Deletion of an internal PsiI fragment, amino acids 19 to 110.
anaphase & condensed nuclear chromosome
Expression of homozygous CycB3Δ at the permissive temperature prevents or severely delays cell cycle progression at late anaphase.
When CycB3Δ is induced during the G2 phase of cycle 14, cytokinesis does progress albeit slowly to completion and initiation is delayed.
Heatshock expression of CycB3Δ produces embryos with arrested cells with condensed chromosomes at the poles. Cells proceed through the metaphase/anaphase transition with normal timing and separate their chromosomes with kinetics similar to wild-type, but then arrest with condensed chromosomes at the poles. This remains stable for at least 20 minutes in most cases. The separation of the spindle poles during anaphase B occurs as normal, however the organisation of the midbody is abnormal. Cells either lack the compacted foci of tubulin of the normal midbody, or showed foci lacking normal symmetry and organisation. Sometimes a more dynamic arrest is seen in which individual chromosomes leave the spindle pole and travel back along the spindle at rates comparable to anaphase rates. Occasionally, these chromosomes reach the opposite pole. Often, in cells where this phenomenon occurs, the spindle rotates in the plane of the epithelium. Cytogenetic furrow formation appears to proceed normally.
Expression causes a mitotic block in late anaphase (after sister chromosome separation).
CycB3Δ has abnormal cytokinesis phenotype, enhanceable by pbl2
CycB3Δ is an enhancer of abnormal cytokinesis phenotype of pbl2
CycBΔ90, CycB3Δ, Cdk1hs.PS is a non-suppressor of abnormal mitotic cell cycle | embryonic stage phenotype of CycAC8LR1
CycBΔ90, CycB3Δ, stghs.PE2 is a non-suppressor of abnormal mitotic cell cycle | embryonic stage phenotype of CycAC8LR1
Cdk1AF.hs, CycAC8LR1, CycB3Δ, CycBΔ90 has abnormal mitotic cell cycle | embryonic stage phenotype
CycBΔ90, CycB3Δ, Cdk1hs.PS is a non-suppressor of embryonic epidermis phenotype of CycAC8LR1
CycBΔ90, CycB3Δ, stghs.PE2 is a non-suppressor of embryonic epidermis phenotype of CycAC8LR1
Cdk1AF.hs, CycAC8LR1, CycB3Δ, CycBΔ90 has embryonic epidermis phenotype
Coexpression of three transgenes, cdc2AF.hs, CycBΔ90, and CycB3Δ, restores the entry of epidermal cells in CycAC8LR1 embryos into mitosis 16. After entry into mitosis, the epidermal cells are unable to complete this division.
Coexpression of the transgenes, cdc2hs.PS, CycBΔ90, and CycB3Δ, does not restore the entry of epidermal cells in CycAC8LR1 embryos into mitosis 16. Likewise, coexpression of stghs.PE2, CycBΔ90 and CycB3Δ does not suppress the phenotype.