Comparative analysis of 1.688 satellite DNA on D. melanogaster species subgroup provides new insights of its pervasive presence throughout both chromatin domains and reveals a recent horizontal transfer event.

2018 ◽  
Author(s):  
Leonardo Gomes De Lima ◽  
Gustavo C. S. Kuhn
Keyword(s):  
Phylogenetic Analysis ◽  
Comparative Analysis ◽  
X Chromosome ◽  
Satellite Dna ◽  
Horizontal Transfer ◽  
Tandem Repeats ◽  
Specific Pattern ◽  
Chromosome X ◽  
Transfer Event ◽  
Species Specific

The 1.688 satellite DNA is present in the genome of Drosophila species from the melanogaster subgroup and has never been detected in species outside this subgroup. We investigated the presence and evolution of the 1.688 satDNA in all Drosophila genomes sequenced so far. Blast searches showed that 1.688 repeats are virtually confined to species from the melanogaster subgroup. Phylogenetic analysis of ~6,500 repeats extracted from D. melanogaster , D. simulans , D. sechellia , D. yakuba and D. erecta revealed the presence of 1.688 family on heterochromatin and euchromatin of all five species. Heterochromatic copies revealed a concerted mode of evolution and a species-specific pattern. Oppositely, euchromatic copies lack species-specific or array-specific pattern. Euchromatic arrays also showed a high number of insertions on 5Kb upstream/downstream of genes and in intronic regions. Unexpectedly, we found an array with at least three full 1.688 tandem repeats in the genome of D. willistoni . These repeats were highly similar to the ones present in the chromosome X of D. melanogaster , although both species have diverged from each other more than 35Mya, suggesting that 1.688 repeats from the X chromosome of D. melanogaster moved to D. willistoni by a recent horizontal transfer event.

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 Telomere-to-telomere assembly of a complete human X chromosome

2019 ◽  
Author(s):  
Karen H. Miga ◽  
Sergey Koren ◽  
Arang Rhie ◽  
Mitchell R. Vollger ◽  
Ariel Gershman ◽  
...  
Keyword(s):  
Human Genome ◽  
X Chromosome ◽  
Satellite Dna ◽  
Tandem Repeats ◽  
Reference Genome ◽  
De Novo ◽  
Hydatidiform Mole ◽  
Segmental Duplications ◽  
High Coverage ◽  
Current Reference

After nearly two decades of improvements, the current human reference genome (GRCh38) is the most accurate and complete vertebrate genome ever produced. However, no one chromosome has been finished end to end, and hundreds of unresolved gaps persist 1,2. The remaining gaps include ribosomal rDNA arrays, large near-identical segmental duplications, and satellite DNA arrays. These regions harbor largely unexplored variation of unknown consequence, and their absence from the current reference genome can lead to experimental artifacts and hide true variants when re-sequencing additional human genomes. Here we present a de novo human genome assembly that surpasses the continuity of GRCh38 2, along with the first gapless, telomere-to-telomere assembly of a human chromosome. This was enabled by high-coverage, ultra-long-read nanopore sequencing of the complete hydatidiform mole CHM13 genome, combined with complementary technologies for quality improvement and validation. Focusing our efforts on the human X chromosome 3, we reconstructed the ∼2.8 megabase centromeric satellite DNA array and closed all 29 remaining gaps in the current reference, including new sequence from the human pseudoautosomal regions and cancer-testis ampliconic gene families (CT-X and GAGE). This complete chromosome X, combined with the ultra-long nanopore data, also allowed us to map methylation patterns across complex tandem repeats and satellite arrays for the first time. These results demonstrate that finishing the human genome is now within reach and will enable ongoing efforts to complete the remaining human chromosomes.

scholarly journals Satellite DNA fromXenopus laevis: comparative analysis of 745 and 1037 base pairHindIII tandem repeats

