scholarly journals B chromosomes and structural hybridity in Petunia hybrida Vilm.

CYTOLOGIA ◽  
1980 ◽  
Vol 45 (4) ◽  
pp. 763-768
Author(s):  
R. N. Gohil ◽  
Ranjana Kaul
Keyword(s):  
Petunia Hybrida ◽  
B Chromosomes ◽  
Structural Hybridity

Structural hybridity and supernumerary chromosomes in a diploid Tradescantia hirsuticaulis

1975 ◽  
Vol 53 (5) ◽  
pp. 456-465 ◽  
Author(s):  
C. C. Chinnappa
Keyword(s):  
Reciprocal Translocation ◽  
Cytological Study ◽  
B Chromosomes ◽  
The Other ◽  
Meiotic Pairing ◽  
Structural Hybridity ◽  
Supernumerary Chromosomes

Cytological study of a diploid (2n = 12) population of Tradescantia hirsuticaulis Small from Stone Mountain, Georgia, revealed striking variation in four plants growing in a cluster, indicating that they constitute different genotypes. The occurrence of B chromosomes, fragments, and aneusomaty in the plants is associated with structural hybridity in the chromosomes. Two plants were homozygotes with simple meiotic pairing, one was heterozygous for a reciprocal translocation, and the other was a heterozygote for two interchanges as well as for inversions. The behavior and the origin of B chromosomes, fragments, and structural hybridity are discussed.

Natural abundances of 15N and 13C indicating physiological responses in Petunia hybrida to infection by longidorid nematodes and nepoviruses

Nematology ◽  
1999 ◽  
Vol 1 (3) ◽  
pp. 315-320 ◽  
Author(s):  
Roy Neilson ◽  
Linda L. Handley ◽  
David Robinson ◽  
Charlie M. Scrimgeour ◽  
Derek J.F. Brown
Keyword(s):  
Nitric Oxide ◽  
Virus Infection ◽  
Petunia Hybrida ◽  
Physiological Responses ◽  
Pr Proteins ◽  
Pathogen Infection ◽  
Infection Virale ◽  
Longidorus Elongatus ◽  
And Control ◽  
Xiphinema Diversicaudatum

Abstract The effects of a) systemic virus infection (arabis mosaic and tomato black ring nepoviruses), b) ectoparasitic nematode feeding (Xiphinema diversicaudatum and Longidorus elongatus) and c) a combination of virus infection and nematode feeding on the natural abundances of 13C(delta13C) and 15N(delta15N) of nitrogen-starved Petunia hybrida were studied. Pathogen-induced effects were not confined to sites of virus infection or nematode feeding. Those treatments with nematodes feeding on Petunia hosts and those with a combination of virus infection and nematode feeding resulted in a depletion of shoot and root 15N compared with controls. Virus-infected plants were more 15N-enriched than those fed upon by nematodes which, in turn, were more 15N-enriched than those with both nematode and virus in combination. Shoot delta13C values from infected treatments were not significantly different from controls. Although root delta13C was significantly different from controls in most treatments, absolute differences were small. Differences in delta15N between infected and control plants were probably caused by physiological responses to pathogen infection/feeding such as production of PR-proteins and/or release of nitric oxide. Le contenu naturel en 15N et 13C comme indicateur de la reaction de Petunia hybrida a l'infestation par les nematodes Longidorides et les nepovirus - La presente etude a porte sur l'influence i) d'une infection virale systemique (nepovirus de la mosaique Arabis et du cercle noir de la tomate), ii) d'une atteinte par des nematodes ectoparasites (Xiphinema diversicaudatum et Longidorus elongatus) et iii) d'une combinaison de deux types de pathogenes sur le contenu naturel en 13C(delta13C) et en 15N(delta15N) de Petunia hybrida deficients en azote. Les effets induits par ces organismes pathogenes ne sont pas limites aux sites de l'infection virale ou a ceux des attaques des nematodes. Compares aux temoins, les traitements comportant les seules attaques de nematodes et ceux comportant des attaques combinees des deux types de parasites provoquent une diminution du 15N des racines et des parties aeriennes. Les plants infectes par les virus avaient un taux en 15N plus eleve que ceux attaques par les nematodes, lesquels, en revanche, contenaient plus de 15N que les plants soumis simultanement aux deux types de parasites. Les taux de delta13C dans les parties aeriennes des plants soumis aux differentes attaques n'etaient pas significativement differents de ceux des temoins. Si, dans la plupart des traitements, les taux de delta13C dans les racines etaient significativement differents de ceux des temoins, ces differences restaient faibles en valeur absolue. Les differences dans les taux en delta15N entre plants infectes et temoins sont probablement la resultante de reactions physiologiques aux pathogenes, telles la production de proteines PR ou l'emission d'oxyde nitrique.

