scholarly journals Isolation and characterization of Ty1-copia retrotransposons in Saccharum officinarum

Author(s):  
Ke Chen ◽  
Fan Yu ◽  
Yongji Huang ◽  
Xianglin Wu ◽  
Shan Yang ◽  
...  

Background. Saccharum officinarum is the most significant resource for sugar and high-yield genes in sugarcane breeding programs. However, the unknown information of evolution and genome organization remain largely in the sugarcane, which has limited progress in sugarcane breeding. Retrotransposons occupy a large proportion of the plant genome; therefore, characterization of Ty1-copia retrotransposons will improve understanding of the evolution and organization of plant genomes. Methods. The present study isolated conserved domains of Ty1-copia retrotransposon-encoded reverse transcriptase genes from S. officinarum to characterize their phylogenetic diversity, genomic abundance, and chromosomal distribution. Results. In total, 42 Ty1-copia reverse transcriptase sequences with 35-100% similarity and high levels of heterogeneity were obtained. Of them, 11 (26%) were disrupted by stop codons and/or frameshift mutations. Phylogenetic analysis revealed these sequences could be split into four distinct evolutionary lineages (Tork/TAR, Tork/Angela, Sire/Maximus, and Retrofit/Ale). Dot blot analysis showed that Ty1-copia retrotransposons represent a significant portion of the S. officinarum genome, with copy numbers as high as 1.7 × 105. Fluorescence in situ hybridization revealed that Ty1-copia retrotransposons were dispersed within heterochromatic regions among all S. officinarum chromosomes, with around 30 obvious signals clustering in terminal regions. However, Ty1-copia retrotransposons were not found in nucleolar organizing regions of 45S rDNA. Discussion. These results serve to enhance our understanding of the chromosomal distribution and evolution of the S. officinarum genome as well as promote possible utilization of retrotransposons in sugarcane breeding programs.

2018 ◽  
Author(s):  
Ke Chen ◽  
Fan Yu ◽  
Yongji Huang ◽  
Xianglin Wu ◽  
Shan Yang ◽  
...  

Background. Saccharum officinarum is the most significant resource for sugar and high-yield genes in sugarcane breeding programs. However, the unknown information of evolution and genome organization remain largely in the sugarcane, which has limited progress in sugarcane breeding. Retrotransposons occupy a large proportion of the plant genome; therefore, characterization of Ty1-copia retrotransposons will improve understanding of the evolution and organization of plant genomes. Methods. The present study isolated conserved domains of Ty1-copia retrotransposon-encoded reverse transcriptase genes from S. officinarum to characterize their phylogenetic diversity, genomic abundance, and chromosomal distribution. Results. In total, 42 Ty1-copia reverse transcriptase sequences with 35-100% similarity and high levels of heterogeneity were obtained. Of them, 11 (26%) were disrupted by stop codons and/or frameshift mutations. Phylogenetic analysis revealed these sequences could be split into four distinct evolutionary lineages (Tork/TAR, Tork/Angela, Sire/Maximus, and Retrofit/Ale). Dot blot analysis showed that Ty1-copia retrotransposons represent a significant portion of the S. officinarum genome, with copy numbers as high as 1.7 × 105. Fluorescence in situ hybridization revealed that Ty1-copia retrotransposons were dispersed within heterochromatic regions among all S. officinarum chromosomes, with around 30 obvious signals clustering in terminal regions. However, Ty1-copia retrotransposons were not found in nucleolar organizing regions of 45S rDNA. Discussion. These results serve to enhance our understanding of the chromosomal distribution and evolution of the S. officinarum genome as well as promote possible utilization of retrotransposons in sugarcane breeding programs.


1994 ◽  
Vol 59 (7) ◽  
pp. 1584-1595 ◽  
Author(s):  
Tomáš Jelínek ◽  
Josef Holub ◽  
Bohumil Štíbr ◽  
Xavier L. R. Fontaine ◽  
John D. Kennedy

Deprotonation of neutral arachno-4,5-C2B7H13 (1) either with 1, 8-(NMe2)2C10H6 (proton sponge, PS) or with a mixture of aqueous K2CO3 and [NMe4]Cl leads to the isolation in high yield of the [arachno-4,5-C2B7H12]- anion (2). Isostructural with this anion is the ligand derivative exo-6-(MeNC)-arachno-4,5-C2B7H11 (3), which is prepared in 20% yield from the reaction between arachno-4,5-C2B7H13 and MeNC in dichloromethane. Under comparable conditions compound 1 with tertiary amines gives the first representatives of the nine-vertex hypho family of dicarbaboranes, the ligand derivatives exo-5-(NR3)-hypho-4,9-C2B7H13 (4a and 4b, where R = Me and Et, respectively) in moderate yields (20 - 55%), whereas the reaction between 1 and aqueous NaCN results in the selective removal of one boron vertex to yield the eight-vertex [hypho-7,8-C2B6H13]- anion (5) in 61% yield. All compounds isolated were characterized by 11B and 1H NMR spectroscopy, with two-dimensional and selective decoupling techniques giving unambiguous assignments.


1971 ◽  
Vol 34 (3) ◽  
pp. 301-309 ◽  
Author(s):  
Wolff M. Kirsch ◽  
Demoy Schulz ◽  
Paul Nakane ◽  
Robert Lasher ◽  
Tadami Yamamoto

✓ Intact lyophilized nuclei and chromosomes were obtained from glioblastomas or brain, either in situ or in culture, by freezing at −156°C, drying at −25°C, and mechanical disassociation in glycerol at 2°C. Nuclear or chromosomal isolation was accomplished in hygroscopic nonaqueous media of high density. The method gave homogeneous nuclear and chromosomal preparations in high yield with preservation of labile, water-soluble constituents and residual biosynthetic activity. Unique opportunities for quantitative cytochemical studies at the level of the subcellular organelle are made available by the method.