1983 ◽  
Vol 11 (20) ◽  
pp. 6997-7009 ◽  
Author(s):  
Wolfgang Meyerhof ◽  
Beatrix Tappeser ◽  
Elke Korge ◽  
Walter Knöchel
Keyword(s):  
Comparative Analysis ◽  
Satellite Dna ◽  
Tandem Repeats

Self-amplification of satellite DNA in vitro

Genome ◽  
1998 ◽  
Vol 41 (3) ◽  
pp. 429-434 ◽  
Author(s):  
J B Buntjer ◽  
J A Lenstra
Keyword(s):  
Tandem Repeat ◽  
Satellite Dna ◽  
Genomic Dna ◽  
Tandem Repeats ◽  
Repeat Unit ◽  
Dna Amplification ◽  
Repeat Units ◽  
Rapid Amplification ◽  
Species Specific

We describe a PCR-like reaction in which genomic DNA acts as a template as well as a primer. Interaction between genomic tandem repeat units leads to self-amplification of satellite DNA. This genomic self-priming PCR (GSP-PCR) allowed the rapid amplification of species-specific tandem repeats of horse, cattle, dolphin, and chicken. A novel specific satellite of ostrich with a repeat unit of 60 bp was isolated using this method.Key words: satellite DNA, amplification, isolation, species-specific probes.

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.

scholarly journals The pangenome of the fungal pathogen Neonectria neomacrospora

2021 ◽  
Author(s):  
Knud Nor Nielsen ◽  
Kimmo Sirén ◽  
Bent Petersen ◽  
Thomas Sicheritz-Pontén ◽  
M. Thomas P. Gilbert ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Genome Size ◽  
Plant Cell Wall ◽  
Reference Genome ◽  
Nuclear Genome ◽  
Pathogenic Fungi ◽  
Specific Pattern ◽  
Eastern Canada ◽  
Repeat Content ◽  
Species Specific

ABSTRACTThe fungal plant pathogen Neonectria neomacrospora (C. Booth & Samuels) Mantiri & Samuels (Ascomycota, Hypocreales) is a bark parasite causing twig blight, canker, and in severe cases, dieback in fir (Abies spp.). Although often described as a mild pathogen, foresty and phytosanitary agencies have expressed their concern for potential economic impact. Two epidemics caused by this species are known: one from eastern Canada and one current within Northern Europe. We present key genome features of N. neomacrospora, to facilitate the research into the biology of this pathogen.We present the first genome assembly of N. neomacrospora as well as the first pangenome within this genus. The reference genome for N. neomacrospora is a long-read sequenced Danish isolate, while the pangenome is pieced together using additional 60 short-read sequenced strains covering the known geographical distribution of the species, including Europe, North America, and China.The gapless reference genome consist of twelve chromosomes sequenced telomere to telomere to a total length of 37.1 Mb. The mitochondrial genome was assembled and circularised with a length of 22 Kb.The gapless nuclear genome contains a total of 11,291 annotated genes, where 642 only have a hypothetical function, and a 4.3 % repeat content. Two minor chromosomes are enriched in transposable elements, AT content, and effector candidates. Chromosome 12 segregates within the population, indicating an accessory nature. The pangenome compile 15,101 genes, 34% more genes than present in the single isolate reference genome of N. neomacrospora. These genes organise into 13,069 homologous clusters, of which 8,316 clusters are present in all analysed strains, 985 are private to single strains.The British Columbian population branched out before the other populations and are characterized by comparatively larger genomes. The increased genome size can be explained by an expansion of repetitive elements.The comparative analysis finds a higher number of genes with a signal peptide within N. neomacrospora and species within the genus compared to the closely related genera. A species-specific pattern is observed in the carbohydrate-active enzyme repertoire, with a reduced number of polysaccharide lyases, compared to other species within the genus. The CAZymes battery responsible for plant cell wall degradation is similar to that observed in necrotrophic and hemibiotrophic plant pathogenic fungi.The genome size of N. neomacrospora is close to the median size for Ascomycota but is the smallest genome within the Neonectria genus. Comparative analysis revealed significant intraspecies genome size differences between populations explained by a difference in repeat content. Isolates with the smallest genomes formed a monophyletic group consisting of all strains from Europe and Quebec. Based on the field observations, we assume that N. neomacrospora is a hemibiotroph. Our analysis revealed a secretome consistent with a hemibiotrophic lifestyle.

