scholarly journals Multiple Imprinted Genes Associated with Prader-Willi Syndrome and Location of an Imprinting Control Element

1996 ◽  
Vol 45 (1-2) ◽  
pp. 87-89
Author(s):  
R.D. Nicholls ◽  
M.T.C. Jong ◽  
C.C. Glenn ◽  
J. Gabriel ◽  
P.K. Rogan ◽  
...  
Keyword(s):  
Genomic Imprinting ◽  
Epigenetic Modification ◽  
Uniparental Disomy ◽  
Paternal Allele ◽  
Control Element ◽  
Parental Origin ◽  
Imprinted Genes ◽  
Mammalian Development ◽  
Specific Expression ◽  
Large Deletions

Our studies aim to identify the mechanisms and genes involved in genomic imprinting in mammalian development and human disease. Imprinting refers to an epigenetic modification of DNA that results in parent-of-origin specific expression during embryogenesis and in the adult. This imprint is reset at each generation, depending on the sex of the parental gametogenesis. Prader-Willi (PWS) and Angelman (AS) syndromes are excellent models for the study of genomic imprinting in humans, since these distinct neurobehavioural disorders are both associated with genetic abnormalities (large deletions, uniparental disomy, and imprinting mutations) of inheritance in chromosome 15q11-q13, dependent on the parental origin (reviewed in ref. 1). Some AS patients have biparental inheritance, consistent with a single imprinted gene (active on the maternal chromosome), whereas similar PWS patients are not found suggesting that at least two imprinted genes (active on the paternal allele) may be necessary for classical PWS. We have previously shown that the small ribonucleoprotein associated protein SmN gene (SNRPN), located in the PWS critical region [2], is only expressed from the paternal allele and is differentially methylated on parental alleles [3]. Therefore, SNRPN may have a role in PWS. Methylation imprints have also been found at two other loci in 15q11-q13, PW71 [4] and D15S9 [5], which map 120 kb and 1.5 Mb proximal to SNRPN, respectively. We have now characterized in detail the gene structure and expression from two imprinted loci within 15q11-q13, SNRPN and D15S9, which suggests that both loci are surprisingly complex, with important implications for the pathogenesis of PWS.

scholarly journals Basics and disturbances of genomic imprinting

2020 ◽  
Vol 32 (4) ◽  
pp. 297-304
Author(s):  
Dirk Prawitt ◽  
Thomas Haaf
Keyword(s):  
Genomic Imprinting ◽  
Primordial Germ Cells ◽  
Uniparental Disomy ◽  
Point Mutations ◽  
Paternal Allele ◽  
Imprinted Genes ◽  
Specific Expression ◽  
Imprinting Disorders ◽  
Increased Risk ◽  
Genomic Imprints

Abstract Genomic imprinting ensures the parent-specific expression of either the maternal or the paternal allele, by different epigenetic processes (DNA methylation and histone modifications) that confer parent-specific marks (imprints) in the paternal and maternal germline, respectively. Most protein-coding imprinted genes are involved in embryonic growth, development, and behavior. They are usually organized in genomic domains that are regulated by differentially methylated regions (DMRs). Genomic imprints are erased in the primordial germ cells and then reset in a gene-specific manner according to the sex of the germline. The imprinted genes regulate and interact with other genes, consistent with the existence of an imprinted gene network. Defects of genomic imprinting result in syndromal imprinting disorders. To date a dozen congenital imprinting disorders are known. Usually, a given imprinting disorder can be caused by different types of defects, including point mutations, deletions/duplications, uniparental disomy, and epimutations. Causative trans-acting factors in imprinting disorders, including ZFP57 and the subcortical maternal complex (SCMC), have the potential to affect multiple DMRs across the genome, resulting in a multi-locus imprinting disturbance. There is evidence that mutations in components of the SCMC can confer an increased risk for imprinting disorders.

