PT  - JOURNAL ARTICLE
AU  - Michael Kuhn
AU  - Andreas Beyer
TI  - Conservation of expression regulation throughout the animal kingdom
AID  - 10.1101/007252
DP  - 2014 Jan 01
TA  - bioRxiv
PG  - 007252
4099  - http://biorxiv.org/content/early/2014/07/18/007252.short
4100  - http://biorxiv.org/content/early/2014/07/18/007252.full
AB  - Gene expression is often studied in the context of perturbations such as gene knockdown or drug treatment. In most cases, the response of the organism to such perturbation is not under evolutionary selection and the outcomes are therefore largely accidental. In contrast, gene expression changes during development and tissue formation are under strong selection. Here, we present the first cross-species mapping of tissue-specific and developmental gene expression patterns across a wide range of animals, including many non-model species. In our survey of 32 datasets across 23 species, we detected conserved expression programs on all taxonomic levels, both within animals and between the animals and their closest unicellular relatives, the choanoflagellates. We found that the rate of change in tissue expression patterns is a property of gene families. Subsequently, we used the conservation of expression programs as a means to identify neofunctionalization of gene duplication products. We found 1206 duplication events where one of the two genes kept the expression program of the original gene, whereas the other copy adopted a novel expression program. We corroborated such potential neofunctionalizations using independent network information: the duplication product with the more conserved expression pattern shared more interaction partners with the non-duplicated reference gene than the more diverging duplication product. Our findings open new avenues of study for the comparison and transfer of knowledge between different species.