scholarly journals Differentially Amplified Repetitive Sequences Among Aegilops tauschii Subspecies and Genotypes

2021 ◽  
Vol 12 ◽  
Author(s):  
Rahman Ebrahimzadegan ◽  
Fatemeh Orooji ◽  
Pengtao Ma ◽  
Ghader Mirzaghaderi
Keyword(s):  
Dna Sequences ◽  
Tandem Repeats ◽  
Repetitive Sequences ◽  
Aegilops Tauschii ◽  
Distribution Patterns ◽  
Snp Analysis ◽  
Specific Sequence ◽  
Factors Affecting ◽  
Illumina Sequence ◽  
Species Specific

Genomic repetitive sequences commonly show species-specific sequence type, abundance, and distribution patterns, however, their intraspecific characteristics have been poorly described. We quantified the genomic repetitive sequences and performed single nucleotide polymorphism (SNP) analysis between 29 Ae. tauschii genotypes and subspecies using publicly available raw genomic Illumina sequence reads and used fluorescence in situ hybridization (FISH) to experimentally analyze some repeats. The majority of the identified repetitive sequences had similar contents and proportions between anathera, meyeri, and strangulata subspecies. However, two Ty3/gypsy retrotransposons (CL62 and CL87) showed significantly higher abundances, and CL1, CL119, CL213, CL217 tandem repeats, and CL142 retrotransposon (Ty1/copia type) showed significantly lower abundances in subspecies strangulata compared with the subspecies anathera and meyeri. One tandem repeat and 45S ribosomal DNA (45S rDNA) abundances showed a high variation between genotypes but their abundances were not subspecies specific. Phylogenetic analysis using the repeat abundances of the aforementioned clusters placed the strangulata subsp. in a distinct clade but could not discriminate anathera and meyeri. A near complete differentiation of anathera and strangulata subspecies was observed using SNP analysis; however, var. meyeri showed higher genetic diversity. FISH using major tandem repeats couldn’t detect differences between subspecies, although (GAA)10 signal patterns generated two different karyotype groups. Taken together, the different classes of repetitive DNA sequences have differentially accumulated between strangulata and the other two subspecies of Ae. tauschii that is generally in agreement with spike morphology, implying that factors affecting repeatome evolution are variable even among highly closely related lineages.

PCR-BASED SYNTHESIS OF REPETITIVE SINGLE-STRANDED DNA FOR APPLICATIONS TO NANOBIOTECHNOLOGY

2005 ◽  
Vol 04 (03) ◽  
pp. 287-294
Author(s):  
SIMA S. ZEIN ◽  
ALEXANDRE A. VETCHER ◽  
STEPHEN D. LEVENE
Keyword(s):  
Dna Sequences ◽  
Tandem Repeats ◽  
Repetitive Sequences ◽  
Practical Interest ◽  
Telomeric Sequence ◽  
Automated Synthesis ◽  
Dna Molecules ◽  
Specific Sequence ◽  
Single Stranded Dna ◽  
Pcr Method

Recent data show that assembly of repetitive-sequence, single-stranded DNA molecules (ssDNA) and carbon nanotubes (CNTs) depend on the specific sequence repeat. Therefore, it is of practical interest to assess various methods for generating single-stranded DNA molecules that contain repetitive sequences. Existing automated synthesis procedures for generating long (> 100 nt) ssDNA molecules generate ssDNA products of variable purity and yield. An alternative to automated synthesis is the polymerase chain reaction (PCR), which provides a powerful tool for the amplification of minute amounts of specific DNA sequences. Here we show that a modified asymmetric PCR method allows synthesis of long ssDNAs comprised of tandem repeats of the repetitive vertebrate telomeric sequence (TTAGGG)n, and is also applicable to arbitrary (repetitive or nonrepetitive) DNA. Long, repetitive deoxynucleotides produced by automated synthesis are surprisingly heterogeneous with respect to both length and sequence. Benefits of the method described here are that long, repetitive ssDNA sequences are generated with high sequence fidelity and yield.

scholarly journals Sequence, Chromatin and Evolution of Satellite DNA

2021 ◽  
Vol 22 (9) ◽  
pp. 4309
Author(s):  
Jitendra Thakur ◽  
Jenika Packiaraj ◽  
Steven Henikoff
Keyword(s):  
Dna Sequences ◽  
Satellite Dna ◽  
Tandem Repeats ◽  
Large Fraction ◽  
Dna Curvature ◽  
Sequence Motifs ◽  
Specific Sequence ◽  
Satellite Dnas ◽  
Dna Repeat ◽  
Species Specific

