Howard Cedar
Hebrew University of Jerusalem
Molecular biologyDNA methylationMethylationGeneticsBiology
What is this?
Publications 167
#1Tal Falick Michaeli (HUJI: Hebrew University of Jerusalem)H-Index: 2
#2Adam Spiro (HUJI: Hebrew University of Jerusalem)H-Index: 3
Last. Yuval Gielchinsky (HUJI: Hebrew University of Jerusalem)H-Index: 10
view all 9 authors...
: Gestational age determination by traditional tools (last menstrual period, ultrasonography measurements and Ballard Maturational Assessment in newborns) has major limitations and therefore there is a need to find different approaches. In this study, we looked for a molecular marker that can be used to determine the accurate gestational age of the newborn. To this end, we performed reduced representation bisulfite sequencing (RRBS) on 41 cord blood and matching placenta samples from women betwe...
1 CitationsSource
#1Razi Greenfield (HUJI: Hebrew University of Jerusalem)H-Index: 2
#2Amalia Tabib (HUJI: Hebrew University of Jerusalem)H-Index: 5
Last. Howard Cedar (HUJI: Hebrew University of Jerusalem)H-Index: 73
view all 7 authors...
Following erasure in the blastocyst, the entire genome undergoes de novo methylation at the time of implantation, with CpG islands being protected from this process. This bimodal pattern is then preserved throughout development and the lifetime of the organism. Using mouse embryonic stem cells as a model system, we demonstrate that the binding of an RNA polymerase complex on DNA before de novo methylation is predictive of it being protected from this modification, and tethering experiments demon...
2 CitationsSource
#1Yuval Dor (HUJI: Hebrew University of Jerusalem)H-Index: 49
#2Howard Cedar (HUJI: Hebrew University of Jerusalem)H-Index: 73
Summary DNA methylation represents an annotation system for marking the genetic text, thus providing instruction as to how and when to read the information and control transcription. Unlike sequence information, which is inherited, methylation patterns are established in a programmed process that continues throughout development, thus setting up stable gene expression profiles. This DNA methylation paradigm is a key player in medicine. Some changes in methylation closely correlate with age provi...
38 CitationsSource
#1Yitzhak Reizel (UPenn: University of Pennsylvania)H-Index: 3
#2Ofra Sabag (HUJI: Hebrew University of Jerusalem)H-Index: 7
Last. Howard Cedar (HUJI: Hebrew University of Jerusalem)H-Index: 73
view all 15 authors...
Development in mammals is accompanied by specific de novo and demethylation events that are thought to stabilize differentiated cell phenotypes. We demonstrate that a large percentage of the tissue-specific methylation pattern is generated postnatally. Demethylation in the liver is observed in thousands of enhancer-like sequences associated with genes that undergo activation during the first few weeks of life. Using. conditional gene ablation strategy we show that the removal of these methyl gro...
12 CitationsSource
#1Daniel Neiman (HUJI: Hebrew University of Jerusalem)H-Index: 6
#2Joshua Moss (HUJI: Hebrew University of Jerusalem)H-Index: 8
Last. Yuval Dor (HUJI: Hebrew University of Jerusalem)H-Index: 49
view all 11 authors...
DNA methylation at promoters is an important determinant of gene expression. Earlier studies suggested that the insulin gene promoter is uniquely unmethylated in insulin-expressing pancreatic β-cells, providing a classic example of this paradigm. Here we show that islet cells expressing insulin, glucagon, or somatostatin share a lack of methylation at the promoters of the insulin and glucagon genes. This is achieved by rapid demethylation of the insulin and glucagon gene promoters during differe...
9 CitationsSource
Asynchronous replication-timing patterns undergo programmed switching between maternal and paternal alleles in embryonic and adult stem cells.
4 CitationsSource
DNA methylation plays a prominent role in setting up and stabilizing the molecular design of gene regulation and by understanding this process one gains profound insight into the underlying biology of mammals. In this article, we trace the discoveries that provided the foundations of this field, starting with the mapping of methyl groups in the genome and the experiments that helped clarify how methylation patterns are maintained through cell division. We then address the basic relationship betw...
1 CitationsSource
Fragile X syndrome is the most frequent cause of inherited intellectual disability. The primary molecular defect in this disease is the expansion of a CGG repeat in the 5’ region of the fragile X mental retardation1 (FMR1) gene, leading to de novo methylation of the promoter and inactivation of this otherwise normal gene, but little is known about how these epigenetic changes occur during development. In order to gain insight into the nature of this process, we have used cell fusion technology t...
3 CitationsSource
#1Rena Levin-KleinH-Index: 5
#2Shira FraenkelH-Index: 4
Last. Yehudit BergmanH-Index: 37
view all 10 authors...
B cell development involves sequential rearrangement of the immunoglobulin chains, but fine control over the selection process remains a mystery. Here the authors show that individual alleles in pre-B cells are clonally unique and result from stochastic activation of V gene segments to induce optimal generation of a diverse repertoire.
5 CitationsSource
#1Michael Klutstein (HUJI: Hebrew University of Jerusalem)H-Index: 10
#2Joshua Moss (HUJI: Hebrew University of Jerusalem)H-Index: 8
Last. Howard Cedar (HUJI: Hebrew University of Jerusalem)H-Index: 73
view all 4 authors...
Recently, it was suggested that tissue variation in cancer risk originates from differences in the number of stem-cell divisions underlying each tissue, leading to different mutation loads. We show that this variation is also correlated with the degree of aberrant CpG island DNA methylation in normal cells. Methylation accumulates during aging in a subset of molecules, suggesting that the epigenetic landscape within a founder-cell population may contribute to tumor formation.
16 CitationsSource