1975 ◽  
Vol 58 (1) ◽  
pp. 6-9
Author(s):  
Francis I Onuska ◽  
Michael E Comba

Abstract Ultraviolet irradiation of cis- and trares-chlordane yielded 3 photolysis products. The expected half-caged analog of cis-chlordane was formed in high yield, and 2 minor photoproducts of trans-chlordane were observed. One of these products was a half-caged isomer. The individual photoproducts were isolated by thin layer chromatography and characterized by infrared, nuclear magnetic resonance, and mass spectrometry.


Genome ◽  
2010 ◽  
Vol 53 (5) ◽  
pp. 331-336 ◽  
Author(s):  
Nathalie Piperidis ◽  
Jian-wen Chen ◽  
Hai-hua Deng ◽  
Li-Ping Wang ◽  
Phillip Jackson ◽  
...  

Within Erianthus , a genus close to Saccharum , the species E. arundinaceus has the potential to contribute valuable traits to sugarcane, including adaptation to biotic and abiotic stresses and ratooning ability. Sugarcane breeders have tried for a long time to use Erianthus species in their breeding programs but until recently were constrained by a lack of fertile Saccharum × Erianthus hybrids. We report here for the first time the chromosome composition of fertile Saccharum officinarum  × E. arundinaceus F1, BC1 (F1 × sugarcane cultivar), and BC2 (BC1 × sugarcane cultivar) hybrids. The F1 and BC2 resulted from n + n chromosome transmission, while the BC1 resulted from 2n + n transmission. In the BC1 clones, the number of E. arundinaceus chromosomes ranged from 21 to 30, and in the BC2 clones, the number ranged from 14 to 15, revealing cases of chromosome loss. No recombination events between Saccharum and Erianthus chromosomes were observed in either the BC1 or BC2 clones. The implications of these results for introgression of genes from E. arundinaceus in sugarcane breeding programs are discussed. We propose a strategy to identify the agronomic value of chromosomes from E. arundinaceus and to conduct targeted breeding based on this information.


2020 ◽  
Vol 160 (5) ◽  
pp. 272-282
Author(s):  
Shan Yang ◽  
Kai Zeng ◽  
Ke Chen ◽  
Xinwang Zhao ◽  
Jiayun Wu ◽  
...  

Saccharum spontaneum is a wild germplasm resource of the genus Saccharum that has many valuable traits. Ty1-copia retrotransposons constitute a large proportion of plant genomes and affect genome sequence organization and evolution. This study aims to analyze the sequence heterogeneity, phylogenetic diversity, copy number, and chromosomal dispersion patterns of Ty1-copia retrotransposons in S. spontaneum. A total of 44 Ty1-copia reverse transcriptase subclones isolated from S. spontaneum showed a range of heterogeneity, and all sequences were A-T rich, averaging approximately 54.59%. Phylogenetic analysis divided the 44 reverse transcriptase sequences into 5 distinct lineages (Retrofit/Ale, Sire/Maximus, Bianca, Tork/TAR, and Ty1-copia like). Dot-blot hybridization revealed that Ty1-copia retrotransposons consisted of a significant component of approximately 38,900 copies and 16,300 copies per genome in the accessions YN82-114 (2n = 10x = 80) and AP85-441 (2n = 4x = 32), respectively. The results of a local blast analysis showed that there are 15,069 Ty1-copia retrotransposon copies in the genome of AP85-441, of which the Retrofit/Ale lineage had the highest copy number, followed by the Tork/TAR, Sire/Maximus, and Bianca lineages. Furthermore, both FISH and the local blast analysis with AP85-441 genomic data demonstrated that the Ty1-copia retrotransposons were unevenly distributed throughout the chromosomes. Taken together, this study provides insights into the role of Ty1-copia retrotransposons in the evolution and organization of the S. spontaneum genome.


1983 ◽  
Vol 213 (2) ◽  
pp. 485-494 ◽  
Author(s):  
P Scudder ◽  
K Uemura ◽  
J Dolby ◽  
M N Fukuda ◽  
T Feizi

Six strains of Bacteroides fragilis were examined and all found to produce endo-beta-galactosidase, an enzyme that hydrolyses internal β-galactosidic linkages of oligosaccharides belonging to the poly-N-acetyl-lactosamine series, with the common structure GlcNAc β 1 leads to 3Gal β 1 leads to 4GlcNAc/Glc. The enzyme was produced without the addition of an inducer such as keratan sulphate. It was purified 7000-fold from the culture supernatant and obtained with a yield 4-10-fold greater than from sources described previously. The specificity of the enzyme towards bovine corneal keratan sulphate, milk oligosaccharides and the glycolipids lacto-N-neotetraosylceramide and lacto-N-tetraosylceramide closely resembled that of the endo-beta-galactosidase isolated from Escherichia freundii. A novel observation was that both enzymes hydrolysed the type 2 sequence, Gal β 1 leads to 4GlcNAc β 1 leads to 3Gal β 1 leads to 4Glc, at about twice the rate of the type 1 isomer, Gal β 1 leads to 3GlcNAc β 1 leads to 3Gal β 1 leads to 4Glc. Because of the ease of purification of the enzyme and high yield in the absence of contaminating glycosidases and proteinases, Bacteroides fragilis is a valuable source of endo-beta-galactosidase for the structural analysis of carbohydrate chains.


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