Does microR159 regulation of most conserved targets in Arabidopsis have negligible phenotypic effects?
This study presents a novel explanation for a paradox common to plant and animal miRNA systems, where among many potential miRNA-target relationships usually only a few appear physiologically relevant. The identification of a quiescent miR159c:target gene regulatory module in anthers provides a likely rationale for the presence of conserved miR159 binding sites in many targets for which miR159 regulation has no obvious functional role. Remnants from the demise of such modules may lead to an overestimation of miRNA regulatory complexity when investigated using bioinformatic, 5'-RACE or transgenic approaches.
The authors' results support the concept of an interhemispheric "rivalry." They demonstrate the utility of repetitive transcranial magnetic stimulation to explore the functional facilitation of the unstimulated counterpart motor cortex, presumably via suppression of activity in the stimulated motor cortex and transcallosal inhibition.