Fluorescent in situ hybridization shows DIPLOSPOROUS located on one of the NOR chromosomes in apomictic dandelions (Taraxacum) in the absence of a large hemizygous chromosomal region

Genome ◽  
2014 ◽  
Vol 57 (11/12) ◽  
pp. 609-620 ◽  
Author(s):  
Radim J. Vašut ◽  
Kitty Vijverberg ◽  
Peter J. van Dijk ◽  
Hans de Jong
Keyword(s):  
In Situ Hybridization ◽  
Fluorescent In Situ Hybridization ◽  
Genetic Model ◽  
Organizer Region ◽  
Nucleolus Organizer Region ◽  
Nucleolus Organizer ◽  
Artificial Chromosomes ◽  
Chromosomal Position ◽  
Apomictic Species

Apomixis in dandelions (Taraxacum: Asteraceae) is encoded by two unlinked dominant loci and a third yet undefined genetic factor: diplosporous omission of meiosis (DIPLOSPOROUS, DIP), parthenogenetic embryo development (PARTHENOGENESIS, PAR), and autonomous endosperm formation, respectively. In this study, we determined the chromosomal position of the DIP locus in Taraxacum by using fluorescent in situ hybridization (FISH) with bacterial artificial chromosomes (BACs) that genetically map within 1.2–0.2 cM of DIP. The BACs showed dispersed fluorescent signals, except for S4-BAC 83 that displayed strong unique signals as well. Under stringent blocking of repeats by C0t-DNA fragments, only a few fluorescent foci restricted to defined chromosome regions remained, including one on the nucleolus organizer region (NOR) chromosomes that contains the 45S rDNAs. FISH with S4-BAC 83 alone and optimal blocking showed discrete foci in the middle of the long arm of one of the NOR chromosomes only in triploid and tetraploid diplosporous dandelions, while signals in sexual diploids were lacking. This agrees with the genetic model of a single dose, dominant DIP allele, absent in sexuals. The length of the DIP region is estimated to cover a region of 1–10 Mb. FISH in various accessions of Taraxacum and the apomictic sister species Chondrilla juncea, confirmed the chromosomal position of DIP within Taraxacum but not outside the genus. Our results endorse that, compared to other model apomictic species, expressing either diplospory or apospory, the genome of Taraxacum shows a more similar and less diverged chromosome structure at the DIP locus. The different levels of allele sequence divergence at apomeiosis loci may reflect different terms of asexual reproduction. The association of apomeiosis loci with repetitiveness, dispersed repeats, and retrotransposons commonly observed in apomictic species may imply a functional role of these shared features in apomictic reproduction, as is discussed.

Detection of ribosomal DNA sites in lentil and chickpea by fluorescent in situ hybridization

Genome ◽  
1994 ◽  
Vol 37 (4) ◽  
pp. 713-716 ◽  
Author(s):  
S. Abbo ◽  
T. E. Miller ◽  
S. M. Reader ◽  
R. P. Dunford ◽  
I. P. King
Keyword(s):  
In Situ Hybridization ◽  
Fluorescent In Situ Hybridization ◽  
Lens Culinaris ◽  
Organizer Region ◽  
Nucleolus Organizer Region ◽  
Nucleolus Organizer ◽  
Rdna Sites ◽  
In The Wild ◽  
Wild Lentil

Hybridization sites of an rDNA probe coding for the 18S, 5.8S, and 26S genes were detected on lentil and chickpea somatic chromosomes using fluorescent in situ hybridization. One pair of hybridization sites was detected in cultivated lentil Lens culinaris L. and wild lentil L. orientalis (Boiss.) Hand.-Mazz., and in both the hybridization sites of the ribosomal probe correspond to the secondary constriction. In cultivated chickpea Cicer arietinum three pairs of rDNA sites were detected and in the wild C. reticulatum two pairs were detected. The karyotypic relationship between the cultivated C. arietinum and its wild progenitor C. reticulatum is discussed.Key words: chickpea, lentil, rDNA sites, nucleolus organizer region, fluorescent in situ hybridization, primer-mediated in situ hybridization.