Erasing genomic imprinting memory in mouse clone embryos produced from day 11.5 primordial germ cells

Development ◽  
2002 ◽  
Vol 129 (8) ◽  
pp. 1807-1817 ◽  
Author(s):  
Jiyoung Lee ◽  
Kimiko Inoue ◽  
Ryuichi Ono ◽  
Narumi Ogonuki ◽  
Takashi Kohda ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Genomic Imprinting ◽  
Nuclear Transfer ◽  
Monoallelic Expression ◽  
Parental Origin ◽  
Imprinted Genes ◽  
Specific Expression ◽  
Male And Female ◽  
Imprinted Gene ◽  
Methylation Patterns

Genomic imprinting is an epigenetic mechanism that causes functional differences between paternal and maternal genomes, and plays an essential role in mammalian development. Stage-specific changes in the DNA methylation patterns of imprinted genes suggest that their imprints are erased some time during the primordial germ cell (PGC) stage, before their gametic patterns are re-established during gametogenesis according to the sex of individuals. To define the exact timing and pattern of the erasure process, we have analyzed parental-origin-specific expression of imprinted genes and DNA methylation patterns of differentially methylated regions (DMRs) in embryos, each derived from a single day 11.5 to day 13.5 PGC by nuclear transfer. Cloned embryos produced from day 12.5 to day 13.5 PGCs showed growth retardation and early embryonic lethality around day 9.5. Imprinted genes lost their parental-origin-specific expression patterns completely and became biallelic or silenced. We confirmed that clones derived from both male and female PGCs gave the same result, demonstrating the existence of a common default state of genomic imprinting to male and female germlines. When we produced clone embryos from day 11.5 PGCs, their development was significantly improved, allowing them to survive until at least the day 11.5 embryonic stage. Interestingly, several intermediate states of genomic imprinting between somatic cell states and the default states were seen in these embryos. Loss of the monoallelic expression of imprinted genes proceeded in a step-wise manner coordinated specifically for each imprinted gene. DNA demethylation of the DMRs of the imprinted genes in exact accordance with the loss of their imprinted monoallelic expression was also observed. Analysis of DNA methylation in day 10.5 to day 12.5 PGCs demonstrated that PGC clones represented the DNA methylation status of donor PGCs well. These findings provide strong evidence that the erasure process of genomic imprinting memory proceeds in the day 10.5 to day 11.5 PGCs, with the timing precisely controlled for each imprinted gene. The nuclear transfer technique enabled us to analyze the imprinting status of each PGC and clearly demonstrated a close relationship between expression and DNA methylation patterns and the ability of imprinted genes to support development.

Parental Imprinting on Mouse Chromosome 7

1996 ◽  
Vol 45 (1-2) ◽  
pp. 41-41
Author(s):  
A.C. Ferguson-Smith
Keyword(s):  
Mouse Chromosome ◽  
Uniparental Disomy ◽  
Chromosome 7 ◽  
Paternal Allele ◽  
Parental Origin ◽  
Imprinted Genes ◽  
Clear Cut ◽  
Parental Imprinting ◽  
H19 Gene ◽  
Mutant Phenotypes

Genetic studies have shown that both a maternally and paternally inherited copy of mouse chromosome 7 are essential for normal embryogenesis. When the parental dosage is altered, such as in maternal or paternal uniparental disomy for chromosome 7 (UPD7), the resulting embryos die. This is due to the altered dosage of imprinted genes which are normally expressed only from the paternally or maternally inherited chromosome homologue. Several genes on mouse chromosome 7 are subject to parental imprinting. Mutant phenotypes seen in UPD7 embryos and chimaeras can be explained by the altered dosage of some of these genes.The mechanism(s) that causes genes to be expressed in a parental origin specific manner has not yet been determined but is believed to involve germline specific modifications to DNA and/or chromatin which are acted upon after fertilisation to affect the activity of imprinted genes. Two genes, H19 and Igf2, are located 90kb apart on the distal end of chromosome 7 and are imprinted reciprocally with the maternally inherited allele of HI9 and paternally inherited allele of Igf2 being expressed. We have used UPD7 embryos to identify epigenetic modifications that distinguish the two parental alleles in the H19 and Igf2 domain by comparing DNA and chromatin from normal and maternal UPD cobceptuses. Clear cut differences in DNA methylation and chromatin compaction were observed for the H19 gene with the paternal allele exhibiting promoter methylation and nuclease insensitivity. These were not found in sperm. In addition, no major differences were noted for the Igf2 gene, although subtle parental origin specific modifications were found. These studies suggest that the two genes may share a common regulatory mechanism which controls their reciprocal imprinting.

scholarly journals Genomic imprinting and its role in ethiology of human hereditary diseases

