Cover image

mtDNA and nDNA (center, red and blue lines) show the exchange of information in the cell. Translucent arching shapes reach up and out, representing the dynamic movement of coexpression. The shapes on the left show prenatal activity and the shapes on the right represent higher levels of postnatal expression. A grid of squares emphasizes the species and organs involved, and the vertical curving lines depict the expanse of evolutionary time. In this issue, analysis of almost 1500 RNA-seq experiments from samples collected during embryonic and fetal development, as well as after birth, from a variety of metazoans in several tissues suggests coordination of gene expression between the mitochondria and the nucleus in the transition from fetal to neonatal life, and for the first time identifies its conservation in vertebrates. (Cover art by Lynn Fellman, www.FellmanStudio.com. The concept began with pencil sketches, which were redrawn with digital pen to create layers of overlapping translucent shapes. Icons modified from iStock.com/Betka82 [organs] and iStock.com/Dejanj01 [animals]. [For details, see Medini and Mishmar, pp. 459–474.])