Molecular characterization and distribution of a 145-bp tandem repeat family in the genus Populus

Genome ◽  
1999 ◽  
Vol 42 (5) ◽  
pp. 909-918 ◽  
Author(s):  
J Rajagopal ◽  
S Das ◽  
D K Khurana ◽  
P S Srivastava ◽  
M Lakshmikumaran
Keyword(s):  
Molecular Characterization ◽  
Tandem Repeat ◽  
Tandem Repeats ◽  
Populus Deltoides ◽  
Point Mutations ◽  
Sequence Divergence ◽  
Methylation Pattern ◽  
Dot Blot ◽  
Repeat Family ◽  
Sequence Comparisons

This report aims to describe the identification and molecular characterization of a 145-bp tandem repeat family that accounts for nearly 1.5% of the Populus genome. Three members of this repeat family were cloned and sequenced from Populus deltoides and P. ciliata. The dimers of the repeat were sequenced in order to confirm the head-to-tail organization of the repeat. Hybridization-based analysis using the 145-bp tandem repeat as a probe on genomic DNA gave rise to ladder patterns which were identified to be a result of methylation and (or) sequence heterogeneity. Analysis of the methylation pattern of the repeat family using methylation-sensitive isoschizomers revealed variable methylation of the C residues and lack of methylation of the A residues. Sequence comparisons between the monomers revealed a high degree of sequence divergence that ranged between 6% and 11% in P. deltoides and between 4.2% and 8.3% in P. ciliata. This indicated the presence of sub-families within the 145-bp tandem family of repeats. Divergence was mainly due to the accumulation of point mutations and was concentrated in the central region of the repeat. The 145-bp tandem repeat family did not show significant homology to known tandem repeats from plants. A short stretch of 36 bp was found to show homology of 66.7% to a centromeric repeat from Chironomus plumosus. Dot-blot analysis and Southern hybridization data revealed the presence of the repeat family in 13 of the 14 Populus species examined. The absence of the 145-bp repeat from P. euphratica suggested that this species is relatively distant from other members of the genus, which correlates with taxonomic classifications. The widespread occurrence of the tandem family in the genus indicated that this family may be of ancient origin.Key words: Satellite DNA, centromeric DNA, genome organization, phylogeny.

Molecular characterization and distribution of a 145-bp tandem repeat family in the genus Populus

Genome ◽  
1999 ◽  
Vol 42 (5) ◽  
pp. 909-918 ◽  
Author(s):  
J. Rajagopal ◽  
S. Das ◽  
D.K. Khurana ◽  
P.S. Srivastava ◽  
M. Lakshmikumaran
Keyword(s):  
Molecular Characterization ◽  
Tandem Repeat ◽  
Repeat Family

The pericentromeric heterochromatin of the grass Zingeria biebersteiniana (2n = 4) is composed of Zbcen1-type tandem repeats that are intermingled with accumulated dispersedly organized sequences

Genome ◽  
2001 ◽  
Vol 44 (6) ◽  
pp. 955-961 ◽  
Author(s):  
Verity A Saunders ◽  
Andreas Houben
Keyword(s):  
In Situ Hybridization ◽  
Tandem Repeat ◽  
Tandem Repeats ◽  
Repetitive Sequences ◽  
Pericentromeric Region ◽  
Pericentromeric Heterochromatin ◽  
Repeat Family ◽  
Dna Reassociation ◽  
Copy Dna