2004 ◽  
Vol 3 (3) ◽  
pp. 8-17
Author(s):  
S. A. Nazarenko
Keyword(s):  
Gene Expression ◽  
Genomic Imprinting ◽  
Special Class ◽  
Growth And Development ◽  
Epigenetic Inheritance ◽  
Hereditary Diseases ◽  
Parental Origin ◽  
Imprinted Genes ◽  
Methylation Of Dna ◽  
Differential Gene

Genomic imprinting is a form of non-Mendelian epigenetic inheritance that is defined by differential gene expression depending on its parental origin — maternal or paternal. It is known about 60 imprinted genes many of which effect significantly on the fetus growth and development. Methylation of DNA cytosine bases that defines the interaction of DNA and proteins identifying the modified bases and controls the gene expression through chromatin compacting-decompacting mechanism, is a main epigenetic genom modifier. Disturbances in monoallelic gene expression lead to the development of a special class of human hereditary diseases — genomic imprinting diseases.

Imprinting of insulin-like growth factor 2 is modulated during hematopoiesis

Blood ◽  
2000 ◽  
Vol 96 (9) ◽  
pp. 3023-3028 ◽  
Author(s):  
Ian M. Morison ◽  
Michael R. Eccles ◽  
Anthony E. Reeve
Keyword(s):  
Growth Factor ◽  
Mononuclear Cells ◽  
Model Systems ◽  
Paternal Allele ◽  
Parental Origin ◽  
Insulin Like Growth Factor ◽  
Specific Expression ◽  
Peripheral Blood Mononuclear ◽  
Multistep Process

The transcription of insulin-like growth factor 2 (IGF-2) is affected by genomic imprinting, a multistep process through which the parental origin of a gene influences its transcription. The maternal copy of IGF-2 is silenced in most human tissues, but in the choroid plexus and the adult liver both alleles of IGF-2 are expressed. This study shows that though in peripheral blood mononuclear cells IGF-2shows paternal allele-specific expression, in total bone marrow both alleles are transcribed. This modulation of imprinting is not attributable to use of the P1 promoter, because transcription from the P3 promoter occurred from both alleles. These results suggest that transcriptional recognition of the IGF-2 imprint can be modulated during hematopoiesis and may facilitate the development of in vitro model systems to study the transcriptional recognition of a genomic imprint.

scholarly journals Epigenetic Mechanisms of Genomic Imprinting: Common Themes in the Regulation of Imprinted Regions in Mammals, Plants, and Insects

2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
William A. MacDonald
Keyword(s):  
Genomic Imprinting ◽  
Chromosomal Region ◽  
Epigenetic Inheritance ◽  
Imprinted Genes ◽  
Epigenetic Mechanisms ◽  
Research Model ◽  
Primary Research ◽  
Specific Expression ◽  
Broad Variety ◽  
Control Regions

Genomic imprinting is a form of epigenetic inheritance whereby the regulation of a gene or chromosomal region is dependent on the sex of the transmitting parent. During gametogenesis, imprinted regions of DNA are differentially marked in accordance to the sex of the parent, resulting in parent-specific expression. While mice are the primary research model used to study genomic imprinting, imprinted regions have been described in a broad variety of organisms, including other mammals, plants, and insects. Each of these organisms employs multiple, interrelated, epigenetic mechanisms to maintain parent-specific expression. While imprinted genes and imprint control regions are often species and locus-specific, the same suites of epigenetic mechanisms are often used to achieve imprinted expression. This review examines some examples of the epigenetic mechanisms responsible for genomic imprinting in mammals, plants, and insects.

Genomic imprinting, development and disease—is pre-eclampsia caused by a maternally imprinted gene?

