotransposon in the peach is located at 9 939 764~9 944 771 bp in Scaffold-1 of Peach v1.0,with a total length of 5 008 bp.The LTR on both sides is exactly the same,the length is 444 bp,and the largest ORF box is located at the 487~4 545 bp of the sequence,encoding 1 535 amino acids.The amino acid sequence was submitted to GenBank for Protein BLAST alignment,The results showed that this sequence also has the typical amino acid sequence characteristics of the copia-like retrotransposon.At the same time,the method of peach retrotransposon labeling is preliminarily established,and the genetic diversity of the peach is analyzed.展开更多
A novel rice d1 mutant was identified using map-based cloning and comparative analysis of known dl mutants.The mutant[d1-a) shows a mild dwarf trait,which differs only slightly from the wildtype in plant height at the...A novel rice d1 mutant was identified using map-based cloning and comparative analysis of known dl mutants.The mutant[d1-a) shows a mild dwarf trait,which differs only slightly from the wildtype in plant height at the tillering stage.The dl-a mutant is different from other dl mutants.We found that it was interrupted by an Osr4 long terminal repeat(LTR)-retrotransposon,which resulted in the loss of exon 7 in the mutant D1 mRNA.A paralog of the D1 gene.D1-like,was revealed.D1-like is a truncated gene that might have resulted from recombination between retrotransposons.We identified 65 Osr4LTR-retrotransposons in Nipponbare,and found more LTR variants in contrast to coding DNA sequence(CDS) in the retrotransposons.We also identified five possible regulatory motifs in LTRs which may control the expression of the retrotransposons.In addition,we predicted six putative functional Osr4 retrotransposons that contain complete CDSs and all important elements.Osr4 retrotransposons were classified into 4 groups,and this type of retrotransposon only appears to be present in monocots.Members of group 1-1,which included all putative functional retrotransposons,showed a high similarity with each other.The retrotransposons were expressed in all tissues,at especially higher levels in some leaves and seeds.These findings imply that transpositions of group 1-1 members might have occurred frequently and recently.展开更多
We report the isolation of AtL1, a 249 bp non-LTR retrotransposon fragment from Arabidopsis thaliana by fingerprinting mRNAs extracted from A. thaliana plants, ecotype Columbia, in different heat stress conditions. So...We report the isolation of AtL1, a 249 bp non-LTR retrotransposon fragment from Arabidopsis thaliana by fingerprinting mRNAs extracted from A. thaliana plants, ecotype Columbia, in different heat stress conditions. Southern blot and PCR analysis suggested that AtL1 occurs as a single- or low-copy insert in the genome of A. thaliana ecotype Columbia. The presence of AtL1 in the genome of different Arabidopsis ecotypes was confirmed by PCR amplification and sequencing thus excluding all possible contamination. A preliminary scan of the AtL1 nucleotide sequence against the EMBL and NCBI databases revealed a high degree of similarity to a group of LINE type L1 retrotransposons of mammals and with a cDNA sequence of Artemisia annua. A phylogenetic analysis of LINE elements from animals and plants placed AtL1 and A. annua sequences in close proximity to some mammalian sequences but distant from the other plants LINE elements including those from Arabidopsis.展开更多
Mutagenesis and retrotransposons have a close relationship, but little attention has been paid yet to the activity of retrotransposons produced by physical mutagens. The variation of retrotransposon WIS 2-1A activity ...Mutagenesis and retrotransposons have a close relationship, but little attention has been paid yet to the activity of retrotransposons produced by physical mutagens. The variation of retrotransposon WIS 2-1A activity in wheat （Triticum aestivum L.） embryos at three different growth times （30 h, 45 h and 60 h） was investigated after they had been treated with N^＋ implantation in a vacuum of 5× 10^-2 Pa and irradiation by ^60Coγ-ray respectively. For each of the three growth times the expression of WIS 2-1A showed almost entirely a same trend of downregulation, upregulation, then downregulation, and upregulation again with the increase in dose of N^＋ implantation, but the expression appeared irregular with the increase in irradiation of ^60Coγ-ray. In conclusion, the acutely activating effect of WIS 2-1A stimulated by vacuum and high dose N^＋ implantation within a shorter incubation time may provide a convenient tool to advance the research on mutagenic breeding and function genes.展开更多
