scholarly journals Molecular Analysis of Nondisjunction in Mice Heterozygous for a Robertsonian Translocation

Genetics ◽  
2002 ◽  
Vol 161 (3) ◽  
pp. 1219-1224
Author(s):  
Lara A Underkoffler ◽  
Laura E Mitchell ◽  
A Russell Localio ◽  
Shannon M Marchegiani ◽  
Justin Morabito ◽  
...  
Keyword(s):  
Molecular Analysis ◽  
Robertsonian Translocation ◽  
Metacentric Chromosome ◽  
Paternal Age ◽  
Chromosome 7 ◽  
Parental Origin ◽  
Molecular Genotyping ◽  
Factors Influencing ◽  
Meiotic Nondisjunction ◽  
Acrocentric Chromosomes

Abstract A Robertsonian translocation results in a metacentric chromosome produced by the fusion of two acrocentric chromosomes. Rb heterozygous mice frequently generate aneuploid gametes and embryos, providing a good model for studying meiotic nondisjunction. We intercrossed mice heterozygous for a (7.18) Robertsonian translocation and performed molecular genotyping of 1812 embryos from 364 litters with known parental origin, strain, and age. Nondisjunction events were scored and factors influencing the frequency of nondisjunction involving chromosomes 7 and 18 were examined. We concluded the following: The frequency of nondisjunction among 1784 embryos (3568 meioses) was 15.9%.Nondisjunction events were distributed nonrandomly among progeny. This was inferred from the distribution of the frequency of trisomics and uniparental disomics (UPDs) among all litters.There was no evidence to show an effect of maternal or paternal age on the frequency of nondisjunction.Strain background did not play an appreciable role in nondisjunction frequency.The frequency of nondisjunction for chromosome 18 was significantly higher than that for chromosome 7 in males.The frequency of nondisjunction for chromosome 7 was significantly higher in females than in males. These results show that molecular genotyping provides a valuable tool for understanding factors influencing meiotic nondisjunction in mammals.

scholarly journals Nondisjunction rates and abnormal embryonic development in a mouse cross between heterozygotes carrying a (7, 18) robertsonian translocation chromosome.

Genetics ◽  
1995 ◽  
Vol 141 (2) ◽  
pp. 667-674 ◽  
Author(s):  
R J Oakey ◽  
P G Matteson ◽  
S Litwin ◽  
S M Tilghman ◽  
R L Nussbaum
Keyword(s):  
Embryonic Development ◽  
Robertsonian Translocation ◽  
Chromosome 7 ◽  
Translocation Chromosome ◽  
Parental Origin ◽  
Paternal Chromosome ◽  
Expected Number ◽  
Genotypic Analysis ◽  
Different Strains ◽  
Robertsonian Chromosome

Abstract Mice bearing Robertsonian translocation chromosomes frequently produce aneuploid gametes. They are therefore excellent tools for studying nondisjunction in mammals. Genotypic analysis of embryos from a mouse cross between two different strains of mice carrying a (7,18) Robertsonian chromosome enabled us to measure the rate of nondisjunction for chromosomes 7 and 18. Embryos (429) were harvested from 76 litters of mice and the parental origin of each chromosome 7 and 18 determined. Genotyping these embryos has allowed us to conclude the following: (1) there were 96 embryos in which at least one nondisjunction event had taken place; (2) the rate of maternal nondisjunction was greater than paternal nondisjunction for teh chromosomes sampled in these mice; (3) a bias against chromosome 7 and 18 nullisomic gametes was observed, reflected in a smaller than expected number of uniparental disomic embryos; (4) nondisjunction events did not seem to occur at random throughout the 76 mouse litters, but were clustered into fewer than would be expected cy chance; and (5) a deficiency of paternal chromosome 18 uniparental disomic embryos was observed along with a higher than normal rate of developmental retardation at 8.5 days post coitum, raising the possibility that this chromosome has at least one imprinted gene.

scholarly journals The H19 Differentially Methylated Region Marks the Parental Origin of a Heterologous Locus without Gametic DNA Methylation