DNA reassociation and hydroxyapatite chromatography were used to isolate high-copy DNA of the grass Zingeria biebersteiniana (2n = 4). In situ hybridization demonstrated that the DNA isolated was enriched for pericentromere-specific repetitive sequences. One abundant pericentromere-specific component is the differentially methylated tandem-repeat family Zbcen1. Other sequences isolated, Zb46 and Zb47A, are dispersed and display similarity to parts of the gypsy- and copia-like retrotransposable elements of other grasses. In situ hybridization with the copia-like sequence Zb47A resulted in dispersed labelling along the chromosome arms, with a significant signal accumulation in the pericentromeric region of all chromosomes. It is concluded that the pericentromeric heterochromatin of Z. biebersteiniana is composed of members of the Zbcen1 tandem repeat family and that these tandem arrays are intermingled with accumulated putative copia-like retrotransposon sequences. An observed Rabl interphase orientation suggests that the length of the chromosomes rather than the genome size is the determining factor of the Rabl phenomenon.Key Words: centromere, heterochromatin, tandemly repeated DNA, retrotransposon-like, DNA reassociation.

Structure and evolution of the Cinful retrotransposon family of maize

Genome ◽  
2003 ◽  
Vol 46 (5) ◽  
pp. 745-752 ◽  
Author(s):  
Soledad Sanz-Alferez ◽  
Phillip SanMiguel ◽  
Young-Kwan Jin ◽  
Patricia S Springer ◽  
Jeffrey L Bennetzen
Keyword(s):  
Tandem Repeats ◽  
Yeast Artificial Chromosome ◽  
Repetitive Sequences ◽  
Point Mutations ◽  
Sequence Divergence ◽  
Artificial Chromosome ◽  
Major Constituent ◽  
Apparent Lack ◽  
Gene Acquisition ◽  
Functional Components

A maize cDNA clone was isolated by virtue of its intense hybridization to total maize genomic DNA, indicating homology to highly repetitive sequences. Genomic homologues were identified and subcloned from an adh1-bearing maize yeast artificial chromosome (YAC). Sequencing revealed that the expressed sequence was part of a Ty3-gypsy-type retrotransposon. We discovered and sequenced two complete retrotransposons of this family, and named them Cinful elements because they are members of a family of maize retrotransposons including Zeon-1 and the first plant transposable element sequenced, the solo long terminal repeat (LTR) called Cin1. All are defective, as Cinful-1 and Cinful-2 elements lack gag and Zeon-1 lacks pol homology. Despite the apparent lack of an intact "autonomous" element, the Cinful family has expanded to a copy number of about 18 000, representing just under 9% of the maize genome. Both point mutations and major rearrangements, including possible gene acquisition, differentiate members of the Cinful family. Cinful family members were found to have an unusual feature that we also observed in two other Ty3-class retrotransposons of teosinte and tobacco: related tandem repeats that separate their internal domains with a gag- or pol-containing homology from a 3' segment of unknown function. The conserved and variable features identified provide insights into the origin, mutational history, and functional components of this major constituent of the maize genome.Key words: Cin1, genome evolution, sequence divergence, Ty3-gypsy elements, Zeon-1.

scholarly journals Conservation of gene architecture and domains amidst sequence divergence in thehsrωlncRNA gene across theDrosophilagenus: Anin silicoanalysis

2019 ◽  
Author(s):  
Ranjan Kumar Sahu ◽  
Eshita Mutt ◽  
Subhash Chandra Lakhotia
Keyword(s):  
Drosophila Melanogaster ◽  
Tandem Repeat ◽  
Tandem Repeats ◽  
Sequence Divergence ◽  
Splice Junction ◽  
Proximal Part ◽  
Order Structure ◽  
Repeat Region ◽  
Functional Conservation ◽  
Splice Junctions

