The cistrome refers to “the set of cis-acting targets of a trans-acting factor on a genome-wide scale, also known as the in vivo genome-wide location of [transcription factor binding-sites] or histone modifications”. The term cistrome is a portmanteau of cistr (from cistron) + ome (from genome). The term cistrome was coined by investigators at the Dana-Farber Cancer Institute and Harvard Medical School.

Technologies such as chromatin immunoprecipitation combined with microarray analysis “ChIP-on-chip” or with massively parallel DNA sequencing “ChIP-Seq” have greatly facilitated the definition of the cistrome of transcription factors and other chromatin associated proteins.

The Regulatory Genome beautifully explains the control of animal development in terms of structure/function relations of inherited regulatory DNA sequence, and the emergent properties of the gene regulatory networks composed of these sequences.

The sequencing of the whole genome of multiple species provides us with the instruction book of how to build an organism and make it work, plus a detailed history of how diversity was generated during evolution. Unfortunately, we still understand only a small fraction, which is locating where genes are and deciphering the proteins they code for. The next step is to understand how the correct amount of gene products are produced in space and time to obtain a fully functioning organism, from the egg to the adult. This is what is known as the regulatory genome, a term coined by Eric H. Davidson.

References and Further Reading:

http://en.wikipedia.org/wiki/Cistrome

http://www.cistrome.org/Cistrome/Cistrome_Project.html

http://www.sciencemag.org/content/339/6123/1009.13.full

http://www.sciencedirect.com/science/book/9780120885633

http://www.ncbi.nlm.nih.gov/pubmed/19247937

http://www.ndsu.edu/pubweb/~mcclean/plsc731/cis-trans/cis-trans6.htm

(cis-acting elements and trans-acting factors)

http://en.wikipedia.org/wiki/Cis-regulatory_element

http://en.wikipedia.org/wiki/Trans-acting_factor

http://en.wikipedia.org/wiki/Trans-regulatory_element