Skip to main content Accessibility help
×
Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-27T13:14:43.324Z Has data issue: false hasContentIssue false

5 - Epigenetics, assisted reproductive technologies and growth restriction

Published online by Cambridge University Press:  05 February 2014

Jennifer M Frost
Affiliation:
University College London
Sayeda Abu-Amero
Affiliation:
University College London
Caroline Daelemans
Affiliation:
University College London
Gudrun E Moore
Affiliation:
University College London
Sean Kehoe
Affiliation:
John Radcliffe Hospital, Oxford
Lyn Chitty
Affiliation:
University College Hospital, London
Tessa Homfray
Affiliation:
St George’s University of London
Get access

Summary

Epigenetics: overview

Epigenetics is both heritable and a reversible interaction on the DNA, resulting in a change in expression or phenotype without altering the DNA sequence. Epigenetic effectors include the modification of DNA by methylation, the configuration and modification of nucleosomal histone proteins and the involvement of antisense RNA molecules. Epigenetics, in association with the transcriptional apparatus, regulates transcriptional profiles which dictate changes in cellular phenotype, controlling cell differentiation, division and death.

During mammalian development, a specific mechanism of epigenetic regulation is in place that acts on a small number of genes controlling some aspects of fetal growth and development and postnatal behaviour. This mechanism, known to involve approximately 100 genes in the mouse genome and 50 genes in the human genome, is characterised by parent-of-origin-specific monoallelic expression, and is known as genomic imprinting (see www.otago.ac.nz/IGC).

Genomic imprinting

Genomic imprinting was discovered in 1984 by pronuclear transfer experiments. Bipaternal and bimaternal embryos were created in parallel to reveal opposite lethal phenotypes. The genomes inherited from the mother and the father during sexual reproduction were found to be asymmetrical, and each indispensible in normal development (Figure 5.1).

Naturally occurring examples of these phenotypes can be found in humans and they are also incompatible with life. Ovarian teratomas are equivalent to gynogenotes and are characterised by varying stages of developing embryonic tissues, which are grossly disorganised. Hydatidiform moles are equivalent to androgenotes and take the form of overgrown and cystic trophoblast tissue, which can become highly invasive.

Type
Chapter
Information
Publisher: Cambridge University Press
Print publication year: 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Save book to Kindle

To save this book to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Available formats
×

Save book to Dropbox

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.

Available formats
×

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

Available formats
×