Life Sciences Research for Lifelong Health

Gavin Kelsey

Research Summary

As well as genetic information, the egg and sperm also contribute epigenetic annotations that may influence gene activity after fertilisation. These annotations may be direct modifications of the DNA bases or of the proteins around which the DNA is wrapped into chromatin. Our goal is to understand whether, through epigenetics, factors such as a mother’s age or diet have consequences on the health of a child.
 
We examine how epigenetic states are set up in oocytes – or egg cells – and influence gene expression in the embryo. For example, repressive chromatin marks in oocytes lead to long-term silencing of genes inherited from the mother, particularly in cells that will form the placenta. We are also interested in how variations in DNA methylation come about in oocytes and whether we can use this variation as a marker for oocyte quality and embryo potential. To investigate these questions, we develop methods to profile epigenetic information in very small numbers of cells or even in single cells.

Latest Publications

A DNMT3A PWWP mutation leads to methylation of bivalent chromatin and growth retardation in mice.
Sendžikaitė G, Hanna CW, Stewart-Morgan KR, Ivanova E, Kelsey G

DNA methyltransferases (DNMTs) deposit DNA methylation, which regulates gene expression and is essential for mammalian development. Histone post-translational modifications modulate the recruitment and activity of DNMTs. The PWWP domains of DNMT3A and DNMT3B are posited to interact with histone 3 lysine 36 trimethylation (H3K36me3); however, the functionality of this interaction for DNMT3A remains untested in vivo. Here we present a mouse model carrying a D329A point mutation in the DNMT3A PWWP domain. The mutation causes dominant postnatal growth retardation. At the molecular level, it results in progressive DNA hypermethylation across domains marked by H3K27me3 and bivalent chromatin, and de-repression of developmental regulatory genes in adult hypothalamus. Evaluation of non-CpG methylation, a marker of de novo methylation, further demonstrates the altered recruitment and activity of DNMT3A at bivalent domains. This work provides key molecular insights into the function of the DNMT3A-PWWP domain and role of DNMT3A in regulating postnatal growth.

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Nature communications, 10, 2041-1723, 1884, 2019

PMID: 31015495

Genomic Imprinting and Physiological Processes in Mammals.
Tucci V, Isles AR, Kelsey G, Ferguson-Smith AC,

Complex multicellular organisms, such as mammals, express two complete sets of chromosomes per nucleus, combining the genetic material of both parents. However, epigenetic studies have demonstrated violations to this rule that are necessary for mammalian physiology; the most notable parental allele expression phenomenon is genomic imprinting. With the identification of endogenous imprinted genes, genomic imprinting became well-established as an epigenetic mechanism in which the expression pattern of a parental allele influences phenotypic expression. The expanding study of genomic imprinting is revealing a significant impact on brain functions and associated diseases. Here, we review key milestones in the field of imprinting and discuss mechanisms and systems in which imprinted genes exert a significant role.

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Cell, 176, 1097-4172, 952-965, 2019

PMID: 30794780

Genome-Scale Oscillations in DNA Methylation during Exit from Pluripotency.
Rulands S, Lee HJ, Clark SJ, Angermueller C, Smallwood SA, Krueger F, Mohammed H, Dean W, Nichols J, Rugg-Gunn P, Kelsey G, Stegle O, Simons BD, Reik W

Pluripotency is accompanied by the erasure of parental epigenetic memory, with naïve pluripotent cells exhibiting global DNA hypomethylation both in vitro and in vivo. Exit from pluripotency and priming for differentiation into somatic lineages is associated with genome-wide de novo DNA methylation. We show that during this phase, co-expression of enzymes required for DNA methylation turnover, DNMT3s and TETs, promotes cell-to-cell variability in this epigenetic mark. Using a combination of single-cell sequencing and quantitative biophysical modeling, we show that this variability is associated with coherent, genome-scale oscillations in DNA methylation with an amplitude dependent on CpG density. Analysis of parallel single-cell transcriptional and epigenetic profiling provides evidence for oscillatory dynamics both in vitro and in vivo. These observations provide insights into the emergence of epigenetic heterogeneity during early embryo development, indicating that dynamic changes in DNA methylation might influence early cell fate decisions.

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Cell systems, , 2405-4712, , 2018

PMID: 30031774

Group Members

Latest Publications

A DNMT3A PWWP mutation leads to methylation of bivalent chromatin and growth retardation in mice.

Sendžikaitė G, Hanna CW, Stewart-Morgan KR

Nature communications
10 2041-1723:1884 (2019)

PMID: 31015495

Genomic Imprinting and Physiological Processes in Mammals.

Tucci V, Isles AR, Kelsey G

Cell
176 1097-4172:952-965 (2019)

PMID: 30794780

Genome-Scale Oscillations in DNA Methylation during Exit from Pluripotency.

Rulands S, Lee HJ, Clark SJ

Cell systems
2405-4712: (2018)

PMID: 30031774

Epigenetic regulation in development: is the mouse a good model for the human?

Hanna CW, Demond H, Kelsey G

Human reproduction update
1460-2369: (2018)

PMID: 29992283

scNMT-seq enables joint profiling of chromatin accessibility DNA methylation and transcription in single cells.

Clark SJ, Argelaguet R, Kapourani CA

Nature communications
9 2041-1723:781 (2018)

PMID: 29472610

MLL2 conveys transcription-independent H3K4 trimethylation in oocytes.

Hanna CW, Taudt A, Huang J

Nature structural & molecular biology
25 1545-9985:73-82 (2018)

PMID: 29323282

Cultured bovine embryo biopsy conserves methylation marks from original embryo.

Fonseca Balvís N, Garcia-Martinez S, Pérez-Cerezales S

Biology of reproduction
97 1529-7268:189-196 (2017)

PMID: 29044423

Single-cell epigenomics: Recording the past and predicting the future.

Kelsey G, Stegle O, Reik W

Science (New York, N.Y.)
358 1095-9203:69-75 (2017)

PMID: 28983045

DNA Methylation in Embryo Development: Epigenetic Impact of ART (Assisted Reproductive Technologies).

Canovas S, Ros.s PJ, Kelsey G

BioEssays : news and reviews in molecular, cellular and developmental biology
1521-1878: (2017)

PMID: 28940661

Genomic imprinting beyond DNA methylation: a role for maternal histones.

Hanna CW, Kelsey G

Genome biology
18 1474-760X:177 (2017)

PMID: 28927436

The histone 3 lysine 4 methyltransferase Setd1b is a maternal effect gene required for the oogenic gene expression program.

Brici D, Zhang Q, Reinhardt S

Development (Cambridge, England)
1477-9129: (2017)

PMID: 28619824

Transcription and chromatin determinants of de novo DNA methylation timing in oocytes.

Gahurova L, Tomizawa SI, Smallwood SA

Epigenetics & chromatin
10 1756-8935:25 (2017)

PMID: 28507606