In order to identify the variation and estimate the genetic diversity among the fig (Ficus carica L.) genotypes collected from Algeria and Turkey, the genetic relationships between 86 genotypes were investigated using...In order to identify the variation and estimate the genetic diversity among the fig (Ficus carica L.) genotypes collected from Algeria and Turkey, the genetic relationships between 86 genotypes were investigated using 23 inter primer binding sites (iPBS)-retrotransposon and 16 simple sequence repeat (SSR) primers. A total of 63 polymorphic bands for the iPBS-retrotransposon markers and 25 alleles for the SSR markers were identified with an average of 2.7 and 1.6 per primer, respectively. The average value of polymorphism information content (PIC) for the iPBS markers (0.73) was higher than that for the SSR markers (0.69). Applying the neighbor-joining method to the combined iPBS-retrotransposon and SSR data, the fig genotypes were clustered into two groups. The STRUCTURE software was used to determine the population structure. Among the genotypes studied, two populations (K = 2) were identified indicating a low diversity between the Algerian and Turkish varieties. Both types of markers were able to differentiate all the fig genotypes and were efficient in discriminating the closely related genotypes. Our data also showed that as a universal marker, iPBS-retrotransposon is a useful tool for the molecular characterization of fig genotypes.展开更多
Retrotransposons,a type of DNA fragment that can mobilize itself on genome,can generate genetic variations and develop for molecular markers based on the insertion polymorphism.Zinc finger proteins(ZNFs)are among the ...Retrotransposons,a type of DNA fragment that can mobilize itself on genome,can generate genetic variations and develop for molecular markers based on the insertion polymorphism.Zinc finger proteins(ZNFs)are among the most abundant proteins in eukaryotic animals,and their functions are extraordinarily diverse and particularly important in gene regulation.In the current study,bioinformatic prediction was performed to screen for retrotransposon insertion polymorphisms(RIPs)in six ZNF genes(ZNF2,ZNF3,ZNF7,ZNF8,ZNF10 and ZNF12).Six RIPs in these ZNFs,including one short interspersed nuclear element(SINE)RIP in intron 1 and one long interspersed nuclear element 1(L1)RIP in intron 3 of ZNF2,one SINE RIP in 5′flanking region and one SINE RIP in intron 2 of ZNF3,one SINE RIP in 3′UTR of ZNF7 and one L1 RIP in intron 2 of ZNF12,were discovered and their presence was confirmed by PCR.The impact of the SINE RIP in the first intron of ZNF2,which is close to the core promoter of ZNF2,on the gene activity was investigated by dual-luciferase assay in three cell lines.Our results showed that the SINE insertion in the intron 1 of ZNF2 repressed the core promoter activity extremely significantly(P<0.01)in cervical cancer cells and porcine primary embryonic fibroblasts(HeLa and PEF),thus SINE may act as a repressor.This SINE RIP also significantly(P<0.05)affected the corrected back fat thickness in Yorkshire pigs.The corrected back fat thickness of individuals with SINE insertion in the first intron of ZNF2 was significantly(P<0.05)higher than that of individuals without SINE insertion.In summary,our data suggested that RIPs play important roles in the genetic variations of these ZNF genes and SINE RIP in the intron 1 of ZNF2 may provide a useful molecular marker for the screening of fat deposition in the pig breeding.展开更多
文摘A twin ovary mutant derived from the doubled haploid (DH) progeny of a cross,02428/Gui 630, was presumably related to the transposition of some transposable elements. Up to date, all reported the active transposable elements in rice (Oryza sativa L.) are copia like retrotransposons. In the present study, the reverse transcriptase domains of copia like retrotransposons were amplified from the total DNA isolated from the mutant plants with the degenerated oligonucleotide primers for the domain. Three cloned insert DNAs, R33 1, R33 4 and R33 8, representing putative different copia like retrotransposons were screened out. Two of them displayed high polymorphism between “Zhaiyeqing 8” and “Jingxi 17”. Nine of the polymorphic bands were mapped on seven rice chromosomes. Sequencing analysis revealed that stop codons frequently occur in the sequence of R33 8, while both R33 1 and R33 4 contain a continuous coding region for 81 putative amino acid residues. No significant variation in hybridization patterns was found between indica and japonica rice or among 26 varieties of indica rice when R33 1 was used as a probe. Nevertheless, when R33 4 was used as a probe, high polymorphisms were detected both between indica and japonica rice and among 26 indica varieties, implying that this element might still be active in rice genomes.