AbstractThe developmentally active and cell-stress responsivehsrω locus inDrosophila melanogastercarries two exons, oneomegaintron, one short translatable open reading frame ORFω, long stretch of unique tandem repeats and an overlappingmir-4951near its 3’ end. It produces multiple lncRNAs using two transcription start and four termination sites. Earlier studies revealed functional conservation in severalDrosophilaspecies but with little sequence conservation, in three experimentally examined species, of ORFω, tandem repeat and other regions but ultra-conservation of 16nt at 5’ and 60nt at 3’ splice-junctions of theomegaintron. Present bioinformatic study, using the splice-junction landmarks inDrosophila melanogaster hsrω, identified orthologues in publicly available 34Drosophilaspecies genomes. Each orthologue carries the short ORFω, ultra-conserved splice junctions ofomegaintron, repeat region, conserved 3’-end locatedmir-4951, and syntenic neighbours. Multiple copies of conserved nonamer motifs are seen in the tandem repeat region, despite a high variability in repeat sequences. Intriguingly, only the intron sequences in different species show evolutionary relationships matching the general phylogenetic history in the genus. Search in other known insect genomes did not reveal sequence homology although a locus with similar functional properties is suggested inChironomusandCeratitisspecies. Amidst the high sequence divergence, the conserved organization of exons, ORFω andomegaintron in this gene’s proximal part and tandem repeats in distal part across theDrosophilagenus is remarkable and possibly reflects functional importance of higher order structure ofhsrω lncRNAs and the small Omega peptide.

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.

scholarly journals Slipped-Strand Mispairing at Noncontiguous Repeats in Poecilia reticulata: A Model for Minisatellite Birth

Genetics ◽  
2000 ◽  
Vol 155 (3) ◽  
pp. 1313-1320 ◽  
Author(s):  
John S Taylor ◽  
Felix Breden
Keyword(s):  
Tandem Repeat ◽  
Poecilia Reticulata ◽  
Tandem Repeats ◽  
Phylogenetic Reconstruction ◽  
Variable Number ◽  
Repeat Motif ◽  
Raw Material ◽  
Direct Repeats ◽  
Mt Dna ◽  
Variable Number Tandem Repeats

Abstract The standard slipped-strand mispairing (SSM) model for the formation of variable number tandem repeats (VNTRs) proposes that a few tandem repeats, produced by chance mutations, provide the “raw material” for VNTR expansion. However, this model is unlikely to explain the formation of VNTRs with long motifs (e.g., minisatellites), because the likelihood of a tandem repeat forming by chance decreases rapidly as the length of the repeat motif increases. Phylogenetic reconstruction of the birth of a mitochondrial (mt) DNA minisatellite in guppies suggests that VNTRs with long motifs can form as a consequence of SSM at noncontiguous repeats. VNTRs formed in this manner have motifs longer than the noncontiguous repeat originally formed by chance and are flanked by one unit of the original, noncontiguous repeat. SSM at noncontiguous repeats can therefore explain the birth of VNTRs with long motifs and the “imperfect” or “short direct” repeats frequently observed adjacent to both mtDNA and nuclear VNTRs.

A Centromeric Tandem Repeat Family Originating From a Part of Ty3/gypsy-Retroelement in Wheat and Its Relatives

Genetics ◽  
2003 ◽  
Vol 164 (2) ◽  
pp. 665-672 ◽  
Author(s):  
Zhi-Jun Cheng ◽  
Minoru Murata
Keyword(s):  
In Situ Hybridization ◽  
Tandem Repeats ◽  
Diploid Species ◽  
Upstream Region ◽  
Aegilops Speltoides ◽  
Repeat Family ◽  
B Genome ◽  
Intervening Sequences ◽  
Wild Diploid Species

AbstractFrom a wild diploid species that is a relative of wheat, Aegilops speltoides, a 301-bp repeat containing 16 copies of a CAA microsatellite was isolated. Southern blot and fluorescence in situ hybridization revealed that ∼250 bp of the sequence is tandemly arrayed at the centromere regions of A- and B-genome chromosomes of common wheat and rye chromosomes. Although the DNA sequence of this 250-bp repeat showed no notable homology in the databases, the flanking or intervening sequences between the repeats showed high homologies (>82%) to two separate sequences of the gag gene and its upstream region in cereba, a Ty3/gypsy-like retroelement of Hordeum vulgare. Since the amino acid sequence deduced from the 250 bp with seven CAAs showed some similarity (∼53%) to that of the gag gene, we concluded that the 250-bp repeats had also originated from the cereba-like retroelements in diploid wheat such as Ae. speltoides and had formed tandem arrays, whereas the 300-bp repeats were dispersed as a part of cereba-like retroelements. This suggests that some tandem repeats localized at the centromeric regions of cereals and other plant species originated from parts of retrotransposons.