1998 ◽  
Vol 10 (1) ◽  
pp. 23 ◽  
Author(s):  
Jennifer A. Marshall Graves
Keyword(s):  
Genomic Imprinting ◽  
Fetal Development ◽  
Mutant Gene ◽  
The Other ◽  
Paternal Allele ◽  
Imprinted Genes ◽  
Maternal Expression ◽  
Mutant Genes ◽  
Normal Placenta ◽  
Mode Of Inheritance

Several genes in conserved clusters are expressed from only the maternal or the paternal allele. The other allele has been genetically silenced (‘imprinted’) by its passage through one sex. Many known imprinted genes have effects on embryonic or trophoblast growth or fetal development, and mutation or loss of the single active copy causes diseases such as Prader–Willi, Angelmann and Beckwith–Wiederman syndromes. Imprinted genes show an unusual mode of inheritance, since mutant genes have an effect on the phenotype only if they come from the parent from which they are expressed. This may explain some conditions which appear to be heritable but show an inconsistant pattern in affected families. Of particular interest is pre-eclampsia/eclampsia, the most serious complication of pregnancy, which has some features suggesting that it results from fetal expression of the mutant gene, but others which imply it results from maternal expression. This could be resolved by proposing that the condition is due to mutation in a paternally imprinted, maternally active gene which must be expressed by the fetus in order to establish a normal placenta in the first pregnancy.

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.

Multilocus methylation defects in imprinting disorders

2015 ◽  
Vol 6 (1) ◽  
pp. 47-57 ◽  
Author(s):  
Deborah J.G. Mackay ◽  
Thomas Eggermann ◽  
Karin Buiting ◽  
Intza Garin ◽  
Irène Netchine ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Normal Development ◽  
Genetic Diseases ◽  
Parental Origin ◽  
Imprinted Genes ◽  
Mammalian Development ◽  
Imprinting Disorders ◽  
Common Process ◽  
Genetic Mechanisms ◽  
Methylation Defects

AbstractMammals inherit two complete sets of chromosomes, one from the father and one from the mother, and most autosomal genes are expressed from both maternal and paternal alleles. In imprinted genes, the expression of the allele is dependent upon its parental origin. Appropriate regulation of imprinted genes is important for normal development, with several genetic diseases associated with imprinting defects. A common process for controlling gene activity is methylation. The first steps for understanding the functions of DNA methylation and its regulation in mammalian development have led us to identify common (epi)genetic mechanisms involved in the eight human congenital imprinting disorders.

scholarly journals Chromosomal rearrangements in the 11p15 imprinted region: 17 new 11p15.5 duplications with associated phenotypes and putative functional consequences

2017 ◽  
Vol 55 (3) ◽  
pp. 205-213 ◽  
Author(s):  
Solveig Heide ◽  
Sandra Chantot-Bastaraud ◽  
Boris Keren ◽  
Madeleine D Harbison ◽  
Salah Azzi ◽  
...  
Keyword(s):  
De Novo ◽  
Chromosomal Rearrangements ◽  
Paternal Allele ◽  
Parental Origin ◽  
Imprinted Genes ◽  
Phenotype Correlation ◽  
Growth Disturbance ◽  
Correlation Studies ◽  
Functional Consequences

BackgroundThe 11p15 region contains two clusters of imprinted genes. Opposite genetic and epigenetic anomalies of this region result in two distinct growth disturbance syndromes: Beckwith-Wiedemann (BWS) and Silver-Russell syndromes (SRS). Cytogenetic rearrangements within this region represent less than 3% of SRS and BWS cases. Among these, 11p15 duplications were infrequently reported and interpretation of their pathogenic effects is complex.ObjectivesTo report cytogenetic and methylation analyses in a cohort of patients with SRS/BWS carrying 11p15 duplications and establish genotype/phenotype correlations.MethodsFrom a cohort of patients with SRS/BWS with an abnormal methylation profile (using ASMM-RTQ-PCR), we used SNP-arrays to identify and map the 11p15 duplications. We report 19 new patients with SRS (n=9) and BWS (n=10) carrying de novo or familial 11p15 duplications, which completely or partially span either both telomeric and centromeric domains or only one domain.ResultsLarge duplications involving one complete domain or both domains are associated with either SRS or BWS, depending on the parental origin of the duplication. Genotype-phenotype correlation studies of partial duplications within the telomeric domain demonstrate the prominent role of IGF2, rather than H19, in the control of growth. Furthermore, it highlights the role of CDKN1C within the centromeric domain and suggests that the expected overexpression of KCNQ1OT1 from the paternal allele (in partial paternal duplications, excluding CDKN1C) does not affect the expression of CDKN1C.ConclusionsThe phenotype associated with 11p15 duplications depends on the size, genetic content, parental inheritance and imprinting status. Identification of these rare duplications is crucial for genetic counselling.

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