Meeting Abstract
Phenotypic plasticity is a ubiquitous property of development, which itself has undergone a tremendous degree of evolutionary diversification. Even though most traits exhibit some degree of plasticity, and the developmental-genetic mechanisms underlying a subset of plastic traits are starting to be elucidated, how these mechanisms originated and diversified remains largely unclear. We used a comparative RNAseq approach on three species of Onthophagus beetles with varying degrees of nutrition sensitivity of horn growth to better understand the transcriptional basis and evolution of this plastic response. We compared one basal species, which exhibits a modest degree of nutrition responsiveness (O. gazella), with two derived species, one exhibiting extreme sensitivity (O. taurus) while the other has secondarily lost it (O. sagittarius). Using this approach, we seek to: 1) identify the gene repertoire whose expression is affected by nutritional variation within each species; 2) assess the extent to which nutrition-based plasticity in gene expression mirrors morphological plasticity within and across species; and 3) gain insight into the relative importance of genetic accommodation in gene expression plasticity and in the evolutionary diversification of nutrition-responsive development. More generally, we hope to better understand how patterns of gene expression underlying nutrition-responsive growth evolve in relation to the degree of morphological plasticity observed across closely related species. Given the growing attention on the role of genetic accommodation in diversification, understanding how gene expression underlying plastic traits itself evolves will be critical to better understand the mechanisms of genetic accommodation.
