The paper I am going to share today collected my attention because it merges two fundamental topics that are quite a lot undertaken in evolutionary biology: plant genomics and the rule of cis-regulatory elements in evolution. Plant biology provides an excellent framework to perform studies in genomic evolution. Even if the knowledge acquired is applied mostly in agricultural biotechnology, that is a field that trills me a lot, plants represent a perfect environment to understand general- validity principles in genomic evolution. The role of cis- regulatory elements, and their contribution to organism differentiation, are generally understood to be very relevant, but I sense that this topic is quite neglected and a bit obscure.
Modification of cis regulatory elements to produce differences in gene expression level, localization, and timing is an important mechanism by which organisms evolve divergent adaptations. (Lemmon et al., Plos Genetics, 2014)
That is why I have particularly enjoyed the reading of this brand new paper, authored by Zachary H. Lemmon and co-workers, and developed in a collaboration between the University of Wisconsin and Ithaca University (NY). In plant biology, one of the main points of interest is obviously the process of domestication, and its analysis under a molecular point of view. In this paper, maize domestication is analyzed by a genomic comparison among domesticated and non domesticated species within the Zea genus.
To examine the differences in gene regulation during maize domestication from its wild progenitor, teosinte, an allele specific expression analysis is performed on pure lineages and hybrids in different trans and cis regulatory regimes. The investigation focuses on three tissues (ear, leaf and stem) from different developmental stages. RNA-seq analysis provide the confirmation of the consistent cis regulatory divergence in genes that are significantly correlated with the ones under selection during domestication and crop improvement. This suggests the important role for cis regulatory elements in maize evolution.
As the authors argue the relevance of this result for plant biology, we can understand that this study highlights the importance of regulatory genome in evolution, and the great potential that plant biology have as framework for evolutionary biology.