基金Supported by Natural Science Foundation of Educational Commission of Henan Province (2009B180019)~~
文摘[Objective] To analyze genetic polymorphism of different species of wheat. [Method] The DNA of young seedlings from 21 species of wheat was isolated,and their genetic polymorphism was analyzed by inter-retrotransposon amplified polymorphism （IRAP） using a molecule marker technology based on wheat retrotransposon Wis2-1 A. [Result] As shown by clustering map of the electrophoresis results,19 species of wheat assembled as cluster with different genetic distance. Most of the wheat species were distinguished. The genetic polymorphism among different species of wheat could be evaluated by this method objectively. [Conclusion] The analysis of IRAP based on wheat retrotransposon Wis2-1A could give a basis for breeding of wheat.
基金supported by the National Natural Science Foundation of China (31871634, 31500985)
文摘Retrotransposons account for a large proportion of the genome and genomic variation, and play key roles in creating novel genes and diversifying the genome in many eukaryotic species. Although retrotransposons are abundant in plants, their roles had been underestimated because of a lack of research. Here, we characterized a gibberellin Acid (GA)-insensitive dwarf mutant, 84133, in foxtail millet. Map-based cloning revealed a 5.5-kb Copia-like retrotransposon insertion in DWARF1 (D1), which encodes a DELLA protein. Transcriptional analysis showed that the Copia retrotransposon mediated the transcriptional reprogramming of D1 leading to a novel N-terminal-deleted truncated DELLA transcript that was putatively driven by Copia's LTR, namely D1-TT, and another chimeric transcript. The presence of D1-TT was confirmed by protein immunodetection analysis. Furthermore, D1-TT protein was resistant to GA3 treatment compared with the intact DELLA protein due to its inability to interact with the GA receptor, SiGID1. Overexpression of D1-TT in foxtail millet resulted in dwarf plants, confirming that it determines the dwarfism of 84133. Thus, our study documents a rare instance of long terminal repeat (LTR) retrotransposon-mediated transcriptional reprograming in the plant kingdom. These results shed light on the function of LTR retrotransposons in generating new gene functions and genetic diversity.
基金supported by the National Natural Sci-ence Foundation of China (30871689)the Program for New Century Excellent Talents in University, China(NCET-07-0565)Science Foundation from the Department of Education of Liaoning Province, China(20060772)
文摘One possible mechanism suggested for somaclonal variation is the activation of transposable elements. The activation of retrotransposons by stresses and external changes is commonly observed in plants. In previous study, we isolated the reverse transcriptase （RT） gene sequences of Ty 1-copia retrotransposons from tissue culture strawberry （Fragaria x ananassa） plant, but not the transcriptionally active sequence. For further understanding the relationship between retrotransposon and somaclonal varation, in this study, we isolated the transcriptionally active RT gene sequences from strawberry plants subjected to different abiotic stresses. These retrotransposons were activated by spraying strawberry leaves with 2 mmol L^-1 salicylic acid （SA）, 50 mmol L^-1 methyl jasmonate （MeJA）, 50 mmol L^-1 abscisic acid （ABA）, 50 mmol L^-1 2,4- dichlorophenoxyacetic acid （2,4-D） or by inducing callus growth in 2 types of MS media： first medium supplemented with 0.5 mg L^-1 6-benzylaminopurine （6-BA）, 0.5 mg L^-1 gibberellic acid （GA3）, 1.0 mg L^-1 thidiazuron （TDZ）, and 0.1 mg L^-1 2,4-D, and the second medium supplemented with 0.5 mg L^-1 6-BA, 0.5 mg L^-1 GA3, 2.0 mg L^-1 TDZ, and 0.02 mg L^-1 indole butyric acid （1BA）. Analysis of gene sequences of 17 RTs revealed that none of them contained stop codons and/or indels disrupting the reading frame. These different stress-origin transcriptionally active RTs were remarkably similar to each other- FATEXP2-8 and FATEYS9-7 showed 100% sequence identity. Analysis of pylogenetic of these transcriptionally active RTs and the RT sequences from genome showed that there were close phylogenetic relationships of most of the transcriptionally active RTs. The results of this study have contributed to the background information necessary for future studies for evaluating the relationship between retrotransposons and somaclonal variation.
