scholarly journals Subgenome Discrimination in Brassica and Raphanus Allopolyploids Using Microsatellites

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2358
Author(s):  
Nicole Bon Campomayor ◽  
Nomar Espinosa Waminal ◽  
Byung Yong Kang ◽  
Thi Hong Nguyen ◽  
Soo-Seong Lee ◽  
...  
Keyword(s):  
Genome Rearrangement ◽  
Brassica Species ◽  
Root Systems ◽  
Telomeric Repeat ◽  
45S Rdna ◽  
Homologous Chromosomes ◽  
Microsatellite Repeats ◽  
Rdna Array ◽  
Homologous Chromosome Pairing

Intergeneric crosses between Brassica species and Raphanus sativus have produced crops with prominent shoot and root systems of Brassica and R. sativus, respectively. It is necessary to discriminate donor genomes when studying cytogenetic stability in distant crosses to identify homologous chromosome pairing, and microsatellite repeats have been used to discriminate subgenomes in allopolyploids. To identify genome-specific microsatellites, we explored the microsatellite content in three Brassica species (B. rapa, AA, B. oleracea, CC, and B. nigra, BB) and R. sativus (RR) genomes, and validated their genome specificity by fluorescence in situ hybridization. We identified three microsatellites showing A, C, and B/R genome specificity. ACBR_msat14 and ACBR_msat20 were detected in the A and C chromosomes, respectively, and ACBR_msat01 was detected in B and R genomes. However, we did not find a microsatellite that discriminated the B and R genomes. The localization of ACBR_msat20 in the 45S rDNA array in ×Brassicoraphanus 977 corroborated the association of the 45S rDNA array with genome rearrangement. Along with the rDNA and telomeric repeat probes, these microsatellites enabled the easy identification of homologous chromosomes. These data demonstrate the utility of microsatellites as probes in identifying subgenomes within closely related Brassica and Raphanus species for the analysis of genetic stability of new synthetic polyploids of these genomes.

scholarly journals Molecular cytogenetic studies in Chenopodium quinoa and Amaranthus caudatus

2014 ◽  
Vol 70 (2) ◽  
pp. 85-90 ◽  
Author(s):  
Jolanta Małuszyńska ◽  
Luz Gomez Pando ◽  
Bożena Kolano
Keyword(s):  
In Situ Hybridization ◽  
Fluorescent In Situ Hybridization ◽  
Chenopodium Quinoa ◽  
45S Rdna ◽  
Fluorescence Staining ◽  
Dapi Staining ◽  
Amaranthus Caudatus ◽  
Homologous Chromosomes ◽  
Molecular Cytogenetic

<em>Chenopodium quinoa</em> Wild. and <em>Amaranthus caudatus</em> L., two plant species from South America, have small and numerous chromosomes. Looking for chromosome markers to distinguish pairs of homologous chromosomes double fluorescence staining, in situ hybridization with 45S rDNA and silver staining were applied. Fluorescent in situ hybridization with 45S rDNA has shown two sites of hybridization occurring on one pair of chromosomes in qunion genre (lines PQ-1, PQ-8). The number of RDA loci in Amaranth's caudate L. genre depends on the accession. Kiwicha 3 line has one pair of chromosomes with signals and Kiwicha Molinera cultivar two pairs. All observed rDNA loci were active. After chromomycin/DAPI staining in all cases, except Kiwicha Molinera cultivar, the CMA<sub>3</sub> positive bands co-localized with signals of in situ hybridization with rDNA. In Kiwicha Molinera the number of CMA<sup>+</sup> bands was higher than the number of 45S rDNA signals after FISH.

scholarly journals Homologous Chromosome Pairing in Drosophila melanogaster Proceeds through Multiple Independent Initiations

1998 ◽  
Vol 141 (1) ◽  
pp. 5-20 ◽  
Author(s):  
Jennifer C. Fung ◽  
Wallace F. Marshall ◽  
Abby Dernburg ◽  
David A. Agard ◽  
John W. Sedat
Keyword(s):  
Three Dimensional ◽  
Motion Model ◽  
Homologous Pairing ◽  
Directed Motion ◽  
Homologous Chromosomes ◽  
Egg Deposition ◽  
Homologous Chromosome Pairing ◽  
Chromosome Arm ◽  
Kinetics Of

