Bub1-related kinase (BubR1) encodes a motif-rich protein with a C-terminal serine-threonine kinase domain. During prometaphase and metaphase, it plays important roles in spindle assembly checkpoint signalling, stabilization of kinetochore-microtuble attachments and chromosome alignment. It is also essential to maintain sister-chromatid cohesion during meiotic progression and for normal maintenance of Synaptonemal Complex in females.

Borealin-related (borr) encodes one of the three targeting subunits for the product of aurB in the chromosomal passenger complex. It helps to target the complex to the centromere region of chromosomes and the cleavage furrow during cytokinesis. At centromeres the complex is involved both in pausing mitotic progression when there are chromosome mis-attachments and in correcting those mis-attachments. At the cleavage furrow, the complex is involved in regulating the process of abscission (cell separation).

Aurora B (aurB) encodes a serine-threonine kinase and member of the chromosomal passenger complex. It plays multiple roles in mitosis including the correction of erroneous chromosome-spindle interactions, chromosome condensation, kinetochore assembly, spindle assembly checkpoint and cytokinesis.

Protein ORD; Essential for proper maintenance of sister-chromatid cohesion in both male and female meiosis. Mutations in ord cause premature separation of the sister chromatids in meiosis I and random segregation in both meiotic divisions. Required for chiasma maintenance in female meiosis. Mutations in ord reduce recombination in female meiosis.

Inner centromere protein (Incenp) encodes a component of the chromosomal passenger complex, acting as a subunit that targets and activates the product of aurB. It controls different processes during cell division, including regulation of chromosome structure, kinetochore-microtubule error correction, chromosome segregation and cytokinesis.

Widerborst (wdb) encodes a B' regulatory subunit of the serine/threonine phosphatase complex PP2A. It regulates Hedgehog, protein kinase B and insulin receptor signaling pathways.

Bub1 kinase (Bub1) encodes a spindle checkpoint protein regulating chromosome congression. It also contributes to clathrin-dependent endocytosis of pathogens.

Wings apart-like (wapl) encodes a protein that interacts with the product of pds5 to form the releasin complex that enables sister chromatid separation at mitosis by removing the cohesin ring complex from chromosomes. It also influences gene activation and silencing through interactions with cohesin.

Serine/threonine-protein phosphatase PP2A; Microtubule star (mts) encodes the catalytic subunit of protein phosphatase 2A. It is involved in various developmental processes and signaling pathways, such as Hh signaling and Wingless signaling; Belongs to the PPP phosphatase family. PP-2A subfamily.