scholarly journals DNA Environment of Centromeres and Non-Homologous Chromosomes Interactions in Mouse

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3375
Author(s):  
Victor Spangenberg ◽  
Mikhail Losev ◽  
Ilya Volkhin ◽  
Svetlana Smirnova ◽  
Pavel Nikitin ◽  
...  
Keyword(s):  
Y Chromosome ◽  
X Chromosome ◽  
Satellite Dna ◽  
Centromeric Region ◽  
Autosomal Bivalents ◽  
Homologous Chromosomes ◽  
Interdisciplinary Knowledge ◽  
Eukaryotic Genomes

Although the pericentromeric regions of chromosomes that are enriched in tandemly repeated satellite DNA represent a significant part of eukaryotic genomes, they remain understudied, which is mainly due to interdisciplinary knowledge gaps. Recent studies suggest their important role in genome regulation, karyotype stability, and evolution. Thus, the idea of satellite DNA as a junk part of the genome has been refuted. The integration of data regarding molecular composition, chromosome behaviour, and the details of the in situ organization of pericentromeric regions is of great interest. The objective of this work was a cytogenetic analysis of the interactions between pericentromeric regions from non-homologous chromosomes in mouse spermatocytes using immuno-FISH. We analysed two events: the associations between centromeric regions of the X chromosome and autosomes and the associations between the centromeric regions of the autosomal bivalents that form chromocenters. We concluded that the X chromosome forms temporary synaptic associations with different autosomes in early meiotic prophase I, which can normally be found until the pachytene–diplotene, without signs of pachytene arrest. These associations are formed between the satellite-DNA-rich centromeric regions of the X chromosome and different autosomes but do not involve the satellite-DNA-poor centromeric region of the Y chromosome. We suggest the hypothetical model of X chromosome competitive replacement from such associations during synaptic correction. We showed that the centromeric region of the X chromosome in association remains free of γH2Ax-dependent chromatin inactivation, while the Y chromosome is completely inactivated. This finding highlights the predominant role of associations between satellite DNA-rich regions of different chromosomes, including the X chromosome. We suppose that X-autosomal transient associations are a manifestation of an additional synaptic disorder checkpoint. These associations are normally corrected before the late diplotene stage. We revealed that the intense spreading conditions that were applied to the spermatocyte I nuclei did not lead to the destruction of stretched chromatin fibers of elongated chromocenters enriched in satellite DNA. The tight associations that we revealed between the pericentromeric regions of different autosomal bivalents and the X chromosome may represent the basis for a mechanism for maintaining the repeats stability in the autosomes and in the X chromosome. The consequences of our findings are discussed.

scholarly journals DNA Environment of Centromeres and Non-homologous Chromosomes Interactions in Mouse

2021 ◽  
Author(s):  
Victor Spangenberg ◽  
Losev Michail ◽  
Volkhin Ilya ◽  
Svetlana Smirnova ◽  
Nikitin Pavel ◽  
...  
Keyword(s):  
Y Chromosome ◽  
X Chromosome ◽  
Satellite Dna ◽  
Meiotic Prophase ◽  
Centromeric Region ◽  
Autosomal Bivalents ◽  
Homologous Chromosomes ◽  
Prophase I ◽  
Meiotic Prophase I ◽  
Minor Satellite

