Plantago lagopus B Chromosome Is Enriched in 5S rDNA-Derived Satellite DNA

2016 ◽  
Vol 148 (1) ◽  
pp. 68-73 ◽  
Author(s):  
Katrin Kumke ◽  
Jiří Macas ◽  
Jörg Fuchs ◽  
Lothar Altschmied ◽  
Jasmeet Kour ◽  
...  
Keyword(s):  
Repetitive Sequences ◽  
Nuclear Genome ◽  
5S Rdna ◽  
B Chromosome ◽  
B Chromosomes ◽  
Specific Marker ◽  
Sequencing Technology ◽  
Plantago Lagopus ◽  
Copy Dna ◽  
Chromosome Segments

B chromosomes are supernumerary dispensable parts of the karyotype which appear in some individuals of some populations in some species. Using advanced sequencing technology, we in silico characterized the high-copy DNA composition of Plantago lagopus with and without B chromosomes. The nuclear genome (2.46 pg/2C) was found to be relatively rich in repetitive sequences, with highly and moderately repeated elements making up 68% of the genome. Besides a centromere-specific marker, we identified a B-specific satellite and a repeat enriched in polymorphic A chromosome segments. The B-specific tandem repeat PLsatB originated from sequence amplification including 5S rDNA fragments.

scholarly journals Repetitive DNA landscape in essential A and supernumerary B chromosomes of Festuca pratensis Huds

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Rahman Ebrahimzadegan ◽  
Andreas Houben ◽  
Ghader Mirzaghaderi
Keyword(s):  
Repetitive Sequences ◽  
Nuclear Genome ◽  
B Chromosome ◽  
B Chromosomes ◽  
Festuca Pratensis ◽  
Ltr Retrotransposons ◽  
Chromosome Identification ◽  
Satellite Repeats ◽  
Low Pass ◽  
Illumina Sequence

AbstractHere, we characterized the basic properties of repetitive sequences in essential A and supernumerary B chromosomes of Festuca pratensis Huds. This was performed by comparative analysis of low-pass Illumina sequence reads of B chromosome lacking (−B) and B chromosome containing (+B) individuals of F. pratensis. 61% of the nuclear genome is composed of repetitive sequences. 43.1% of the genome are transposons of which DNA transposons and retrotransposons made up 2.3% and 40.8%, respectively. LTR retrotransposons are the most abundant mobile elements and contribute to 40.7% of the genome and divided into Ty3-gypsy and Ty1-copia super families with 32.97% and 7.78% of the genome, respectively. Eighteen different satellite repeats were identified making up 3.9% of the genome. Five satellite repeats were used as cytological markers for chromosome identification and genome analysis in the genus Festuca. Four satellite repeats were identified on B chromosomes among which Fp-Sat48 and Fp-Sat253 were specific to the B chromosome of F. pratensis.

B Chromosome Diversity and Repetitive Sequence Distribution in an Isolated Population of Akodon montensis (Rodentia, Sigmodontinae)

2018 ◽  
Vol 154 (2) ◽  
pp. 79-85
Author(s):  
Amanda A. Soares ◽  
Jonathan P. Castro ◽  
Pedro Balieiro ◽  
Sidnei Dornelles ◽  
Tiago M. Degrandi ◽  
...  
Keyword(s):  
Evolutionary Dynamics ◽  
Repetitive Sequences ◽  
5S Rdna ◽  
B Chromosome ◽  
B Chromosomes ◽  
Telomeric Sequences ◽  
Supernumerary Chromosomes ◽  
Dna Libraries ◽  
Eukaryotic Species ◽  
Size And Morphology

B chromosomes are supernumerary chromosomes found in the karyotypes of approximately 15% of all eukaryotic species. They present parasitic behavior and do not follow the standard Mendelian pattern of inheritance, resulting in an imbalance in gametogenesis. The evolutionary dynamics of B chromosomes is still unknown for many species, but studies indicate that the accumulation of repetitive sequences plays an important role in the differentiation of these elements. We analyzed morphology, frequency, and possible homologies amongst different B chromosomes found in an isolated Akodon montensis population in southern Brazil. Repetitive sequences (18S, 5S rDNA and telomeric sequences) were used to test for their accumulation on the supernumerary chromosomes and describe their localization in the species. The results indicate 4 different B chromosome morphotypes, and DNA libraries were generated for 3 of them. 18S rDNA was labelled polymorphically, except in the B chromosomes, whereas the 5S rDNA was located exclusively in an interstitial position on the long arm of chromosome 5. Chromosome painting with the B probes based on FISH revealed a homologous composition for all B chromosome morphotypes and no homology with the chromosomes in the A complement. B chromosomes found in this population may have a common origin and subsequently diversified in size and morphology.

