Shoot growth depends upon meristems,pools of stem cells that are maintained in a number of ways,including a negative feedback loop between the CLA VATA pathway and the WUSCHEL homeobox gene.CLAVATA signaling involves a secreted peptide,CLAVATA3 (CLV3),and its perception by cell surface leucine-rich repeat (LRR) receptors,including the CLV1 receptor kinase,and an LRR receptor-like protein,CLV2.We are interested in finding novel players in the CLV-WUS pathway,as well as new regulators that could affect meristem size in parallel pathways.Maize provides a rich source of new information,because there are many clavata-type mutants,and their isolation is becoming routine.