Mapping the Epigenetic Landscape: Rediscovering Waddington in the Post-Genomic Age

JAMNICZKY H; BOUGHNER J; GONZALEZ P.; PARSONS T; POWELL C; ROLIAN C; SCHMIDT E; BOOKSTEIN F; HALLGRIMSSON B

Seattle

Congreso; SICB Annual Meeting 2010; 2010

<!-- /* Font Definitions */ @font-face {font-family:Helvetica; panose-1:2 11 6 4 2 2 2 2 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:536885895 0 0 0 511 0;} @font-face {font-family:"ヒラギノ角ゴ Pro W3"; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:auto; mso-font-signature:0 0 0 0 0 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-US; mso-fareast-language:EN-US;} p.FreeForm, li.FreeForm, div.FreeForm {mso-style-name:"Free Form"; mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; mso-bidi-font-size:10.0pt; font-family:Helvetica; mso-fareast-font-family:"ヒラギノ角ゴ Pro W3"; mso-bidi-font-family:"Times New Roman"; color:black; mso-ansi-language:EN-US; mso-fareast-language:#0400;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} -->             C.H. Waddington originally defined epigenetics as the causal analysis of development. This term has since come to connote the study of a variety of mechanisms and phenomena, many of which involve chromatin modification. We argue that Waddington’s original construal of the term was intended to describe emergent developmental phenomena above the level of the genome. Such epigenetic mechanisms often result in bias in the direction of generated organismal variation, or in modulation of the amount of such variation. Among others, emergent developmental phenomena generated by epigenetic mechanisms include modularity and canalization, and exist as part of the bridge between genotype and phenotype. These emergent phenomena are of particular interest in the study of the means by which different phenotypes arise. We therefore extend Waddington’s epigenetic landscape metaphor, which continues to provide useful explanatory power in the post-genomic age, to explore the generation of selectable variation at the organismal level. The study of epigenetics, as construed here, is a central disciplinary focus of evolutionary developmental biology.