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.

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.

scholarly journals Interspecific cytogenetic relationships in three Acestrohynchus species (Acestrohynchinae, Characiformes) reveal the existence of possible cryptic species

2020 ◽  
Vol 14 (1) ◽  
pp. 27-42
Author(s):  
Alber Sousa Campos ◽  
Ramon Marin Favarato ◽  
Eliana Feldberg
Keyword(s):  
Chromosome Pair ◽  
Organizer Region ◽  
Nucleolus Organizer Region ◽  
5S Rdna ◽  
Nucleolus Organizer ◽  
Telomeric Sequences ◽  
Interstitial Telomeric Sequences ◽  
Rdna Sites ◽  
Species Specific

The karyotypes and chromosomal characteristics of three Acestrorhynchus Eigenmann et Kennedy, 1903 species were examined using conventional and molecular protocols. These species had invariably a diploid chromosome number 2n = 50. Acestrorhynchus falcatus (Block, 1794) and Acestrorhynchus falcirostris (Cuvier, 1819) had the karyotype composed of 16 metacentric (m) + 28 submetacentric (sm) + 6 subtelocentric (st) chromosomes while Acestrorhynchus microlepis (Schomburgk, 1841) had the karyotype composed of 14m+30sm+6st elements. In this species, differences of the conventional and molecular markers between the populations of Catalão Lake (AM) and of Apeu Stream (PA) were found. Thus the individuals of Pará (Apeu) were named Acestrorhynchus prope microlepis. The distribution of the constitutive heterochromatin blocks was species-specific, with C-positive bands in the centromeric and telomeric regions of a number of different chromosomes, as well as in interstitial sites and completely heterochromatic arms. The phenotypes of nucleolus organizer region (NOR) were simple, i. e. in a terminal position on the p arm of pair No. 23 except in A. microlepis, in which it was located on the q arm. Fluorescence in situ hybridization (FISH) revealed 18S rDNA sites on one chromosome pair in karyotype of A. falcirostris and A. prope microlepis (pair No. 23) and three pairs (Nos. 12, 23, 24) in A. falcatus and (Nos. 8, 23, 24) in A. microlepis; 5S rDNA sites were detected in one chromosome pair in all three species. The mapping of the telomeric sequences revealed terminal sequences in all the chromosomes, as well as the presence of interstitial telomeric sequences (ITSs) in a number of chromosome pairs. The cytogenetic data recorded in the present study indicate that A. prope microlepis may be an unnamed species.

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 Comparative molecular cytogenetics in Melipona Illiger species (Hymenoptera, Apidae)

Sociobiology ◽  
2018 ◽  
Vol 65 (4) ◽  
pp. 696 ◽  
Author(s):  
Vanderly Andrade-Souza ◽  
Olivia Maria Pereira Duarte ◽  
Cinthia Caroline Cardoso Martins ◽  
Igor Silva Santos ◽  
Márcio Gilberto Cardoso Costa ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Chromosome Number ◽  
Fluorescent In Situ Hybridization ◽  
Molecular Cytogenetics ◽  
Fluorochrome Staining ◽  
Rdna Sites ◽  
Cytogenetic Studies ◽  
Melipona Species ◽  
Almost All

Cytogenetic studies in Melipona are scarce with only 24 species analyzed cytogenetically. Of these, six species had the rDNA sites physically mapped and characterized by Fluorescent in situ Hybridization (fish). The aim of this study was to perform karyotype analyzes on Melipona species from different regions of Brazil, with a greater sampling representative of the Amazonian fauna and using conventional, fluorochrome staining and FISH with heterologous rDNA probes. The predominant chromosome number was 2n = 18, however, the subspecies M. seminigra abunensis and M. s. pernigra showed 2n = 22 chromosomes. The karyotypes were symmetrical, however M. bicolor, M. quadrifasciata, M. flavolineata, M. fuscopilosa, M. nebulosa presented the first pair heteromorphic in length. CMA3+ blocks also exhibited heteromorphism of size and in almost all cases coincided with rDNA sites, except for M. crinita and M. nebulosa, which presented additional non-coincident CMA3+ blocks. The CMA/ rDNA sites were terminal and interstitial in species with high heterochromatic content, and pericentromeric in those species with low heterochromatic content. In addition to pointing out cytogenetic features of cytotaxonomic importance, the reorganization of the genome in Melipona is discussed.