Pericentromeric regions of chromosomes enriched in tandemly repeated satellite DNA although representing a significant part of eukaryotic genomes are still understudied mainly due to interdisciplinary knowledge gaps. Recent studies suggest their important role in genome regulation, karyotype stability and evolution. Thus, the idea of satellite DNA as a junk part of the genome was refuted. Integration of data about molecular composition, chromosome behaviour and details of in situ organization of pericentromeric regions is of great interest. The objective of this work was a cytogenetic analysis of the interactions of pericentromeric regions non-homologous chromosomes in mouse spermatocytes using immuno-FISH. We analysed two events: the associations between cerntomeric regions of X chromosome and autosomes, and associations between centromeric regions of autosomal bivalents forming chromocenters. We conclude that X chromosome form temporary synaptic associations with different autosomes in early meiotic prophase I which normally can be found at pachytene-diplotene without signs of pachytene arrest. These associations are formed between the satellite DNA-enriched centomeric regions of X chromosome and different autosomes but not involve the satellite-poor centromeric region of Y-chromosome. We suggest the mechanism of X chromosome competitive replacement from such associations during synaptic correction. We showed that centromeric region of the X chromosome remains free of γH2Ax-dependent chromatin inactivation, while Y chromosome is completely inactivated. This findings highlights the predominant role of associations between satellite DNA-enriched regions of different chromosomes including X. We assume that X-autosome temporary associations is a manifestation of an additional synaptic disorders checkpoint. These associations are normally corrected before the late diplotene. We revealed that the intense spreading conditions applied to the spermatocytes I nuclei did not lead to destruction of stretched chromatin fibers i.e. elongated chromocenters enriched in satellite DNA. Revealed by us tight associations between pericentromeric regions of different autosomal bivalents and X chromosome may represent the basis for repeat stability maintenance in autosomes an X chromosome. The consequences of our findings are discussed. We obtained the preparations of mouse spermatocytes nuclei in the meiotic prophase I using two approaches: standard and extremely intense surface spread techniques. Using immuno-FISH we visualized tandemly repeated mouse Major and Minor satellite DNA located in the pericentromeric regions of chromosomes and performed a morphological comparison of the standard- and intensely spreaded meiotic nuclei. Based on our results, we assume the remarkable strength of the chromocenter-mediated associations, “chromatin “bridges”, between different bivalents at the pachytene and diplotene stages. We have demonstrated that the chromocenter “bridges” between the centromeric ends of meiotic bivalents are enriched in both tandemly repeated Major and Minor satellite DNA. Association of centromeric regions of autosomal bivalents and X-chromosome but not with Y-chromosome correlates with the absence of Major and Minor satellites on Y-chromosome. We suggest that revealed tight associations between pericentromeric regions of bivalents may represent the network-like system providing dynamic stability of chromosomal territories, as well as add new data for the hypothesis of ectopic recombination in these regions which supports sequence homogeneity between non-homologous chromosomes and does not contradict the meiotic restrictions imposed by the crossing-over interference near centromeres. We conclude that nuclear architecture in meio-sis may play an essential role in contacts between the non-homologous chromosomes providing the specific characteristics of pericentromeric DNA.

scholarly journals Chromosome Y Isodicentrics in two Cases with Ambiguous genitalia and Features of Turner Syndrome

2008 ◽  
Vol 11 (2) ◽  
pp. 51-58
Author(s):  
A Lungeanu ◽  
A Arghir ◽  
S Arps ◽  
G Cardos ◽  
N Dumitriu ◽  
...  
Keyword(s):  
Turner Syndrome ◽  
Y Chromosome ◽  
Ambiguous Genitalia ◽  
Peripheral Blood Lymphocytes ◽  
Chromosome Y ◽  
Y Chromosomes ◽  
New Information ◽  
Pathway Perturbation

Chromosome Y Isodicentrics in two Cases with Ambiguous genitalia and Features of Turner SyndromeKaryotype investigations using classical cytogenetics, fluorescencein situhybridization (FISH) and polymerase chain reaction (PCR) techniques were used for the characterization of Y chromosome structural anomalies found in two patients with ambiguous genitalia and features of Turner syndrome. Both exhibited mosaic karyotypes of peripheral blood lymphocytes. The karyotype was 45, X[90]/ 46, X, idic(Y)(p11.3).ish idic(Y) (wcpY+, DXYS130++,SRY++,DYZ3++,DYZ1++, DYS224++)[10] in one case, and the karyotype was 45, X[65]/46, X, idic(Y) (q11).ish idic(Y)(SRY++, RP11-140H23-)[35] in the other case. Derivative Y chromosomes were different in shape and size and positive for the SRY gene, a common underlying element of ambiguous genitalia phenotypes. These results add new information concerning the role of Y chromosome structural abnormalities in sex determination pathway perturbation which are poorly understood, and highlight the importance of the sex chromosomes integrity for a normal sex phenotype development.

Mapping the mouse X chromosome: possible symmetry in the location of a family of sequences on the mouse X and Y chromosomes

Development ◽  
1987 ◽  
Vol 101 (Supplement) ◽  
pp. 107-116
Author(s):  
Philip Avner ◽  
Colin Bishop ◽  
Laurence Amar ◽  
Jacques Cambrou ◽  
Didier Hatat ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Y Chromosome ◽  
X Chromosome ◽  
Somatic Cell Hybrid ◽  
The Other ◽  
Interspecific Crosses ◽  
Somatic Cell Hybrid Panel ◽  
Mus Spretus ◽  
Y Chromosomes

