Scan Science and Technology
Contact Leading Edge Experts & Companies
The Experts below are selected from a list of 690 Experts worldwide ranked by ideXlab platform
Conly L Rieder – One of the best experts on this subject based on the ideXlab platform.
stuck in division or passing through what happens when cells cannot satisfy the spindle assembly checkpointDevelopmental Cell, 2004Co-Authors: Conly L Rieder, Helder MaiatoAbstract:
Abstract Cells that cannot satisfy the spindle assembly checkpoint (SAC) are delayed in mitosis (D-mitosis), a fact that has useful clinical ramifications. However, this delay is seldom permanent, and in the presence of an active SAC most cells ultimately escape mitosis and enter the next G1 as tetraploid cells. This review defines and discusses the various factors that determine how long a cell remains in mitosis when it cannot satisfy the SAC and also discusses the cell’s subsequent fate.
Wei Wang – One of the best experts on this subject based on the ideXlab platform.
subcellular localization and role of ran1 in tetrahymena thermophila amitotic macronucleusFEBS Journal, 2012Co-Authors: Haixia Liang, Jing Xu, Dan Zhao, Huaru Tian, Xuxia Yang, Aihua Liang, Wei WangAbstract:
Amitosis, a direct method of cell division is common in ciliated protozoan, fungi and some animal and plant cells. During Amitosis, intranuclear microtubules are reorganized into specified arrays which assist in separation of nucleus, despite lack of a bipolar spindle. However, the regulation of Amitosis is not understood. Here, we focused on the localization and role of mitotic spindle assembly regulator: Ran GTPase (Ran1) in macronuclear Amitosis in binucleated protozoan Tetrahymena thermophila. HA-tagged Ran1 was localized in the macronucleus throughout the cell cycle of Tetrahymena during vegetative growth, and the accessory factor binding domains of Ran1 contributed to its macronuclear localization. Incomplete somatic knockout of RAN1 resulted in aberrant intramacronuclear microtubule array formation, missegregation of macronuclear chromosomes and ultimately blocked macronuclei proliferation. When the Ran1 cycle was perturbed by overexpression of Ran1T25N (GDP-bound Ran1-mimetic) or Ran1Q70L (GTP-bound Ran1-mimetic), intramacronuclear microtubule assembly was inhibited or multi-micronucleate cells formed. These results suggest that Ran GTPase pathway is involved in assembly of a specialized intramacronuclear microtubule network and coordinates amitotic progression in Tetrahymena.
Andre R. O. Cavalcanti – One of the best experts on this subject based on the ideXlab platform.
Amitotic chromosome loss predicts distinct patterns of senescence and non-senescence in ciliates.Protist, 2015Co-Authors: David W. Morgens, Andre R. O. CavalcantiAbstract:
Over time and repeated asexual divisions, many ciliate species display the characteristics of senescence, reduced fecundity and increased mortality. Their only path to recovery is sexual conjugation or autogamy. While more traditional models of cellular aging have been proposed, one of the most accepted explanations relies on the faulty mechanism by which ciliates duplicate their somatic nucleus, a process referred to as Amitosis. Amitosis involves the random segregation of chromosomes with no consideration for homology. Over subsequent divisions, chromosome copy numbers will fluctuate until an entire chromosome is lost, resulting in death. Via simulations of this process, we find that senescence and death via chromosome loss is not the only possible result of Amitosis. Random chromosome loss is less damaging to populations than previously thought, and strict adherence to the model predicts that Paramecium tetraurelia would not senesce. A combination of the reciprocal nature of Amitosis and lethal selection against low-copy number chromosomes is responsible for this startling prediction. Additionally, our results provide an alternate explanation to recent evidence for selection on chromosome copy number in Tetrahymena thermophila and peculiar patterns of senescence in Tetrahymena pyriformis.