scholarly journals Evolution of Plant B Chromosome Enriched Sequences

Genes ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 515 ◽  
Author(s):  
André Marques ◽  
Sonja Klemme ◽  
Andreas Houben
Keyword(s):  
Repetitive Sequences ◽  
B Chromosome ◽  
B Chromosomes ◽  
Dna Elements ◽  
Formation And Evolution ◽  
The Subject ◽  
Chromosome Formation ◽  
The Impact ◽  
Normal Standard ◽  
Shed Light

B chromosomes are supernumerary chromosomes found in addition to the normal standard chromosomes (A chromosomes). B chromosomes are well known to accumulate several distinct types of repeated DNA elements. Although the evolution of B chromosomes has been the subject of numerous studies, the mechanisms of accumulation and evolution of repetitive sequences are not fully understood. Recently, new genomic approaches have shed light on the origin and accumulation of different classes of repetitive sequences in the process of B chromosome formation and evolution. Here we discuss the impact of repetitive sequences accumulation on the evolution of plant B chromosomes.

scholarly journals Origin, Behaviour, and Transmission of B Chromosome with Special Reference to Plantago lagopus

Genes ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 152 ◽  
Author(s):  
Manoj Dhar ◽  
Jasmeet Kour ◽  
Sanjana Kaul
Keyword(s):  
Ribosomal Dna ◽  
Dna Sequences ◽  
B Chromosome ◽  
Repetitive Elements ◽  
B Chromosomes ◽  
Current Status ◽  
Sequencing Data ◽  
Molecular Cytogenetic Techniques ◽  
Plantago Lagopus ◽  
Eukaryotic Organisms

B chromosomes have been reported in many eukaryotic organisms. These chromosomes occur in addition to the standard complement of a species. Bs do not pair with any of the A chromosomes and they have generally been considered to be non-essential and genetically inert. However, due to tremendous advancements in the technologies, the molecular composition of B chromosomes has been determined. The sequencing data has revealed that B chromosomes have originated from A chromosomes and they are rich in repetitive elements. In our laboratory, a novel B chromosome was discovered in Plantago lagopus. Using molecular cytogenetic techniques, the B chromosome was found to be composed of ribosomal DNA sequences. However, further characterization of the chromosome using next generation sequencing (NGS) etc. revealed that the B chromosome is a mosaic of sequences derived from A chromosomes, 5S ribosomal DNA (rDNA), 45S rDNA, and various types of repetitive elements. The transmission of B chromosome through the female sex track did not follow the Mendelian principles. The chromosome was found to have drive due to which it was perpetuating in populations. The present paper attempts to summarize the information on nature, transmission, and origin of B chromosomes, particularly the current status of our knowledge in P. lagopus.

Cytogenetic Characterization of Two Metynnis Species (Characiformes, Serrasalmidae) Reveals B Chromosomes Restricted to the Females

2019 ◽  
Vol 158 (1) ◽  
pp. 38-45 ◽  
Author(s):  
Ramon M. Favarato ◽  
Leila Braga Ribeiro ◽  
Rafaela P. Ota ◽  
Celeste M. Nakayama ◽  
Eliana Feldberg
Keyword(s):  
5S Rdna ◽  
B Chromosome ◽  
B Chromosomes ◽  
C Banding ◽  
Retrotransposable Elements ◽  
Rdna Sites ◽  
Species Pairs ◽  
Cytogenetic Characterization ◽  
Female Genome