scholarly journals Accurate measurement of microsatellite length by disrupting its tandem repeat structure

2021 ◽  
Author(s):  
Dan Levy ◽  
Zihua Wang ◽  
Andrea Moffitt ◽  
Michael H. Wigler
Keyword(s):  
Tandem Repeat ◽  
Error Rate ◽  
Tandem Repeats ◽  
Clinical Applications ◽  
Error Rates ◽  
Sequence Motifs ◽  
High Error Rate ◽  
Repeat Structure ◽  
Flanking Regions ◽  
Simple Sequence

Replication of tandem repeats of simple sequence motifs, also known as microsatellites, is error prone and variable lengths frequently occur during population expansions. Therefore, microsatellite length variations could serve as markers for cancer. However, accurate error-free quantitation of microsatellite lengths is difficult with current methods because of a high error rate during amplification and sequencing. We have solved this problem by using partial mutagenesis to disrupt enough of the repeat structure so that it can replicate faithfully, yet not so much that the flanking regions cannot be reliably identified. In this work we use bisulfite mutagenesis to convert a C to a U, later read as T. Compared to untreated templates, we achieve three orders of magnitude reduction in the error rate per round of replication. By requiring two independent first copies of an initial template, we reach error rates below one in a million. We discuss potential clinical applications of this method.

scholarly journals Comprehensive genetic diagnosis of tandem repeat expansion disorders with programmable targeted nanopore sequencing

2021 ◽  
Author(s):  
Igor Stevanovski ◽  
Sanjog R. Chintalaphani ◽  
Hasindu Gamaarachchi ◽  
James M. Ferguson ◽  
Sandy S. Pineda ◽  
...  
Keyword(s):  
Tandem Repeat ◽  
Tandem Repeats ◽  
Fragile X ◽  
Genetic Diagnosis ◽  
Neuromuscular Diseases ◽  
Nanopore Sequencing ◽  
Molecular Tests ◽  
Genetic Landscape ◽  
Long Read ◽  
Short Tandem

ABSTRACTShort-tandem repeat (STR) expansions are an important class of pathogenic genetic variants. Over forty neurological and neuromuscular diseases are caused by STR expansions, with 37 different genes implicated to date. Here we describe the use of programmable targeted long-read sequencing with Oxford Nanopore’s ReadUntil function for parallel genotyping of all known neuropathogenic STRs in a single, simple assay. Our approach enables accurate, haplotype-resolved assembly and DNA methylation profiling of expanded and non-expanded STR sites. In doing so, the assay correctly diagnoses all individuals in a cohort of patients (n = 27) with various neurogenetic diseases, including Huntington’s disease, fragile X syndrome and cerebellar ataxia (CANVAS) and others. Targeted long-read sequencing solves large and complex STR expansions that confound established molecular tests and short-read sequencing, and identifies non-canonical STR motif conformations and internal sequence interruptions. Even in our relatively small cohort, we observe a wide diversity of STR alleles of known and unknown pathogenicity, suggesting that long-read sequencing will redefine the genetic landscape of STR expansion disorders. Finally, we show how the flexible inclusion of pharmacogenomics (PGx) genes as secondary ReadUntil targets can identify clinically actionable PGx genotypes to further inform patient care, at no extra cost. Our study addresses the need for improved techniques for genetic diagnosis of STR expansion disorders and illustrates the broad utility of programmable long-read sequencing for clinical genomics.One sentence summaryThis study describes the development and validation of a programmable targeted nanopore sequencing assay for parallel genetic diagnosis of all known pathogenic short-tandem repeats (STRs) in a single, simple test.

Sign in / Sign up

Export Citation Format

Share Document