scholarly journals Monocentric chromosomes in Juncus (Juncaceae) and implications for the chromosome evolution of the family

2019 ◽  
Vol 191 (4) ◽  
pp. 475-483 ◽  
Author(s):  
Marcelo Guerra ◽  
Tiago Ribeiro ◽  
Leonardo P Felix
Keyword(s):  
In Situ Hybridization ◽  
Fluorescent In Situ Hybridization ◽  
Chromosome Evolution ◽  
Holocentric Chromosomes ◽  
Mitotic Chromosomes ◽  
Restricted Area ◽  
Rdna Sites ◽  
The Family ◽  
Meiotic Analyses

Abstract Holocentric chromosomes are rare among angiosperms, but have been suggested to be shared by all or most of the species of Cyperaceae and Juncaceae. However, no clear demonstration of the centromere type in Juncus, the largest genus of Juncaceae, has so far been published. Thus, we conducted a detailed chromosomal investigation of four Juncus spp. aiming to identify their centromere type. Mitotic chromosomes were analysed using the fluorochromes CMA and DAPI, fluorescent in situ hybridization (FISH) with rDNA probes and immunodetection of histones H3 phosphorylated at serine 10 (H3-S10ph) and H2A phosphorylated at threonine 133 (H2A-T133ph). DAPI-stained chromosomes of all species displayed typical primary constrictions, which were not related to AT-poor CMA+ heterochromatin or rDNA sites (usually negatively stained with DAPI). Immunodetection with H3-S10ph and H2A-T133ph revealed hyperphosphorylation of pericentromeric and centromeric regions, respectively, in a restricted area, as observed in monocentric chromosomes. Meiotic analyses in J. microcephalus showed no indication of inverted meiosis, commonly found in plants with holocentric chromosomes. Since the species investigated here belong to four different sections of Juncus and all of them display typical monocentric chromosomes, it seems that this kind of centromere is common in the genus and may represent the standard centromere organization for Juncus. If Juncus has monocentric chromosomes, there is no reason to hypothesize that other genera of Juncaceae for which centromeres have not been carefully investigated have holocentric chromosomes.

Genomic affinities in Turnera (subseries Turnera, Turneraceae) inferred by in situ hybridization techniques

Genome ◽  
2010 ◽  
Vol 53 (8) ◽  
pp. 594-598 ◽  
Author(s):  
Alicia López ◽  
Aveliano Fernández ◽  
Lidia Poggio
Keyword(s):  
In Situ Hybridization ◽  
Fluorescent In Situ Hybridization ◽  
Secondary Constriction ◽  
Meiotic Pairing ◽  
Ploidy Levels ◽  
Rdna Sites ◽  
Strong Hybridization ◽  
Strong Hybridization Signal ◽  
Molecular Affinity

Subseries Turnera comprises a polyploid complex with ploidy levels ranging from diploid (2n = 2x = 10) to octoploid (2n = 8x = 40). The use of fluorescent in situ hybridization greatly improved the knowledge of the karyotypes of Turnera species by detecting and mapping rDNA sites. Interspecific variability in the number of sites was detected, but not in correlation with the ploidy level. A chromosome pair with a strong hybridization signal was always visible and this signal corresponded to the secondary constriction detectable by conventional techniques. Genomic in situ hybridization experiments combined with information on meiotic pairing in species and interspecific hybrids revealed that homologies detected by molecular analysis are greater than those detected by chromosome pairing. This suggests that the formation of the allopolyploids could involve species more closely related than previously assumed. Despite the molecular affinity among the genomes, the meiotic pairing is probably controlled by specific genes that restrict homeologous pairing in polyploids.

scholarly journals First cytogenetic characterization of the Amazon Catfish Leiarius marmoratus (Gill, 1870) and its hybrid with Pseudoplatystoma reticulatum (Eigenmann & Eigenmann, 1889)