Major advances in our knowledge of the genetic organization of the mouse X chromosome have been obtained by the use of interspecific crosses involving Mus spretus-derived strains. This system has been used to study sequences detected by three probes 80Y/B, 302Y/B and 371Y/B isolated from a mouse Y-chromosome library which have been shown to recognize both male–female common and male–female differential sequences. These patterns are due to the presence of a family of cross-reacting sequences on the mouse X and Y chromosomes. Detailed genetic analysis of the localization of the X-chromosomespecific sequences using both a somatic cell hybrid panel and an interspecific mouse cross has revealed the presence of at least three discrete clusters of loci (X–Y)A, (X–Y)B and (X–Y)C. Two of these clusters, (X–Y)B and (X–Y)C, lie distally on the mouse X chromosome, the other cluster (X–Y)A being situated close to the centromere. In situ hybridization shows a striking symmetry in the localization of the major sequences on both the X and Y chromosomes detected by these probes, hybridization being preferentially localized to a subcentromeric and subtelomeric region on each chromosome. This striking localization symmetry between the X and Y chromosome sequences is discussed in terms of the extensive pairing of the X–Y chromosomes noted during meiosis.

Analysis of the sex chromosomes of the Mediterranean fruit fly by microdissected DNA probes

Genome ◽  
1998 ◽  
Vol 41 (1) ◽  
pp. 74-78 ◽  
Author(s):  
Ute Willhoeft ◽  
Jutta Mueller-Navia ◽  
Gerald Franz
Keyword(s):  
Y Chromosome ◽  
X Chromosome ◽  
Sex Chromosomes ◽  
Fruit Fly ◽  
Mediterranean Fruit Fly ◽  
Oligonucleotide Primer ◽  
Mitotic Chromosomes ◽  
Degenerate Oligonucleotide ◽  
The Mediterranean

In the Mediterranean fruit fly, Ceratitis capitata, the sex-determining region maps to the long arm of the Y chromosome. DNA from this region of the Y chromosome and, for comparison, from the tip of the long arm of the X chromosome, was isolated by microdissection and amplified by degenerate oligonucleotide primer PCR (DOP-PCR). FISH of the Y-chromosomal microdissection products medY1-medY5 to mitotic chromosomes revealed hybridization signals on most of the long arm of the Y chromosome, including the male-determining region, and on the long arm of the X chromosome, as well as weaker signals on the autosomes, some of which were located in the heterochromatin next to the centromeres. The X-chromosomal microdissected probe medX1 revealed strong signals on the sex chromosomes and randomly distributed signals on the autosomes. Chromosomal in situ suppression hybridization indicates that the Y chromosome contains considerable amounts of Y-enriched and Y-specific sequences and that X-enriched sequences are present on the long arm of the X chromosome. The microdissected probes medY1, medY2, and medX1 hybridize to the sex chromosomes of two closely related species,Ceratitis rosa and Trirhithrum coffeae.

scholarly journals The Role of Satellite DNAs in Genome Architecture and Sex Chromosome Evolution in Crambidae Moths

2021 ◽  
Vol 12 ◽  
Author(s):  
Diogo C. Cabral-de-Mello ◽  
Magda Zrzavá ◽  
Svatava Kubíčková ◽  
Pedro Rendón ◽  
František Marec
Keyword(s):  
Sex Chromosomes ◽  
Ostrinia Nubilalis ◽  
Tandem Repeats ◽  
Chromosome Evolution ◽  
Sex Chromosome ◽  
Satellite Dnas ◽  
Telomere Function ◽  
Eukaryotic Genomes

Tandem repeats are important parts of eukaryotic genomes being crucial e.g., for centromere and telomere function and chromatin modulation. In Lepidoptera, knowledge of tandem repeats is very limited despite the growing number of sequenced genomes. Here we introduce seven new satellite DNAs (satDNAs), which more than doubles the number of currently known lepidopteran satDNAs. The satDNAs were identified in genomes of three species of Crambidae moths, namely Ostrinia nubilalis, Cydalima perspectalis, and Diatraea postlineella, using graph-based computational pipeline RepeatExplorer. These repeats varied in their abundance and showed high variability within and between species, although some degree of conservation was noted. The satDNAs showed a scattered distribution, often on both autosomes and sex chromosomes, with the exception of both satellites in D. postlineella, in which the satDNAs were located at a single autosomal locus. Three satDNAs were abundant on the W chromosomes of O. nubilalis and C. perspectalis, thus contributing to their differentiation from the Z chromosomes. To provide background for the in situ localization of the satDNAs, we performed a detailed cytogenetic analysis of the karyotypes of all three species. This comparative analysis revealed differences in chromosome number, number and location of rDNA clusters, and molecular differentiation of sex chromosomes.