Primer-induced in situ hybridization to plant chromosomes

Genome ◽  
1993 ◽  
Vol 36 (5) ◽  
pp. 815-817 ◽  
Author(s):  
S. Abbo ◽  
T. E. Miller ◽  
I. P. King
Keyword(s):  
In Situ Hybridization ◽  
Mitotic Chromosome ◽  
Organizer Region ◽  
Nucleolus Organizer Region ◽  
Nucleolus Organizer ◽  
Hybridization Technique ◽  
Plant Chromosomes ◽  
Secale Cereale L ◽  
Future Potential

Primer-induced in situ hybridization of high copy sequences was used successfully on rye mitotic chromosome spreads. Nucleolus organizer sequences were detected in rye, and the pattern obtained was in full agreement with previously reported results by conventional in situ hybridization. The future potential of the primer-induced in situ hybridization technique is briefly discussed.Key words: primer-induced in situ hybridization, rye (Secale cereale L.), nucleolus organizer region.

scholarly journals Comparative Distribution of Repetitive Sequences in the Karyotypes of Xenopus tropicalis and Xenopus laevis (Anura, Pipidae)

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 617
Author(s):  
Álvaro S. Roco ◽  
Thomas Liehr ◽  
Adrián Ruiz-García ◽  
Kateryna Guzmán ◽  
Mónica Bullejos
Keyword(s):  
In Situ Hybridization ◽  
Xenopus Laevis ◽  
Organizer Region ◽  
Repetitive Sequences ◽  
Nucleolus Organizer Region ◽  
Nucleolus Organizer ◽  
Repeated Sequences ◽  
Xenopus Tropicalis ◽  
Model Organisms

Xenopus laevis and its diploid relative, Xenopus tropicalis, are the most used amphibian models. Their genomes have been sequenced, and they are emerging as model organisms for research into disease mechanisms. Despite the growing knowledge on their genomes based on data obtained from massive genome sequencing, basic research on repetitive sequences in these species is lacking. This study conducted a comparative analysis of repetitive sequences in X. laevis and X. tropicalis. Genomic in situ hybridization (GISH) and fluorescence in situ hybridization (FISH) with Cot DNA of both species revealed a conserved enrichment of repetitive sequences at the ends of the chromosomes in these Xenopus species. The repeated sequences located on the short arm of chromosome 3 from X. tropicalis were not related to the sequences on the short arm of chromosomes 3L and 3S from X. laevis, although these chromosomes were homoeologous, indicating that these regions evolved independently in these species. Furthermore, all the other repetitive sequences in X. tropicalis and X. laevis may be species-specific, as they were not revealed in cross-species hybridizations. Painting experiments in X. laevis with chromosome 7 from X. tropicalis revealed shared sequences with the short arm of chromosome 3L. These regions could be related by the presence of the nucleolus organizer region (NOR) in both chromosomes, although the region revealed by chromosome painting in the short arm of chromosome 3L in X. laevis did not correspond to 18S + 28S rDNA sequences, as they did not colocalize. The identification of these repeated sequences is of interest as they provide an explanation to some problems already described in the genome assemblies of these species. Furthermore, the distribution of repetitive DNA in the genomes of X. laevis and X. tropicalis might be a valuable marker to assist us in understanding the genome evolution in a group characterized by numerous polyploidization events coupled with hybridizations.

scholarly journals Defining the Deletion Size in Williams-Beuren Syndrome by Fluorescent In Situ Hybridization with Bacterial Artificial Chromosomes

10.5772/33238 ◽  
2011 ◽  
Author(s):  
Audrey Basinko ◽  
Nathalie Douet-Guilbert ◽  
Severine Audebert-Bellanger ◽  
Philippe Parent ◽  
Clemence Chabay-Vichot ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Fluorescent In Situ Hybridization ◽  
Bacterial Artificial Chromosomes ◽  
Artificial Chromosomes ◽  
Deletion Size

scholarly journals Satellite DNAs Unveil Clues about the Ancestry and Composition of B Chromosomes in Three Grasshopper Species

Genes ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 523 ◽  
Author(s):  
Diogo Milani ◽  
Vanessa Bardella ◽  
Ana Ferretti ◽  
Octavio Palacios-Gimenez ◽  
Adriana Melo ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Fluorescent In Situ Hybridization ◽  
B Chromosome ◽  
B Chromosomes ◽  
Satellite Dnas ◽  
Grasshopper Species ◽  
Repetitive Dnas ◽  
Origin And Evolution ◽  
Chromosomal Position