Caryologia ◽  
2021 ◽  
Vol 74 (1) ◽  
pp. 127-133
Author(s):  
Fernanda Dotti do Prado ◽  
Andrea Abrigato de Freitas Mourão ◽  
Fausto Foresti ◽  
José Augusto Senhorini ◽  
Fabio Porto-Foresti
Keyword(s):  
Organizer Region ◽  
Nucleolus Organizer Region ◽  
5S Rdna ◽  
Nucleolus Organizer ◽  
Intraindividual Variation ◽  
Nucleolar Dominance ◽  
Rdna Sites ◽  
Telocentric Chromosomes ◽  
Cytogenetic Characterization

This study reports the first cytogenetic characterization of the Amazonian catfish Leiarius marmoratus (“jandiá”) and its F1 (first generation) hybrid “cachandiá” with Pseudoplatystoma reticulatum (“cachara”). A diploid number of 56 chromosomes and a single argyrophilic nucleolus organizer region (Ag-NOR) in the short arm of two sub-telocentric chromosomes were observed for both L. marmoratus and P. reticulatum, but with differences in the karyotype formula and the size of the chromosome pair with NORs. The hybrid showed 2n = 56 chromosomes with an intermediate karyotype when compared to the parental species. A single Ag-NOR was maintained in the hybrid but located in two chromosomes with marked differences in size and presenting intraindividual variation in NOR activity (nucleolar dominance). For L. marmoratus and the hybrid, heterochromatic bands were predominately distributed in the terminal, centromeric, and sub-centromeric regions of some chromosomes and 5S rDNA sites located in two distinct sub-telocentric chromosomes, similar to the previously described for P. reticulatum. The data suggested that the hybrid karyotype might be insufficient for a precise discrimination of hybrids, however, Ag-NOR can be used as a chromosome marker to differentiate “cachandiá” from L. marmoratus and P. reticulatum. The current study also provides insights into the chromosomal features of L. marmoratus and contributes with novel cytogenetic information of this native Amazonian catfish included in the Pimelodidae family.

Cytological studies of the nucleolus organizing regions in the Medicago complex: sativa–coerulea–falcata

Genome ◽  
1996 ◽  
Vol 39 (5) ◽  
pp. 914-920 ◽  
Author(s):  
O. Calderini ◽  
F. Pupilli ◽  
P. D. Cluster ◽  
A. Mariani ◽  
S. Arcioni
Keyword(s):  
In Situ Hybridization ◽  
Silver Nitrate ◽  
Fluorescent In Situ Hybridization ◽  
Diploid Species ◽  
2N Gametes ◽  
Root Tip ◽  
Medicago Falcata ◽  
Rdna Sites ◽  
Silver Nitrate Staining

A cytological examination of the nucleolus organizing regions (NORs) of three species from the Medicago sativa complex was conducted to evaluate the structural and functional evolution of the ribosomal RNA (rRNA) loci that encode the 18S, 5.8S, and 26S rRNAs. Mitotic chromosomes in root-tip preparations from tetraploid M. sativa and diploids Medicago coerulea and Medicago falcata were visualized by four methods that provide new data. Fluorescent in situ hybridization using the M. sativa 18S gene as probe localized the structural rDNA to the constricted regions of the satellited chromosomes only. Chromomycin A3 (CMA3) staining and 4′,6-diamidino-2-phenylindole (DAPI) staining identified these chromosomal segments as the most GC-rich regions in the alfalfa karyotype. Medicago falcata exhibited fewer DAPI bands and chromocenters than did M. sativa and M. coerulea. Positive silver nitrate staining showed that all four rDNA regions in M. sativa (located in two chromosome pairs) and both rDNA sites in both diploid species remain transcriptionally active. Counts of nucleoli confirmed that all rDNA regions are independently capable of nucleolus organization. Thus, the number of active NORs in M. sativa is double the number found in M. coerulea or M. falcata. Consequently, if M. sativa originated from sexual hybridization of 2n gametes involving one or both diploid species, no major reorganization or loss of structural or functional rDNA loci has occurred. Key words : alfalfa evolution, CMA3 banding, DAPI banding, fluorescent in situ hybridization, silver nitrate staining.

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