268 IDENTIFICATION OF X- AND Y-BEARING SPERMATOZOA IN SORTED BUFFALO (BUBALUS BUBALIS) SEMEN BY FLUORESCENCE IN SITU HYBRIDIZATION

2009 ◽  
Vol 21 (1) ◽  
pp. 231
Author(s):  
M. Zhang ◽  
X. J. Zhuang ◽  
Y. Q. Lu ◽  
C. H. Hu ◽  
S. S. Lu ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Y Chromosome ◽  
X Chromosome ◽  
Chromosome Painting ◽  
Fish Method ◽  
Painting Probes ◽  
Flow Cytometry Sorting

Flow cytometry sorting technology has been successfully used to sort the X- and Y-chromosome bearing sperm. Previous studies showed that fluorescence in situ hybridization (FISH) method was a simple and reliable procedure for assessing the effectiveness of separation of X- and Y-sperm in the swine (Kawarasaki T et al. 1998 Theriogenology 50, 625–635) and the bovine (Rens W et al. 2001 Reproduction 121, 541–546). Reports of sex-preselection by flow-cytometry sorting of the X- and Y-sperm were also seen in the buffalo (Presicce GA et al. 2005 Reprod. Dom. Anim. 40, 73–75; Lu YQ et al. 2006 Anim. Reprod. Sci. 100, 192–196). There was, however, no report to date for using the FISH method to assess the purity of the sorted buffalo sperm. The objective of the present study was to verify the purity of flow cytometrically-sorted buffalo X- and Y-sperm by FISH using bovine X- and Y- chromosome painting probes prepared by microdissection. The X- and Y- chromosomes of bovidea were microdissected respectively from the metaphase spreads of Holstein blood cells with a glass needle controlled by a micromanipulator and amplified by degenerate oligo-nucleotide primer-PCR (DOP-PCR) (Mariela N et al. 2005 Genet. Mol. Res. 4, 675–683). The DOP-PCR products of X- and Y- chromosome were labeled with CY3-dUTP and Biotin-11-dUTP, respectively. The buffalo X- or Y-sperm DNA from unsorted semen and sorted semen were hybridized to the labeled probes, respectively. The results showed that the hybridized signals were clearly visible in the metaphase karyotype of bovine and buffalo semen samples. About 47.7% (594/1246) and 48.9% (683/1396) of the unsorted buffalo sperm emitted strong fluorescent signals when assessed by Y- and X-chromosome painting probes, respectively, which was conformed to the sex ratio in normal buffalo sperm (50%:50%). About 86.1% (1529/1776) hybridization signals of the sperm in the sorted X-semen assessed by X-chromosome painting probes were detected, while 82.2% (2232/2716) of the Y-sorted buffalo sperm emitted strong fluorescent signals when assessed by Y-chromosome painting probe. The results of the flow cytometer re-analysis revealed that the proportions of X- and Y-bearing sperm in the sorted semen were 89.6% and 86.7%, respectively. There were no apparent differences between the two assessment methods of sperm separation by flow cytometry re-analysis and by FISH with the X-Y paint probe. In conclusion, bovine X- and Y-chromosome painting probes prepared using microisolation method could be used to verify the purity of the sorted sperm in the buffalo. This study was supported by the Guangxi Department of Science and Technology (0626001-3-1) and National Key Technology R&D Program, The People’s Republic of China (2006BAD04A18). The authors (M. Zhang, X.J. Zhuang, and Y.Q. Lu) contributed equally to this work.

scholarly journals Alterations in chromosomal synapses and DNA repair in apoptotic spermatocytes of Mus m. domesticus

2016 ◽  
Vol 60 (2) ◽  
Author(s):  
E. Ayarza ◽  
M. González ◽  
F. López ◽  
R. Fernández-Donoso ◽  
J. Page ◽  
...  
Keyword(s):  
Dna Repair ◽  
Chromatin Remodeling ◽  
High Frequency ◽  
Caspase 9 ◽  
Autosomal Bivalents ◽  
Single Chromosome ◽  
Homologous Chromosomes ◽  
Synaptonemal Complexes ◽  
Dna Repair Proteins