The dynamics by which homologous chromosomes pair is currently unknown. Here, we use fluorescence in situ hybridization in combination with three-dimensional optical microscopy to show that homologous pairing of the somatic chromosome arm 2L in Drosophila occurs by independent initiation of pairing at discrete loci rather than by a processive zippering of sites along the length of chromosome. By evaluating the pairing frequencies of 11 loci on chromosome arm 2L over several timepoints during Drosophila embryonic development, we show that all 11 loci are paired very early in Drosophila development, within 13 h after egg deposition. To elucidate whether such pairing occurs by directed or undirected motion, we analyzed the pairing kinetics of histone loci during nuclear cycle 14. By measuring changes of nuclear length and correlating these changes with progression of time during cycle 14, we were able to express the pairing frequency and distance between homologous loci as a function of time. Comparing the experimentally determined dynamics of pairing to simulations based on previously proposed models of pairing motion, we show that the observed pairing kinetics are most consistent with a constrained random walk model and not consistent with a directed motion model. Thus, we conclude that simple random contacts through diffusion could suffice to allow pairing of homologous sites.

A Technique for the Periodic Observation of Root Systems in Situ 1

1962 ◽  
Vol 54 (1) ◽  
pp. 56-56 ◽  
Author(s):  
T. J. Muzik ◽  
J. W. Whitworth
Keyword(s):  
Root Systems

scholarly journals Lateral Elements Inside Synaptonemal Complex-Like Polycomplexes in ndt80 Mutants of Yeast Bind DNA

Genetics ◽  
2003 ◽  
Vol 163 (2) ◽  
pp. 539-544 ◽  
Author(s):  
Hasanuzzaman Bhuiyan ◽  
Gunilla Dahlfors ◽  
Karin Schmekel
Keyword(s):  
In Situ Hybridization ◽  
Electron Microscope ◽  
Synaptonemal Complex ◽  
Immunoelectron Microscopy ◽  
Meiotic Prophase ◽  
Lateral Element ◽  
Homologous Chromosomes ◽  
Meiotic Prophase I ◽  
Dna Antibodies

Abstract The synaptonemal complex (SC) keeps the synapsed homologous chromosomes together during pachytene in meiotic prophase I. Structures that resemble stacks of SCs, polycomplexes, are sometimes found before or after pachytene. We have investigated ndt80 mutants of yeast, which arrest in pachytene. SCs appear normal in spread chromosome preparations, but are only occasionally found in intact nuclei examined in the electron microscope. Instead, large polycomplexes occur in almost every ndt80 mutant nucleus. Immunoelectron microscopy using DNA antibodies show strong preferential labeling to the lateral element parts of the polycomplexes. In situ hybridization using chromosome-specific probes confirms that the chromosomes in ndt80 mutants are paired and attached to the SCs. Our results suggest that polycomplexes can be involved in binding of chromosomes and possibly also in synapsis.

Comparative Karyotype Investigations in the European Crayfish Astacus astacus and A. leptodactylus (Decapoda, Astacidae)

Crustaceana ◽  
2011 ◽  
Vol 84 (12-13) ◽  
pp. 1497-1510 ◽  
Author(s):  
M. Pavlica ◽  
M. Mcžić ◽  
G. Klobučar ◽  
M. Šrut ◽  
I. Maguire ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Chromosome Complement ◽  
Size Difference ◽  
45S Rdna ◽  
Astacus Astacus ◽  
Fluorochrome Staining ◽  
Rdna Sites ◽  
Freshwater Habitats ◽  
Acrocentric Chromosomes

AbstractThis study reports on the chromosome number and karyological characteristics of the endangered species of European crayfish, Astacus astacus and A. leptodactylus (Decapoda, Astacidae), both native to Croatian freshwater habitats. The karyotype of A. astacus and A. leptodactylus consists of 2n = 176 and 2n = 180 chromosomes, respectively. The haploid chromosome complement of A. astacus consists of 52 metacentric, 35 metacentric-submetacentric, and 1 acrocentric chromosomes. Fluorochrome staining with 4,6-diamino-2-phenylindole (DAPI) has revealed that the karyotypes of A. astacus and A. leptodactylus are characterized by large heterochromatic blocks located at centromeric and intercalary positions on the chromosomes. Interstitial heterochromatic blocks were more frequent in A. astacus than in A. leptodactylus. In both species pairing of chromosomes in meiosis was regular with the majority of bivalents in a ring- and a dumbbell-form. Fluorescence in situ hybridization (FISH) has revealed that two 45S rDNA loci were present in the investigated species. In A. astacus one of the two 45S rDNA-bearing chromosome pairs was highly heteromorphic, exhibiting a three-fold size difference between 45S rDNA sites on homologous chromosomes. Such a size difference was significantly less pronounced in A. leptodactylus. The karyotype differences between A. astacus and A. leptodactylus suggest changes in chromosome number as well as position of repetitive DNAs have played a role in the karyotype evolution of the species of Astacus.

