The bud neck is a constriction between the mother and the daughter cell (bud) in an organism that reproduces by budding. This structure comprises the septin ring, an hourglass-shaped collar around the mother-bud neck, which splits into two rings flanking the division plane at cytokinesis and that acts as a diffusion barrier to maintain polarity factors in the bud and as a scaffold to recruit actomyosin contractile ring components.