2004 ◽  
Vol 24 (9) ◽  
pp. 3588-3595 ◽  
Author(s):  
Kye-Yoon Park ◽  
Elizabeth A. Sellars ◽  
Alexander Grinberg ◽  
Sing-Ping Huang ◽  
Karl Pfeifer
Keyword(s):  
Dna Methylation ◽  
Mouse Chromosome ◽  
Germ Line ◽  
Transcriptional Silencing ◽  
Chromosome 7 ◽  
Differentially Methylated Region ◽  
Parental Origin ◽  
Imprinted Genes ◽  
Chromosome 5 ◽  
The Third

ABSTRACT Igf2 and H19 are coordinately regulated imprinted genes physically linked on the distal end of mouse chromosome 7. Genetic analyses demonstrate that the differentially methylated region (DMR) upstream of the H19 gene is necessary for three distinct functions: transcriptional insulation of the maternal Igf2 allele, transcriptional silencing of paternal H19 allele, and marking of the parental origin of the two chromosomes. To test the sufficiency of the DMR for the third function, we inserted DMR at two heterologous positions in the genome, downstream of H19 and at the alpha-fetoprotein locus on chromosome 5. Our results demonstrate that the DMR alone is sufficient to act as a mark of parental origin. Moreover, this activity is not dependent on germ line differences in DMR methylation. Thus, the DMR can mark its parental origin by a mechanism independent of its own DNA methylation.

scholarly journals Focusing on parental origin of aneuploidy: does paternal age impact aneuploidy rates in embryos?

2019 ◽  
Vol 112 (3) ◽  
pp. e16
Author(s):  
Katrina Merrion ◽  
Diane Ahern ◽  
Jessica Adsit ◽  
Katherine L. Howard ◽  
Dusan Kijacic ◽  
...  
Keyword(s):  
Paternal Age ◽  
Parental Origin

scholarly journals Prenatal diagnosis of a new case: De novo balanced non-Robertsonian translocation involving t(15;22)(p11.2;q11.2)

2018 ◽  
Vol 21 (2) ◽  
pp. 69-72
Author(s):  
Eİ Atli ◽  
H Gurkan ◽  
E Atli ◽  
H Tozkir ◽  
GF Varol ◽  
...  
Keyword(s):  
Robertsonian Translocation ◽  
De Novo ◽  
Chorionic Villus ◽  
Comparative Genomic ◽  
Chromosome 22 ◽  
Chromosome 15 ◽  
Unusual Event ◽  
First Case ◽  
Unusual Phenomenon ◽  
Acrocentric Chromosomes

Abstract The balanced non-Robertsonian translocation (ROB) associated with acrocentric chromosomes is an unusual phenomenon. We report the case of rare non-ROB involving chromosomes 15 and 22 with cytogenetic and molecular cytogenetic findings of 46,XY,t(15;22)(p11.2;q11.2). To the best of our knowledge, t(15;22) is the first report of this breakpoint that is not the usual non-ROB. The karyotype of the chorionic villus cell was 46,XY,t(15;22)(p11.2; q11.2) from two different initial cultures. This is different from the usual non-ROB of acrocentric chromosomes. Comparative genomic hybridization has been performed to determine the chromosomal origin. Non-Robertsonian translocation associated with acrocentric chromosomes is an unusual event and only a few cases have been reported. In this study, we observed acrocentric chromosomes 15 and 22 as a rarely balanced non-ROB, where satellites of chromosome 15 translocated to chromosome 22 and part of chromosome 22 were translocated to chromosome 15. To the best of our knowledge, our patient is the first case reported in the literature for this translocation in prenatal and postnatal periods.