Karyotypes and chromosomal characteristics with focus on B chromosomes of 2 species of the serrasalmid genus Metynnis, namely M. lippincottianus and M. maculatus, were examined using conventional (C-banding) and molecular (FISH mapping of minor and major rDNAs and Rex1, Rex3, and Rex6 retrotransposable elements) protocols. Both species possessed a diploid chromosome number of 2n = 62 and karyotypes composed of 32 metacentric + 28 submetacentric + 2 subtelocentric and 32 metacentric + 26 submetacentric + 4 subtelocentric, respectively; one small B element was found in the female genome of M. lippincottianus. C-banding revealed heterochromatin in the pericentromeric and terminal portions of all chromosomes of both species; the B chromosome was entirely heterochromatic. FISH showed 18S rDNA sites in 2 chromosome pairs in both species (pairs 19 and 22), and a large block in the B chromosome, while 5S rDNA signals were detected in the first pair of subtelocentric chromosomes in both species, moreover in M. maculatus an additional labeled pair 4 was observed. Mapping of the Rex1, Rex3, and Rex6 retrotransposable elements in the genomes of M. lippincottianus and M. maculatus indicated that they were dispersed throughout nearly all the chromosomes of the complement, except for the B chromosome of M. lippincottianus.

Highly repetitive sequences in B chromosomes of Secale cereale revealed by fluorescence in situ hybridization

Genome ◽  
1994 ◽  
Vol 37 (4) ◽  
pp. 709-712 ◽  
Author(s):  
Angeles Cuadrado ◽  
Nicolas Jouve
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Secale Cereale ◽  
Fluorescent In Situ Hybridization ◽  
Repetitive Sequences ◽  
5S Rdna ◽  
B Chromosomes ◽  
Multigene Families ◽  
Hybridization Probes

An analysis of the presence and distribution of the rye and wheat repeated sequences in rye B chromosomes was carried out by fluorescent in situ hybridization. Probes used consisted of three highly repetitive sequences from rye (pSc119.2, pSc74, and pSc34) and the multigene families for the 25S–5.8S–18S and 5S rDNA from wheat (pTa71 and pTa794, respectively). pSc74 and pSc119.2 showed hybridization signals in the telomeric regions of rye B chromosomes. The remaining DNA clones did not hybridize to the B chromosomes.Key words: Secale cereale, rye, repetitive DNA, fluorescence in situ hybridization, B chromosomes.

scholarly journals Structural and Functional Analysis of Transposable Elements Focusing on B Chromosomes of the Cichlid Fish Astatotilapia latifasciata

2018 ◽  
Author(s):  
Rafael Coan ◽  
Cesar Martins
Keyword(s):  
Transposable Elements ◽  
Repetitive Sequences ◽  
Chromosome Complement ◽  
Cichlid Fish ◽  
B Chromosome ◽  
B Chromosomes ◽  
Sequencing Data ◽  
Taxonomic Groups ◽  
African Cichlids

B chromosomes (B) are supernumerary elements found in many taxonomic groups. Most B chromosomes are rich in heterochromatin and composed of abundant repetitive sequences, especially transposable elements (TEs). Bs origin is generally linked to the A chromosome complement (A). The first report of a B chromosome in African cichlids was on Astatotilapia latifasciata, which can harbor 0, 1 or 2 B chromosomes. Classical cytogenetics studies found high TE content on the species B chromosome. In this study, we aim to understand TE composition and expression on A. latifasciata genome and its relation to the B chromosome. We use bioinformatics analysis to explore TEs genome organization and also their composition on the B chromosome. Bioinformatics findings were validated by fluorescent in situ hybridization (FISH) and real-time PCR (qPCR). A. latifasciata has a TE content similar to other cichlid fishes and several expanded elements on its B chromosome. With RNA sequencing data (RNA-seq) we showed that all major TE classes are transcribed in brain, muscle and male/female gonads. The evaluation of TE expression between B- and B+ individuals showed that few elements have differential expression among groups and expanded B elements were not highly transcribed. Putative silencing mechanisms may the acting on the B chromosome of A. latifasciata to prevent adverse consequences of repeat transcription and mobilization in the genome.

scholarly journals Evolution of Plant B Chromosome Enriched Sequences

2018 ◽  
Author(s):  
André Marques ◽  
Sonja Klemme ◽  
Andreas Houben
Keyword(s):  
Repetitive Sequences ◽  
B Chromosome ◽  
B Chromosomes ◽  
Supernumerary Chromosomes ◽  
Formation And Evolution ◽  
Chromosome Formation ◽  
The Impact ◽  
Normal Standard ◽  
Shed Light

