|Title||Transcription regulation and animal diversity.|
|Publication Type||Journal Article|
|Year of Publication||2003|
|Authors||Levine, M, Tjian, R|
|Date Published||2003 Jul 10|
|Keywords||Animals, Chromatin, DNA, Ecosystem, Gene Expression Regulation, Humans, Regulatory Sequences, Nucleic Acid, Transcription Factors, Transcription, Genetic|
Whole-genome sequence assemblies are now available for seven different animals, including nematode worms, mice and humans. Comparative genome analyses reveal a surprising constancy in genetic content: vertebrate genomes have only about twice the number of genes that invertebrate genomes have, and the increase is primarily due to the duplication of existing genes rather than the invention of new ones. How, then, has evolutionary diversity arisen? Emerging evidence suggests that organismal complexity arises from progressively more elaborate regulation of gene expression.