6;7 chromosomal translocation in spontaneously arising rat immunocytomas: evidence for c-myc breakpoint clustering and correlation between isotypic expression and the c-myc target

1988 ◽  
Vol 8 (1) ◽  
pp. 441-451
Author(s):  
W S Pear ◽  
G Wahlström ◽  
S F Nelson ◽  
H Axelson ◽  
A Szeles ◽  
...  
Keyword(s):  
Molecular Analysis ◽  
Strong Correlation ◽  
Chromosomal Translocation ◽  
Burkitt’S Lymphoma ◽  
Burkitt's Lymphoma ◽  
Chromosome 7 ◽  
Chromosome 6 ◽  
Intron 1 ◽  
Switch Regions ◽  
Exon 1

Our previous studies have shown that spontaneously arising immunocytomas in the LOU/Ws1 strain of rats contain a t(6;7) chromosomal translocation in all seven tumors studied (F. M. Babonits, J. Spira, G. Klein, and H. Bazin, Int. J. Cancer 29:431-437, 1982). We have also shown that the c-myc is located on chromosome 7 (J. Sümegi, J. Spira, H. Bazin, J. Szpirer, G. Levan, and G. Klein, Nature (London) 306:497-499, 1983) and the immunoglobulin H cluster on chromosome 6 (W.S. Pear, G. Wahlström, J. Szpirer, G. Levan, G. Klein, and J. Sümegi, Immunogenetics 23:393-395, 1986). We now report a detailed cytogenetic and molecular analysis of nine additional rat immunocytomas. The t(6;7) chromosomal translocation is found in all tumors. Mapping of the c-myc breakpoints showed that in 10 of 14 tumors, the c-myc breakpoints are clustered in a 1.5-kilobase region upstream of exon 1. In contrast with sporadic Burkitt's lymphoma and mouse plasmacytoma, only 1 of 14 tumors contains the c-myc breakpoints in either exon 1 or intron 1. Analysis of the sequences juxtaposed to the c-myc show that immunoglobulin H switch regions are the targets in at least five tumors and that there is a strong correlation between the secreted immunoglobulin and the c-myc target. Unlike sporadic Burkitt's lymphoma and mouse plasmacytoma, at least two rat immunocytomas show recombination of the c-myc with sequences distinct from immunoglobulin switch regions.

The inheritance of germline-specific epigenetic modifications during development

1993 ◽  
Vol 339 (1288) ◽  
pp. 165-172 ◽  
Keyword(s):  
Mouse Chromosome ◽  
Germ Line ◽  
Epigenetic Modification ◽  
Embryonic Stem ◽  
Epigenetic Inheritance ◽  
Epigenetic Modifications ◽  
Chromosome 7 ◽  
Parental Origin ◽  
Imprinted Genes ◽  
Female Germline

Parental genomes in mammals are programmed in the germline with heritable epigenetic modifications that exert control on the expression of specific (imprinted) genes. DNA methylation is one form of epigenetic modification which shows marked genome-wide variations in the germline and during early development. Certain transgene loci also demonstrate (reversible) germline-specific methylation imprints that are heritable in somatic tissues during development. Recently, four endogenous genes have been identified whose expression is dependent on their parental origin. The mechanism of genomic imprinting and the role of imprinted genes during development is beginning to be analysed. Three of these genes map to the mouse chromosome 7. Human chromosomes 11p13, 11p15, and 15ql 1-13 are associated with disorders exhibiting parental origin effects in their patterns of inheritance. These regions share syntenic homology with mouse chromosome 7. The relationship between parental imprints, germ line-dependent epigenetic inheritance and totipotency is also under investigation using embryonic stem cells derived from the epiblast. These cells are pluripotent or totipotent and evidence indicates the presence of at least the primary parental imprints. However, imprints inherited from the paternal germline in androgenetic cells are apparently more stable than those from the female germline in parthenogenetic cells.

scholarly journals 6;7 chromosomal translocation in spontaneously arising rat immunocytomas: evidence for c-myc breakpoint clustering and correlation between isotypic expression and the c-myc target.

