Article of Significant Interest Selected from This Issue by the Editors

Where Chemistry Regulates Morphogenesis: Chitin—β(1-3)Glucan Cross-Linkages Control Growth at the Yeast Mother-Bud Neck

After initial budding, the Saccharomyces cerevisiae mother-bud neck, where cytokinesis eventually occurs, maintains a constant shape and size throughout the cell cycle, under the redundant control of the chitin and septin rings. Previous work showed that loss of that control leads to neck widening and lack of cytokinesis. Cabib et al. (p. 388–400) found that β(1-3)glucan, the major structural component of the cell wall, can be separated into two fractions, one of very high molecular weight and the other smaller and polydisperse. The latter was identified as the portion that is being remodeled in buds during growth. The β(1-3)glucan attached to chitin, specifically localized at the mother-bud neck, belongs to the high-molecular-weight kind, suggesting that the linkage between the two polysaccharides maintains the cell wall at the neck in a quiescent state.