<p>We investigated whether apoptotic spermatocytes from the mouse <em>Mus m. domesticus</em> presented alterations in chromosomal synapses and DNA repair. To enrich for apoptotic spermatocytes, the scrotum’s temperature was raised by partially exposing animals for 15 min to a 42ºC water bath. Spermatocytes in initial apoptosis were identified <em>in situ</em> by detecting activated Caspase-9.  SYCP1 and SYCP3 were markers for evaluating synapses or the structure of synaptonemal complexes and Rad51 and γH2AX for detecting DNA repair and chromatin remodeling. Apoptotic spermatocytes were concentrated in spermatogenic cycle stages III-IV (50.3%), XI-XII (44.1%) and IX-X (4.2%). Among apoptotic spermatocytes, 48% were in middle pachytene, 44% in metaphase and 6% in diplotene. Moreover, apoptotic spermatocytes showed several structural anomalies in autosomal bivalents, including splitting of chromosomal axes and partial asynapses between homologous chromosomes. gH2AX and Rad51 were atypically distributed during pachytene and as late as diplotene and associated with asynaptic chromatin, single chromosome axes or discontinuous chromosome axes. Among apoptotic spermatocytes at pachytene, 70% showed changes in the structure of synapses, 67% showed changes in gH2AX and Rad51 distribution and 50% shared alterations in both synapses and DNA repair. Our results showed that apoptotic spermatocytes from <em>Mus m. domesticus</em> contain a high frequency of alterations in chromosomal synapses and in the recruitment and distribution of DNA repair proteins. Together, these observations suggest that these alterations may have been detected by meiotic checkpoints triggering apoptosis.</p>

The contribution of p53 and Y chromosome long arm genes to regulation of apoptosis in mouse testis

2018 ◽  
Vol 30 (3) ◽  
pp. 469
Author(s):  
Tomasz Lech ◽  
Józefa Styrna ◽  
Katarzyna Kotarska
Keyword(s):  
Germ Cell ◽  
Y Chromosome ◽  
Cell Apoptosis ◽  
P53 Protein ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Germ Cell Apoptosis ◽  
Tumour Suppressor Protein ◽  
Apoptotic Pathways

Apoptosis of excessive or defective germ cells is a natural process occurring in mammalian testes. Tumour suppressor protein p53 is involved in this process both in developing and adult male gonads. Its contribution to testicular physiology is known to be modified by genetic background. The aim of this study was to evaluate the combined influence of the p53 and Y chromosome long arm genes on male germ cell apoptosis. Knockout of the transformation related protein 53 (Trp53) gene was introduced into congenic strains: B10.BR (intact Y chromosome) and B10.BR-Ydel (Y chromosome with a deletion in the long arm). The level of apoptosis in the testes of 19-day-old and 3-month-old male mice was determined using the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate in situ nick-end labelling (TUNEL) method. The study revealed that although p53 is involved in germ cell apoptosis in peripubertal testes, this process can also be mediated by p53-independent mechanisms. However, activation of p53-independent apoptotic pathways in the absence of the p53 protein requires engagement of the multicopy Yq genes and was not observed in gonads of B10.BR-Ydel-p53−/− males. The role of Yq genes in the regulation of testicular apoptosis seems to be restricted to the initial wave of spermatogenesis and is not evident in adult gonads. The study confirmed, instead, that p53 does participate in spontaneous apoptosis in mature testes.

Heterochromatin organization in the nucleus of Indian muntjac (Muntiacus muntjak)

1986 ◽  
Vol 28 (4) ◽  
pp. 628-630 ◽  
Author(s):  
Ram S. Verma ◽  
Jessey P. Jacob ◽  
Arvind Babu
Keyword(s):  
Restriction Endonuclease ◽  
Y Chromosome ◽  
X Chromosome ◽  
General Pattern ◽  
Banding Technique ◽  
Chromosome Y ◽  
Heterochromatic Segment ◽  
Indian Muntjac ◽  
Muntiacus Muntjak

The heterochromatin in Indian muntjac (Muntiacus muntjak) is located at the periphery of primary constrictions of all the chromosomes. The X chromosome contains significantly larger amounts of heterochromatin than the rest of the complement by C-banding technique. However, the small portion of C-band region was found to be resistant by restriction endonuclease HaeIII (5′… GG ↓ CC … 3′) and was clearly visible on the nucleus. Therefore, the position of this large heterochromatic segment is examined at somatic metaphases. The distribution of the heterochromatin of the X chromosome observed in Indian muntjac is contrary to the general pattern observed in other species, i.e., the chromosomes consisting greater amount of heterochromatin are located more peripherally than those with lesser amount. However, the smaller Y chromosome (Y1) is frequently found at the periphery. The present findings suggest that the role of heterochromatin organization in the nucleus vary between different heterochromatic segments of the same species and vary from species to species.Key words: heterochromatin, chromosome, nucleus, metaphase, Muntiacus muntjak.

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