基金supported by National Natural Science Foundation of China (No.10505018)Natural Science Foundation of Henan Province (No.511030400)
文摘Retrotransposon-like elements are major constituents of most eukaryotic genomes. For example, they account for roughly 90% of the wheat （Triticum aestivum） genome, Previous study on a wheat strain treated by low-energy N^＋ ions indicated the variations in AFLP （Amplified Fragment Length Polymorphism ） markers, One such variation was caused by the re-activation of Tyl-copia-like retrotransposons, implying that the mutagenic effects of lowenergy ions might work through elevated activation of retrotransposons, In this paper an expression profile of Tyl-copia-like retrotransposons in wheat treated by low-energy N^＋ ions is reported, The reverse transcriptase （RT） domains of these retrotransposons were amplified by reverse-transcriptional polymerase chain reaction （RT-PCR） and sequentially cloned, 42 and 65 clones were obtained from the treated （CL） and control materials （CK）, respectively, Sequence analysis of each clone was performed by software. Phylogeny and classification were calculated responding to the sequences of the RT domains. All the results show that there is much difference in the RT domain between the control sample and the treated sample, Especially, the RT domains from the treated group encode significantly more functional ORF （open reading frames） than those from the control sample, This observation suggests that the treated sample has higher activation of retrotransposons, possibly as a consequence of low-energy ion beam irradiation, It also suggests that retrotransposons in the two groups impact the host gene expression in two different ways and carry out different functions in wheat cells.
文摘Retrotransposons are present in all plant genomes and play important roles in genome size,genome structure remodeling,gene function and genome evolution.Me07Em02 marked by sequence-related amplified polymorphism (SRAP) is verified,recovered,sequenced and analyzed,which closely link to the flesh color around the stone.By comparison with the peach genome Peach v1.0,a part of the sequence of copia-like retrotransposons is obtained.With the aid of DANMAN and DNASTAR sequence analysis software,BLASTn alignment is carried out in the peach genome database and GenBank.The whole genome sequence of the copialike retrotransposon in the peach is located at 9 939 764~9 944 771 bp in Scaffold-1 of Peach v1.0,with a total length of 5 008 bp.The LTR on both sides is exactly the same,the length is 444 bp,and the largest ORF box is located at the 487~4 545 bp of the sequence,encoding 1 535 amino acids.The amino acid sequence was submitted to GenBank for Protein BLAST alignment,The results showed that this sequence also has the typical amino acid sequence characteristics of the copia-like retrotransposon.At the same time,the method of peach retrotransposon labeling is preliminarily established,and the genetic diversity of the peach is analyzed.
基金supported by National and Fujian Provincial Natural Science Foundation(No.31371557 and K55NI921A)Fujian Provincial Department of Education Project(K58MLV03A)a startup fund from Fujian Agriculture and Forestry University(http://www.fafu.edu.cn/)to X.S
文摘A novel rice d1 mutant was identified using map-based cloning and comparative analysis of known dl mutants.The mutant[d1-a) shows a mild dwarf trait,which differs only slightly from the wildtype in plant height at the tillering stage.The dl-a mutant is different from other dl mutants.We found that it was interrupted by an Osr4 long terminal repeat(LTR)-retrotransposon,which resulted in the loss of exon 7 in the mutant D1 mRNA.A paralog of the D1 gene.D1-like,was revealed.D1-like is a truncated gene that might have resulted from recombination between retrotransposons.We identified 65 Osr4LTR-retrotransposons in Nipponbare,and found more LTR variants in contrast to coding DNA sequence(CDS) in the retrotransposons.We also identified five possible regulatory motifs in LTRs which may control the expression of the retrotransposons.In addition,we predicted six putative functional Osr4 retrotransposons that contain complete CDSs and all important elements.Osr4 retrotransposons were classified into 4 groups,and this type of retrotransposon only appears to be present in monocots.Members of group 1-1,which included all putative functional retrotransposons,showed a high similarity with each other.The retrotransposons were expressed in all tissues,at especially higher levels in some leaves and seeds.These findings imply that transpositions of group 1-1 members might have occurred frequently and recently.
文摘We report the isolation of AtL1, a 249 bp non-LTR retrotransposon fragment from Arabidopsis thaliana by fingerprinting mRNAs extracted from A. thaliana plants, ecotype Columbia, in different heat stress conditions. Southern blot and PCR analysis suggested that AtL1 occurs as a single- or low-copy insert in the genome of A. thaliana ecotype Columbia. The presence of AtL1 in the genome of different Arabidopsis ecotypes was confirmed by PCR amplification and sequencing thus excluding all possible contamination. A preliminary scan of the AtL1 nucleotide sequence against the EMBL and NCBI databases revealed a high degree of similarity to a group of LINE type L1 retrotransposons of mammals and with a cDNA sequence of Artemisia annua. A phylogenetic analysis of LINE elements from animals and plants placed AtL1 and A. annua sequences in close proximity to some mammalian sequences but distant from the other plants LINE elements including those from Arabidopsis.