Satellite DNA consists of abundant tandem repeats that play important roles in cellular processes, including chromosome segregation, genome organization and chromosome end protection. Most satellite DNA repeat units are either of nucleosomal length or 5–10 bp long and occupy centromeric, pericentromeric or telomeric regions. Due to high repetitiveness, satellite DNA sequences have largely been absent from genome assemblies. Although few conserved satellite-specific sequence motifs have been identified, DNA curvature, dyad symmetries and inverted repeats are features of various satellite DNAs in several organisms. Satellite DNA sequences are either embedded in highly compact gene-poor heterochromatin or specialized chromatin that is distinct from euchromatin. Nevertheless, some satellite DNAs are transcribed into non-coding RNAs that may play important roles in satellite DNA function. Intriguingly, satellite DNAs are among the most rapidly evolving genomic elements, such that a large fraction is species-specific in most organisms. Here we describe the different classes of satellite DNA sequences, their satellite-specific chromatin features, and how these features may contribute to satellite DNA biology and evolution. We also discuss how the evolution of functional satellite DNA classes may contribute to speciation in plants and animals.

A species-specific satellite DNA from the entomopathogenic nematode Heterorhabditis indicus

Genome ◽  
1998 ◽  
Vol 41 (2) ◽  
pp. 148-153 ◽  
Author(s):  
Monique Abadon ◽  
Eric Grenier ◽  
Christian Laumond ◽  
Pierre Abad
Keyword(s):  
Dna Sequence ◽  
Satellite Dna ◽  
Tandem Repeats ◽  
Sequence Data ◽  
Entomopathogenic Nematode ◽  
Consensus Sequence ◽  
Repeated Sequence ◽  
Nucleotide Sequence Analysis ◽  
Specific Sequence ◽  
Species Specific

An AluI satellite DNA family has been cloned from the entomopathogenic nematode Heterorhabditis indicus. This repeated sequence appears to be an unusually abundant satellite DNA, since it constitutes about 45% of the H. indicus genome. The consensus sequence is 174 nucleotides long and has an A + T content of 56%, with the presence of direct and inverted repeat clusters. DNA sequence data reveal that monomers are quite homogeneous. Such homogeneity suggests that some mechanism is acting to maintain the homogeneity of this satellite DNA, despite its abundance, or that this repeated sequence could have appeared recently in the genome of H. indicus. Hybridization analysis of genomic DNAs from different Heterorhabditis species shows that this satellite DNA sequence is specific to the H. indicus genome. Considering the species specificity and the high copy number of this AluI satellite DNA sequence, it could provide a rapid and powerful tool for identifying H. indicus strains.Key words: AluI repeated DNA, tandem repeats, species-specific sequence, nucleotide sequence analysis.

scholarly journals Efficient anchoring of Erianthus arundinaceus chromatin introgressed into sugarcane by specific molecular markers

2020 ◽  
Author(s):  
Yongji Huang ◽  
Jiayun Wu ◽  
Xueting Li ◽  
Fan Yu ◽  
Xuguang Hu ◽  
...  
Keyword(s):  
Molecular Markers ◽  
High Throughput ◽  
Repetitive Sequence ◽  
Repetitive Sequences ◽  
Distribution Patterns ◽  
Subtractive Hybridization ◽  
High Accuracy ◽  
Wild Relatives ◽  
45S Rdna ◽  
Species Specific

Abstract Background: Erianthus arundinaceus is a valuable gene reservoir for sugarcane improvement. However, insufficient molecular markers for high-accuracy identification and tracking of the introgression status of E. arundinaceus chromatin impede sugarcane breeding. Fortunately, suppression subtractive hybridization (SSH) technology provides an excellent opportunity for development of high-throughput E. arundinaceus-specific molecular markers at a reasonable cost. Results: In this study, we constructed a SSH library of E. arundinaceus. In total, 288 clones E. arundinaceus-specific repetitive sequences were screened out and their distribution patterns on chromosomes were characterized by fluorescence in situ hybridization (FISH). A subtelomeric repetitive sequence Ea086 and a diffusive repetitive sequence Ea009, plus 45S rDNA-bearing E. arundinaceus chromosome repetitive sequence EaITS were developed as E. arundinaceus-specific molecular markers, namely Ea086-128, Ea009-257, and EaITS-278, covering all the E. arundinaceus chromosomes for high-accuracy identification of putative progeny. Both Ea086-128 and Ea009-257 were successfully applied to identify the authenticity of F1, BC1, BC2, BC3, and BC4 progeny between sugarcane and E. arundinaceus. In addition, EaITS-278 was a 45S rDNA-bearing E. arundinaceus chromosome-specific molecular marker for rapid tracking the inherited status of this chromosome in sugarcane background. Three BC3 progeny had apparently lost the 45S rDNA-bearing E. arundinaceus chromosome. Conclusions: We reported herein a highly effective and reliable SSH-based technology for discovery of high-throughput E. arundinaceus-specific sequences bearing high potential as molecular markers. Given its reliability and savings in time and efforts, the method is also suitable for development of species-specific molecular markers for other important wild relatives to accelerate introgression of wild relatives into sugarcane.