scholarly journals Chromosomal Instability at Fragile Sites in Blue Foxes, Silver Foxes, and Their Interspecific Hybrids

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1743
Author(s):  
Marta Kuchta-Gładysz ◽  
Ewa Wójcik ◽  
Anna Grzesiakowska ◽  
Katarzyna Rymuza ◽  
Olga Szeleszczuk
Keyword(s):  
Interspecific Hybrids ◽  
Genome Stability ◽  
Diploid Number ◽  
Fragile Sites ◽  
B Chromosomes ◽  
Silver Fox ◽  
Chromosomal Breaks ◽  
Blue Fox ◽  
Chromosomal Fragile Sites ◽  
Karyotypic Variation

A cytogenetic assay based on fragile sites (FS) enables the identification of breaks, chromatid gaps, and deletions. In healthy individuals, the number of these instabilities remains low. Genome stability in these species is affected by Robertsonian translocations in the karyotype of the blue fox and by B chromosomes in the silver fox. The aims of the study were to characterise the karyotype of blue foxes, silver foxes, and their hybrids and to identify chromosomal fragile sites used to evaluate genome stability. The diploid number of A chromosomes in blue foxes ranged from 48 to 50, while the number of B chromosomes in silver foxes varied from one to four, with a constant number of A chromosomes (2n = 34). In interspecific hybrids, both types of karyotypic variation were identified, with the diploid number of A chromosomes ranging from 40 to 44 and the number of B chromosomes varying from 0 to 3. The mean frequency of FS in foxes was 4.06 ± 0.19: 4.61 ± 0.37 in blue foxes, 3.46 ± 0.28 in silver foxes, and 4.12 ± 0.22 in hybrids. A relationship was identified between an increased number of A chromosomes in the karyotype of the hybrids and the frequency of chromosomal breaks. The FS assay was used as a biomarker for the evaluation of genomic stability in the animals in the study.

scholarly journals New Data on Organization and Spatial Localization of B-Chromosomes in Cell Nuclei of the Yellow-Necked Mouse Apodemus flavicollis

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1819
Author(s):  
Tatyana Karamysheva ◽  
Svetlana Romanenko ◽  
Alexey Makunin ◽  
Marija Rajičić ◽  
Alexey Bogdanov ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Sex Chromosomes ◽  
Interphase Nucleus ◽  
Spatial Organization ◽  
Three Dimensional ◽  
Dna Probes ◽  
B Chromosomes ◽  
Apodemus Flavicollis ◽  
Yellow Necked Mouse

The gene composition, function and evolution of B-chromosomes (Bs) have been actively discussed in recent years. However, the additional genomic elements are still enigmatic. One of Bs mysteries is their spatial organization in the interphase nucleus. It is known that heterochromatic compartments are not randomly localized in a nucleus. The purpose of this work was to study the organization and three-dimensional spatial arrangement of Bs in the interphase nucleus. Using microdissection of Bs and autosome centromeric heterochromatic regions of the yellow-necked mouse (Apodemus flavicollis) we obtained DNA probes for further two-dimensional (2D)- and three-dimensional (3D)- fluorescence in situ hybridization (FISH) studies. Simultaneous in situ hybridization of obtained here B-specific DNA probes and autosomal C-positive pericentromeric region-specific probes further corroborated the previously stated hypothesis about the pseudoautosomal origin of the additional chromosomes of this species. Analysis of the spatial organization of the Bs demonstrated the peripheral location of B-specific chromatin within the interphase nucleus and feasible contact with the nuclear envelope (similarly to pericentromeric regions of autosomes and sex chromosomes). It is assumed that such interaction is essential for the regulation of nuclear architecture. It also points out that Bs may follow the same mechanism as sex chromosomes to avoid a meiotic checkpoint.

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.

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