Project description:Kinetochores are essential macromolecular complexes anchoring chromosomes to the mitotic spindle, ensuring faithful cell division. Despite their critical role, the structural organization of kinetochores over large centromeric regions and across diverse species remains poorly understood. We present the inner kinetochore (CCAN) structure of the silkmoth Bombyx mori, an insect without the canonical centromeric CENP-A gene and with chromosome-wide centromeric activity (holocentric). Our analyses reveal a ring-shaped complex with structural parallels to the known human and yeast kinetochores. Notably, B. mori CCAN incorporates four previously uncharacterized proteins, Centromeric Subunits 1-4, which have unexpected evolutionary relationships to the outer kinetochore Dam1/DASH complex. We demonstrate that CCAN binds DNA as a distinctive head-to-head dimer, folding the DNA into a loop and generating an alternative point-centromere-like architecture poised for chromosome segregation. Our work establishes this self-contained CCAN dimer as a key structural unit that forms the basis of a holocentric organization and suggests that large-scale centromere architectures can emerge from the modular arrangement of such discrete kinetochore units.
Project description:Little is known about plant pathogenic response to parasitic plants, although some parasitic plants affect crop production in certain areas. To study this, we chose Glycine max as the model host plant and investigated changes in expression patterns after parasitization by Cuscuta using microarrays. Transcriptional change of Glycine max stem with and without Cuscuta at 2 different stages were compared