基金supported by National Natural Science Foundation of China(Nos.10505018,30800204)the Chinese Ministry of Agriculture(No.200803034)
文摘Mutagenesis and retrotransposons have a close relationship, but little attention has been paid yet to the activity of retrotransposons produced by physical mutagens. The variation of retrotransposon WIS 2-1A activity in wheat （Triticum aestivum L.） embryos at three different growth times （30 h, 45 h and 60 h） was investigated after they had been treated with N^＋ implantation in a vacuum of 5× 10^-2 Pa and irradiation by ^60Coγ-ray respectively. For each of the three growth times the expression of WIS 2-1A showed almost entirely a same trend of downregulation, upregulation, then downregulation, and upregulation again with the increase in dose of N^＋ implantation, but the expression appeared irregular with the increase in irradiation of ^60Coγ-ray. In conclusion, the acutely activating effect of WIS 2-1A stimulated by vacuum and high dose N^＋ implantation within a shorter incubation time may provide a convenient tool to advance the research on mutagenic breeding and function genes.
文摘In order to identify the variation and estimate the genetic diversity among the fig (Ficus carica L.) genotypes collected from Algeria and Turkey, the genetic relationships between 86 genotypes were investigated using 23 inter primer binding sites (iPBS)-retrotransposon and 16 simple sequence repeat (SSR) primers. A total of 63 polymorphic bands for the iPBS-retrotransposon markers and 25 alleles for the SSR markers were identified with an average of 2.7 and 1.6 per primer, respectively. The average value of polymorphism information content (PIC) for the iPBS markers (0.73) was higher than that for the SSR markers (0.69). Applying the neighbor-joining method to the combined iPBS-retrotransposon and SSR data, the fig genotypes were clustered into two groups. The STRUCTURE software was used to determine the population structure. Among the genotypes studied, two populations (K = 2) were identified indicating a low diversity between the Algerian and Turkish varieties. Both types of markers were able to differentiate all the fig genotypes and were efficient in discriminating the closely related genotypes. Our data also showed that as a universal marker, iPBS-retrotransposon is a useful tool for the molecular characterization of fig genotypes.
基金supported by the National Natural Science Foundation of China(32002146 and 31872977)the China Postdoctoral Science Foundation(2020M671630)+3 种基金the Jiangsu Postdoctoral Science Foundation of China(2021K221B)to Chen Caithe Jiangsu Agriculture Science and Technology Innovation Fund,China[CX(19)2016]the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe High-end Talent Support Program of Yangzhou University,China to Song Chengyi。
文摘Retrotransposons,a type of DNA fragment that can mobilize itself on genome,can generate genetic variations and develop for molecular markers based on the insertion polymorphism.Zinc finger proteins(ZNFs)are among the most abundant proteins in eukaryotic animals,and their functions are extraordinarily diverse and particularly important in gene regulation.In the current study,bioinformatic prediction was performed to screen for retrotransposon insertion polymorphisms(RIPs)in six ZNF genes(ZNF2,ZNF3,ZNF7,ZNF8,ZNF10 and ZNF12).Six RIPs in these ZNFs,including one short interspersed nuclear element(SINE)RIP in intron 1 and one long interspersed nuclear element 1(L1)RIP in intron 3 of ZNF2,one SINE RIP in 5′flanking region and one SINE RIP in intron 2 of ZNF3,one SINE RIP in 3′UTR of ZNF7 and one L1 RIP in intron 2 of ZNF12,were discovered and their presence was confirmed by PCR.The impact of the SINE RIP in the first intron of ZNF2,which is close to the core promoter of ZNF2,on the gene activity was investigated by dual-luciferase assay in three cell lines.Our results showed that the SINE insertion in the intron 1 of ZNF2 repressed the core promoter activity extremely significantly(P<0.01)in cervical cancer cells and porcine primary embryonic fibroblasts(HeLa and PEF),thus SINE may act as a repressor.This SINE RIP also significantly(P<0.05)affected the corrected back fat thickness in Yorkshire pigs.The corrected back fat thickness of individuals with SINE insertion in the first intron of ZNF2 was significantly(P<0.05)higher than that of individuals without SINE insertion.In summary,our data suggested that RIPs play important roles in the genetic variations of these ZNF genes and SINE RIP in the intron 1 of ZNF2 may provide a useful molecular marker for the screening of fat deposition in the pig breeding.