B chromosomes are supernumerary chromosomes which are found in addition to the normal standard chromosomes (A chromosomes). B chromosomes are well known to accumulate several types of repeats. Although the evolution of B chromosomes has been subject of numerous studies, the mechanisms of accumulation and evolution of repetitive sequences is not fully understood. Recently, new genomic approaches have shed light on the origin and accumulation of different classes of repetitive sequences in the process of B chromosome formation and evolution. Here we discuss the impact of repetitive sequences accumulation on the evolution of plant B chromosomes.

scholarly journals B Chromosomes in Grasshoppers: Different Origins and Pathways to the Modern Bs

Genes ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 509 ◽  
Author(s):  
Ilyas Jetybayev ◽  
Alexander Bugrov ◽  
Victoria Dzuybenko ◽  
Nikolay Rubtsov
Keyword(s):  
Repetitive Sequences ◽  
B Chromosome ◽  
B Chromosomes ◽  
Eyprepocnemis Plorans ◽  
Grasshopper Species ◽  
Chromosome Formation ◽  
Different Origins ◽  
Further Development ◽  
New Hypothesis ◽  
Orthopteran Species

B chromosomes (Bs) were described in most taxa of eukaryotes and in around 11.9% of studied Orthopteran species. In some grasshopper species, their evolution has led to many B chromosome morphotypes. We studied the Bs in nine species (Nocaracris tardus, Nocaracris cyanipes, Aeropus sibiricus, Chorthippus jacobsoni, Chorthippus apricarius, Bryodema gebleri, Asiotmethis heptapotamicus songoricus, Podisma sapporensis, and Eyprepocnemis plorans), analyzing their possible origin and further development. The studied Bs consisted of C-positive or C-positive and C-negative regions. Analyzing new data and considering current hypotheses, we suggest that Bs in grasshoppers could arise through different mechanisms and from different chromosomes of the main set. We gave our special attention to the Bs with C-negative regions and suggest a new hypothesis of B chromosome formation from large or medium autosomes. This hypothesis includes dissemination of repetitive sequences and development of intercalary heterochromatic blocks in euchromatic chromosome arm followed by deletion of euchromatic regions located between them. The hypothesis is based on the findings of the Eyprepocnemis plorans specimens with autosome containing numerous intercalary repeat clusters, analysis of C-positive Bs in Eyprepocnemis plorans and Podisma sapporensis containing intercalary and terminal C-negative regions, and development of heterochromatic neo-Y chromosome in some Pamphagidae grasshoppers.

scholarly journals Spatial organization of fibroblast and spermatocyte nuclei with different B-chromosome content in Korean field mouse, Apodemus peninsulae (Rodentia, Muridae)

Genome ◽  
2017 ◽  
Vol 60 (10) ◽  
pp. 815-824 ◽  
Author(s):  
Tatyana V. Karamysheva ◽  
Anna A. Torgasheva ◽  
Yaroslav R. Yefremov ◽  
Anton G. Bogomolov ◽  
Thomas Liehr ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Spatial Organization ◽  
Constitutive Heterochromatin ◽  
B Chromosome ◽  
B Chromosomes ◽  
Laser Scanning Microscopy ◽  
Field Mouse ◽  
Apodemus Peninsulae ◽  
Basic Set ◽  
Korean Field Mouse

Korean field mouse (Apodemus peninsulae) shows a wide variation in the number of B chromosomes composed of constitutive heterochromatin. For this reason, it provides a good model to study the influence of the number of centromeres and amount of heterochromatin on spatial organization of interphase nuclei. We analyzed the three-dimensional organization of fibroblast and spermatocyte nuclei of the field mice carrying a different number of B chromosomes using laser scanning microscopy and 3D fluorescence in situ hybridization. We detected a co-localization of the B chromosomes with constitutive heterochromatin of the chromosomes of the basic set. We showed a non-random distribution of B chromosomes in the spermatocyte nuclei. Unpaired B chromosomes showed a tendency to occur in the compartment formed by the unpaired part of the XY bivalent.

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