Oligonucleotide fingerprinting reveals various probe-dependent levels of informativeness in chickpea (Cicer arietinum)

Genome ◽  
1992 ◽  
Vol 35 (3) ◽  
pp. 436-442 ◽  
Author(s):  
Kurt Weising ◽  
Dieter Kaemmer ◽  
Franz Weigand ◽  
Jörg T. Epplen ◽  
Gunter Kahl
Keyword(s):  
Cicer Arietinum ◽  
Dna Sequences ◽  
Repetitive Sequences ◽  
Banding Patterns ◽  
Simple Repetitive Sequences ◽  
Leguminous Crop ◽  
Oligonucleotide Fingerprinting ◽  
Species Specific ◽  
Synthetic Oligonucleotides ◽  
Different Levels

Synthetic oligonucleotides complementary to simple repetitive DNA sequences were used to detect inter- and intra-specific polymorphisms in a leguminous crop plant (chickpea, Cicer arietinum) and its wild relatives. All the investigated repetitive motifs [(GACA)4, (GATA)4, (GTG)5, (CA)8, (TCC)5, (GGAT)4, and (AGTTT)4] were abundantly present and polymorphic in the chickpea genome. Different probes revealed different levels of variability. Whereas species-specific banding patterns were obtained with the (GTG)5 probe, other probes revealed differences between accessions, or even individuals. The somatic multilocus patterns were stable for all probes.Key words: genetic polymorphism, simple repetitive sequences, DNA fingerprinting, synthetic oligonucleotide probes.

scholarly journals DiviSSR: Simple arithmetic for efficient identification of tandem repeats

2021 ◽  
Author(s):  
Akshay Kumar Avvaru ◽  
Rakesh K Mishra ◽  
Divya Tej Sowpati
Keyword(s):  
Dna Sequences ◽  
Tandem Repeats ◽  
Mathematical Structure ◽  
Mathematical Methods ◽  
Accurate Identification ◽  
Simple Arithmetic ◽  
Specific Sequence ◽  
Mathematical Properties ◽  
Vector Representations ◽  
Sequence Characteristics

Numerical or vector representations of DNA sequences have been applied for identification of specific sequence characteristics and patterns which are not evident in their character (A, C, G, T) representations. These transformations often reveal a mathematical structure to the sequences which can be captured efficiently using established mathematical methods. One such transformation, the 2-bit format, represents each nucleotide using only two bits instead of eight for efficient storage of genomic data. Here we describe a mathematical property that exists in the 2-bit representation of tandemly repeated DNA sequences. Our tool, DiviSSR (pronounced divisor), leverages this property and subsequent arithmetic for ultrafast and accurate identification of tandem repeats. DiviSSR can process the entire human genome in ~30s, and short sequence reads at a rate of >1 million reads/s on a single CPU thread. Our work also highlights the implications of using simple mathematical properties of DNA sequences for faster algorithms in genomics.

A novel species-specific tandem repeat DNA family from Sinapis arvensis: detection of telomere-like sequences

Genome ◽  
1996 ◽  
Vol 39 (4) ◽  
pp. 758-766 ◽  
Author(s):  
Ritu Kapila ◽  
Sandip Das ◽  
Malathi Lakshmikumaran ◽  
P. S. Srivastava
Keyword(s):  
Tandem Repeat ◽  
Dna Sequences ◽  
Tandem Repeats ◽  
Consensus Sequence ◽  
Repeat Element ◽  
Matrix Analysis ◽  
Repetitive Region ◽  
Repeat Family ◽  
Sinapis Arvensis ◽  
Species Specific

DNA sequences representing a tandemly repeated DNA family of the Sinapis arvensis genome were cloned and characterized. The 700-bp tandem repeat family is represented by two clones, pSA35 and pSA52, which are 697 and 709 bp in length, respectively. Dot matrix analysis of the sequences indicates the presence of repeated elements within each monomeric unit. Sequence analysis of the repetitive region of clones pSA35 and pSA52 shows that there are several copies of a 7-bp repeat element organized in tandem. The consensus sequence of this repeat element is 5′-TTTAGGG-3′. These elements are highly mutated and the difference in length between the two clones is due to different copy numbers of these elements. The repetitive region of clone pSA35 has 26 copies of the element TTTAGGG, whereas clone pSA52 has 28 copies. The repetitive region in both clones is flanked on either side by inverted repeats that may be footprints of a transposition event. Sequence comparison indicates that the element TTTAGGG is identical to telomeric repeats present in Arabidopsis, maize, tomato, and other plants. However, Bal31digestion kinetics indicates non-telomeric localization of the 700-bp tandem repeats. The clones represent a novel repeat family as (i) they contain telomere-like motifs as subrepeats within each unit; and (ii) they do not hybridize to related crucifers and are species-specific in nature. Key words : Brassica species, Sinapis arvensis, tandem repeats, telomeres.