Supernumerary (B) chromosomes are dispensable genomic elements occurring frequently among grasshoppers. Most B chromosomes are enriched with repetitive DNAs, including satellite DNAs (satDNAs) that could be implicated in their evolution. Although studied in some species, the specific ancestry of B chromosomes is difficult to ascertain and it was determined in only a few examples. Here we used bioinformatics and cytogenetics to characterize the composition and putative ancestry of B chromosomes in three grasshopper species, Rhammatocerus brasiliensis, Schistocerca rubiginosa, and Xyleus discoideus angulatus. Using the RepeatExplorer pipeline we searched for the most abundant satDNAs in Illumina sequenced reads, and then we generated probes used in fluorescent in situ hybridization (FISH) to determine chromosomal position. We used this information to infer ancestry and the events that likely occurred at the origin of B chromosomes. We found twelve, nine, and eighteen satDNA families in the genomes of R. brasiliensis, S. rubiginosa, and X. d. angulatus, respectively. Some satDNAs revealed clustered organization on A and B chromosomes varying in number of sites and position along chromosomes. We did not find specific satDNA occurring in the B chromosome. The satDNAs shared among A and B chromosomes support the idea of putative intraspecific ancestry from small autosomes in the three species, i.e., pair S11 in R. brasiliensis, pair S9 in S. rubiginosa, and pair S10 in X. d. angulatus. The possibility of involvement of other chromosomal pairs in B chromosome origin is also hypothesized. Finally, we discussed particular aspects in composition, origin, and evolution of the B chromosome for each species.

Cytological and molecular evidence of deletion of ribosomal RNA genes in chromosome 6 of barley (Hordeum vulgare)

Genome ◽  
1994 ◽  
Vol 37 (3) ◽  
pp. 419-425 ◽  
Author(s):  
K. Gecheff ◽  
T. Hvarleva ◽  
S. Georgiev ◽  
T. Wilkes ◽  
A. Karp
Keyword(s):  
In Situ Hybridization ◽  
Organizer Region ◽  
Nucleolus Organizer Region ◽  
Molecular Techniques ◽  
The Other ◽  
Rrna Genes ◽  
Molecular Evidence ◽  
Chromosome 6 ◽  
Giemsa Banding

The barley chromosomal mutant T-35, in which only one pair of satellite chromosomes is apparent, was analyzed using a range of cytological and molecular techniques. Using conventional Feulgen staining, Giemsa and silver banding, in situ hybridization, and Southern blot analysis, unequivocal cytological and molecular evidence was obtained that T-35 is a homozygous deletion of rRNA genes residing in the nucleolus organizer region (NOR) of chromosome 6. According to the criteria of arm ratio and Giemsa-banding pattern of this chromosome, the deletion involved the whole NOR, one of the breakpoints being localized in the short arm proximally to the NOR-associated heterochromatic band, the other probably in the satellite of the chromosome. As a result of this deletion, an increased activity of the rRNA genes (as indicated by the size of the silver bands) on the other NOR-bearing chromosome (chromosome 7) was observed. The possible reasons for this phenomenon are discussed.Key words: barley, nucleolar organizing region, deletion, silver and Giemsa banding, in situ hybridization.

scholarly journals Mapping chromosome rearrangement breakpoints to the physical map of Caenorhabditis elegans by fluorescent in situ hybridization.

Genetics ◽  
1993 ◽  
Vol 134 (1) ◽  
pp. 211-219
Author(s):  
D G Albertson
Keyword(s):  
In Situ Hybridization ◽  
Caenorhabditis Elegans ◽  
Fluorescent In Situ Hybridization ◽  
Physical Map ◽  
Chromosome Rearrangements ◽  
Homologous Region ◽  
Genetic Constitution ◽  
Artificial Chromosomes ◽  
Degenerate Oligonucleotide

Abstract A scheme for rapidly mapping chromosome rearrangements relative to the physical map of Caenorhabditis elegans is described that is based on hybridization patterns of cloned DNA on meiotic nuclei, as visualized by fluorescent in situ hybridization. From the nearly complete physical map, DNA clones, in yeast artificial chromosomes (YACs), spanning the rearrangement breakpoint were selected. The purified YAC DNAs were first amplified by degenerate oligonucleotide-primed polymerase chain reaction, then reamplified to incorporate fluorescein dUTP or rhodamine dUTP. The site of hybridization was visualized directly (without the use of antibodies) on meiotic bivalents. This allows chromosome rearrangements to be mapped readily if the duplicated, deficient or translocated regions do not pair with a normal homologous region, because the site or sites of hybridization of the probe on meiotic prophase nuclei will be spatially distinct. The pattern, or number, of hybridization signals from probes from within, or adjacent to, the rearranged region of the genome can be predicted from the genetic constitution of the strain. Characterization of the physical extent of the genetically mapped rearrangements places genetic landmarks on the physical map, and so provides linkage between the two types of map.

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