X-linked CNV and skewed X-chromosome inactivation

2020 ◽  
pp. 19-21
Author(s):  
Е.А. Фонова ◽  
Е.Н. Толмачева ◽  
А.А. Кашеварова ◽  
М.Е. Лопаткина ◽  
К.А. Павлова ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Intellectual Disability ◽  
X Chromosome ◽  
Copy Number ◽  
Copy Number Variations ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation ◽  
Chromosome X ◽  
Skewed X Chromosome Inactivation

Смещение инактивации Х-хромосомы может быть следствием и маркером нарушения клеточной пролиферации при вариациях числа копий ДНК на Х-хромосоме. Х-сцепленные CNV выявляются как у женщин с невынашиванием беременности и смещением инактивации Х-хромосомы (с частотой 33,3%), так и у пациентов с умственной отсталостью и смещением инактивацией у их матерей (с частотой 40%). A skewed X-chromosome inactivation can be a consequence and a marker of impaired cell proliferation in the presence of copy number variations (CNV) on the X chromosome. X-linked CNVs are detected in women with miscarriages and a skewed X-chromosome inactivation (with a frequency of 33.3%), as well as in patients with intellectual disability and skewed X-chromosome inactivation in their mothers (with a frequency of 40%).

scholarly journals Detectable chromosome X mosaicism in males is rarely tolerated in peripheral leukocytes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Weiyin Zhou ◽  
Shu-Hong Lin ◽  
Sairah M. Khan ◽  
Meredith Yeager ◽  
Stephen J. Chanock ◽  
...  
Keyword(s):  
X Chromosome ◽  
Gene Dosage ◽  
Large Population ◽  
Population Based ◽  
Chromosome X ◽  
Genotyping Array ◽  
Chromosome Mosaicism ◽  
Age Related ◽  
Leukocyte Function ◽  
Peripheral Leukocytes

AbstractAge-related male Y and female X chromosome mosaicism is commonly observed in large population-based studies. To investigate the frequency of male X chromosome mosaicism, we scanned for deviations in chromosome X genotyping array intensity data in a population-based survey of 196,219 UK Biobank men. We detected 12 (0.006%) men with mosaic chromosome X gains ≥ 2 Mb and found no evidence for mosaic chromosome X loss, a level of detection substantially lower than for autosomes or other sex chromosomes. The rarity of chromosome X mosaicism in males relative to females reflects the importance of chromosome X gene dosage for leukocyte function.

LINE-1 distribution in six rodent genomes follow a species-specific pattern

2016 ◽  
Vol 95 (1) ◽  
pp. 21-33 ◽  
Author(s):  
A. VIEIRA-DA-SILVA ◽  
F. ADEGA ◽  
H. GUEDES-PINTO ◽  
R. CHAVES
Keyword(s):  
Specific Pattern ◽  
Species Specific

scholarly journals Lack of satellite DNA species-specific homogenization and relationship to chromosomal rearrangements in monitor lizards (Varanidae, Squamata)

2017 ◽  
Vol 17 (1) ◽  
Author(s):  
Ornjira Prakhongcheep ◽  
Watcharaporn Thapana ◽  
Aorarat Suntronpong ◽  
Worapong Singchat ◽  
Khampee Pattanatanang ◽  
...  
Keyword(s):  
Satellite Dna ◽  
Chromosomal Rearrangements ◽  
Monitor Lizards ◽  
Species Specific
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