scholarly journals Mitotic antipairing of homologous and sex chromosomes via spatial restriction of two haploid sets

2018 ◽  
Vol 115 (52) ◽  
pp. E12235-E12244 ◽  
Author(s):  
Lisa L. Hua ◽  
Takashi Mikawa
Keyword(s):  
Genome Instability ◽  
Cell Types ◽  
Parental Origin ◽  
Meridional Plane ◽  
Homologous Chromosomes ◽  
Daughter Cells ◽  
Homologous Chromosome Pairing ◽  
Multiple Cell ◽  
Mouse Cells ◽  
Nuclear Polarity

Pairing homologous chromosomes is required for recombination. However, in nonmeiotic stages it can lead to detrimental consequences, such as allelic misregulation and genome instability, and is rare in human somatic cells. How mitotic recombination is prevented—and how genetic stability is maintained across daughter cells—is a fundamental, unanswered question. Here, we report that both human and mouse cells impede homologous chromosome pairing by keeping two haploid chromosome sets apart throughout mitosis. Four-dimensional analysis of chromosomes during cell division revealed that a haploid chromosome set resides on either side of a meridional plane, crossing two centrosomes. Simultaneous tracking of chromosome oscillation and the spindle axis, using fluorescent CENP-A and centrin1, respectively, demonstrates collective genome behavior/segregation of two haploid sets throughout mitosis. Using 3D chromosome imaging of a translocation mouse with a supernumerary chromosome, we found that this maternally derived chromosome is positioned by parental origin. These data, taken together, support the identity of haploid sets by parental origin. This haploid set-based antipairing motif is shared by multiple cell types, doubles in tetraploid cells, and is lost in a carcinoma cell line. The data support a mechanism of nuclear polarity that sequesters two haploid sets along a subcellular axis. This topological segregation of haploid sets revisits an old model/paradigm and provides implications for maintaining mitotic fidelity.

scholarly journals Interindividual size heteromorphism of NOR and chromosomal location of 5S rRNA genes in Iheringichthys labrosus

2007 ◽  
Vol 50 (1) ◽  
pp. 141-146 ◽  
Author(s):  
Rafael Augusto de Carvalho ◽  
Ana Lúcia Dias
Keyword(s):  
Chromosomal Location ◽  
5S Rdna ◽  
Rrna Genes ◽  
Telomeric Region ◽  
Fluorescent Staining ◽  
Homologous Chromosomes ◽  
Rdna Probe ◽  
5S Rrna Genes ◽  
Iheringichthys Labrosus

Twenty-five specimens of Iheringichthys labrosus from the Capivara Reservoir were analysed cytogenetically. AgNORs were detected in a pair of ST chromosomes, in the telomeric region of the long arm. Some individuals showed size heteromorphism of this region between homologous chromosomes. Treatment with CMA3 displayed GC-rich regions corresponding to the AgNOR pair, plus other fluorescent staining. In situ hybridization by fluorescence (FISH) with the 18S rDNA probe showed only one pair of stained chromosomes, confirming the heteromorphism observed with AgNO3 and CMA3 in some individuals. The 5S rDNA probe revealed telomeric staining on the long arm of a pair of chromosomes of the ST-A group, probably different from the NOR pair.

Different distributions of homologous chromosomes in adult human Sertoli cells and in lymphocytes signify nuclear differentiation

1996 ◽  
Vol 109 (4) ◽  
pp. 773-776 ◽  
Author(s):  
A.C. Chandley ◽  
R.M. Speed ◽  
A.R. Leitch
Keyword(s):  
Sertoli Cells ◽  
Cell Types ◽  
Fish Analysis ◽  
Cell Nuclei ◽  
Interphase Nuclei ◽  
Homologous Chromosomes ◽  
Blood Lymphocytes ◽  
Painting Probes ◽  
Whole Chromosome Painting

Using whole chromosome painting probes for human chromosomes 3,7,8,13,17 and 21 and X and the probe pHY2.1 for the Y chromosome coupled with fluorescent in situ hybridization (FISH) analysis, the distribution of chromosomes is reported in nuclei of Sertoli cells of the adult testis and in stimulated blood lymphocytes. The distribution of chromosomes in the two cell types is significantly different. A strong tendency for each pair of homologues to pair is inferred from the observation of only a single detectable signal in the majority of Sertoli cell nuclei. The sex chromosomes, by contrast, give two clearly separated signals. Interphase nuclei in dividing blood lymphocytes, analysed as controls, also show mainly two separated signals for all non-acrocentric autosomal pairs, but acrocentric pairs no. 13 and 21 show some tendency to associate, probably reflecting satellite association.

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