1988 ◽  
Vol 8 (1) ◽  
pp. 441-451 ◽  
Author(s):  
W S Pear ◽  
G Wahlström ◽  
S F Nelson ◽  
H Axelson ◽  
A Szeles ◽  
...  
Keyword(s):  
Molecular Analysis ◽  
Strong Correlation ◽  
Chromosomal Translocation ◽  
Burkitt’S Lymphoma ◽  
Burkitt's Lymphoma ◽  
Chromosome 7 ◽  
Chromosome 6 ◽  
Intron 1 ◽  
Switch Regions ◽  
Exon 1

Our previous studies have shown that spontaneously arising immunocytomas in the LOU/Ws1 strain of rats contain a t(6;7) chromosomal translocation in all seven tumors studied (F. M. Babonits, J. Spira, G. Klein, and H. Bazin, Int. J. Cancer 29:431-437, 1982). We have also shown that the c-myc is located on chromosome 7 (J. Sümegi, J. Spira, H. Bazin, J. Szpirer, G. Levan, and G. Klein, Nature (London) 306:497-499, 1983) and the immunoglobulin H cluster on chromosome 6 (W.S. Pear, G. Wahlström, J. Szpirer, G. Levan, G. Klein, and J. Sümegi, Immunogenetics 23:393-395, 1986). We now report a detailed cytogenetic and molecular analysis of nine additional rat immunocytomas. The t(6;7) chromosomal translocation is found in all tumors. Mapping of the c-myc breakpoints showed that in 10 of 14 tumors, the c-myc breakpoints are clustered in a 1.5-kilobase region upstream of exon 1. In contrast with sporadic Burkitt's lymphoma and mouse plasmacytoma, only 1 of 14 tumors contains the c-myc breakpoints in either exon 1 or intron 1. Analysis of the sequences juxtaposed to the c-myc show that immunoglobulin H switch regions are the targets in at least five tumors and that there is a strong correlation between the secreted immunoglobulin and the c-myc target. Unlike sporadic Burkitt's lymphoma and mouse plasmacytoma, at least two rat immunocytomas show recombination of the c-myc with sequences distinct from immunoglobulin switch regions.

scholarly journals Mechanism of imprinting on mouse distal chromosome 7

1998 ◽  
Vol 72 (3) ◽  
pp. 237-245 ◽  
Author(s):  
JUSTIN F-X. AINSCOUGH ◽  
ROSALIND M. JOHN ◽  
M. AZIM SURANI
Keyword(s):  
Chromosome 7 ◽  
Parental Origin ◽  
Imprinted Genes ◽  
Critical Feature ◽  
Male Germline ◽  
Domain Type ◽  
Distal Chromosome ◽  
Type Mode ◽  
Single Allele ◽  
Female Germline

Genomic imprinting is an epigenetic mode of gene regulation that results in expression of the autosomal ‘imprinted’ genes from only a single allele, determined exclusively by parental origin. To date over 20 imprinted genes have been identified in mouse and man and these appear to lie in clusters in restricted regions on a subset of chromosomes. This may be a critical feature of imprinting suggesting a domain-type mode of regulation. Imprinted domains are replicated asynchronously, show sex-specific meiotic recombination frequencies and have CpG-rich regions that are differentially methylated, often associated with the imprinted genes themselves. Mouse distal chromosome 7 is one such domain, containing at least nine imprinted genes spanning over 1 Mb of DNA. For the maternally expressed p57Kip2 gene, passage through the female germline is essential to generate the active state, whereas passage through the male germline is needed to force the maternally expressed H19 gene into an inactive state. It is therefore possible that the mouse distal chromosome 7 imprinted domain is actually composed of two or more independently regulated subdomains.

A balanced reciprocal translocation t(5;7)(q14;q32) associated with autistic disorder: Molecular analysis of the chromosome 7 breakpoint

2001 ◽  
Vol 105 (8) ◽  
pp. 729-736 ◽  
Author(s):  
Dmitry Tentler ◽  
Göran Brandberg ◽  
Catalina Betancur ◽  
Christopher Gillberg ◽  
Göran Annerén ◽  
...  
Keyword(s):  
Molecular Analysis ◽  
Autistic Disorder ◽  
Reciprocal Translocation ◽  
Chromosome 7
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