Cloning and characterization of the majority of repetitive DNA in cotton (Gossypium L.)

Genome ◽  
1995 ◽  
Vol 38 (6) ◽  
pp. 1177-1188 ◽  
Author(s):  
Xinping Zhao ◽  
Rod A. Wing ◽  
Andrew H. Paterson
Keyword(s):  
Repetitive Dna ◽  
Dna Sequences ◽  
Tandem Repeats ◽  
Repetitive Sequences ◽  
Repetitive Dna Sequences ◽  
Tetraploid Cotton ◽  
Cotton Genome ◽  
Cotton Species ◽  
Dna Elements ◽  
Repetitive Dna Elements

Repetitive DNA elements representing 60–70% of the total repetitive DNA in tetraploid cotton (Gossypium barbadense L.) and comprising 30–36% of the tetraploid cotton genome were isolated from a genomic library of DNA digested with a mixture of four blunt-end cutting restriction enzymes. A total of 313 clones putatively containing nuclear repetitive sequences were classified into 103 families, based on cross hybridization and Southern blot analysis. The 103 families were characterized in terms of genome organization, methylation pattern, abundance, and DNA variation. As in many other eukaryotic genomes, interspersed repetitive elements are the most abundant class of repetitive DNA in the cotton genome. Paucity of tandem repeat families with high copy numbers (>104) may be a unique feature of the cotton genome as compared with other higher plant genomes. Interspersed repeats tend to be methylated, while tandem repeats seem to be largely unmethylated in the cotton genome. Minimal variation in repertoire and overall copy number of repetitive DNA elements among different tetraploid cotton species is consistent with the hypothesis of a relatively recent origin of tetraploid cottons.Key words: genome analysis, genome evolution, tandemly repetitive DNA sequences, interspersed repetitive DNA sequences, polyploid.

scholarly journals Codon harmonization reduces amino acid misincorporation in bacterially expressed P. falciparum proteins and improves their immunogenicity

AMB Express ◽  
2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Neeraja Punde ◽  
Jennifer Kooken ◽  
Dagmar Leary ◽  
Patricia M. Legler ◽  
Evelina Angov
Keyword(s):  
Protein Structure ◽  
Amino Acid ◽  
Codon Usage ◽  
Dna Sequences ◽  
Structural Integrity ◽  
Host Cells ◽  
Loss Of Function ◽  
Species Specific ◽  
And Function ◽  
The Impact

Abstract Codon usage frequency influences protein structure and function. The frequency with which codons are used potentially impacts primary, secondary and tertiary protein structure. Poor expression, loss of function, insolubility, or truncation can result from species-specific differences in codon usage. “Codon harmonization” more closely aligns native codon usage frequencies with those of the expression host particularly within putative inter-domain segments where slower rates of translation may play a role in protein folding. Heterologous expression of Plasmodium falciparum genes in Escherichia coli has been a challenge due to their AT-rich codon bias and the highly repetitive DNA sequences. Here, codon harmonization was applied to the malarial antigen, CelTOS (Cell-traversal protein for ookinetes and sporozoites). CelTOS is a highly conserved P. falciparum protein involved in cellular traversal through mosquito and vertebrate host cells. It reversibly refolds after thermal denaturation making it a desirable malarial vaccine candidate. Protein expressed in E. coli from a codon harmonized sequence of P. falciparum CelTOS (CH-PfCelTOS) was compared with protein expressed from the native codon sequence (N-PfCelTOS) to assess the impact of codon usage on protein expression levels, solubility, yield, stability, structural integrity, recognition with CelTOS-specific mAbs and immunogenicity in mice. While the translated proteins were expected to be identical, the translated products produced from the codon-harmonized sequence differed in helical content and showed a smaller distribution of polypeptides in mass spectra indicating lower heterogeneity of the codon harmonized version and fewer amino acid misincorporations. Substitutions of hydrophobic-to-hydrophobic amino acid were observed more commonly than any other. CH-PfCelTOS induced significantly higher antibody levels compared with N-PfCelTOS; however, no significant differences in either IFN-γ or IL-4 cellular responses were detected between the two antigens.

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