Measurements of forces produced by the mitotic spindle using optical tweezers

Ferraro-Gideon, Jessica; Sheykhani, Rozhan; Zhu, Qingyuan; Duquette, Michelle L.; Berns, Michael W.; Forer, Arthur

doi:10.1091/mbc.e12-12-0901

Cited by 34 publications

(49 citation statements)

References 73 publications

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“…1) [21,23,27]. Briefly, the optical scissors were generated by a pulsed femtosecond 740nm beam (Ti:Sapphire), and the optical trap was a continuous, 1064nm (Nd:YVO4) beam.…”

Section: Methodsmentioning

confidence: 99%

“…Early optical trapping experiments demonstrated chromosomes could be manipulated by an optical trap in vitro [18] and in vivo [19,20], estimating a force to move chromosomes of~30 pN. Later trapping experiments on Chinese hamster ovary cells found 0.1-12 pN sufficient to move extracted chromosomes [21], and 2-10 pN stopped in vivo chromosome movement in Mesostoma and crane-fly cells [23]. However, in pioneering micromanipulation experiments with Melanoplus spermatocytes R.B Nicklas impaled moving anaphase chromosomes with a glass needle and determined that a force of 700 pN was needed to stop chromosome movement [15].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Mitotic tethers connect sister chromosomes and transmit “cross-polar” force during anaphase A of mitosis in PtK2 cells

Ono

Preece

Duquette

et al. 2017

Biomed. Opt. Express

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Originally described in crane-fly spermatocytes, tethers physically link and transmit force between the ends of separating chromosomes. Optical tweezers and laser scissors were used to sever the tether between chromosomes, create chromosome fragments attached to the tether which move toward the opposite pole, and to trap the tethered fragments. Laser microsurgery in the intracellular space between separating telomeres reduced chromosome strain in half of tested chromosome pairs. When the telomere-containing region was severed from the rest of the chromosome body, the resultant fragment either traveled towards the proper pole (poleward), towards the sister pole (cross-polar), or movement ceased. Fragment travel towards the sister pole varied in distance and always ceased following a cut between telomeres, indicating the tether is responsible for transferring a cross-polar force to the fragment. Optical trapping of cross-polar traveling fragments places an upper boundary on the tethering force of~1.5 pN.

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“…1) [21,23,27]. Briefly, the optical scissors were generated by a pulsed femtosecond 740nm beam (Ti:Sapphire), and the optical trap was a continuous, 1064nm (Nd:YVO4) beam.…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Mitotic tethers connect sister chromosomes and transmit “cross-polar” force during anaphase A of mitosis in PtK2 cells

Ono

Preece

Duquette

et al. 2017

Biomed. Opt. Express

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“…Measurements of the force required to pull chromosomes free from an optical trap were performed in order to estimate the forces exerted on chromosomes by a cell during cell division (mitosis) from the power required to halt the motion (Ferraro-Gideon et al, 2014). Since the exact size and refractive index of the chromosomes were uncertain, a further series of experiments and simulations on the escape of spheres from optical traps due an applied force were performed (Bui et al, 2015), revealing the dependence of the escape trajectory, and the escape force, on the trapping power and rate of increase of the applied force.…”

Section: Applications Of Simulationsmentioning

confidence: 99%

Theory and Practice of Computational Modeling and Simulation of Optical Tweezers

Nieminen

Preez-Wilkinson

Bui

et al. 2015

Optics in the Life Sciences

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Theory and practice of simulation of optical tweezers, Journal of Quantitative Spectroscopy and Radiative Transfer, http://dx.doi.org/10.1016/j.jqsrt.2016.12.026 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. AbstractComputational modelling has made many useful contributions to the field of optical tweezers. One aspect in which it can be applied is the simulation of the dynamics of particles in optical tweezers. This can be useful for systems with many degrees of freedom, and for the simulation of experiments. While modelling of the optical force is a prerequisite for simulation of the motion of particles in optical traps, non-optical forces must also be included; the most important are usually Brownian motion and viscous drag. We discuss some applications and examples of such simulations. We review the theory and practical principles of simulation of optical tweezers, including the choice of method of calculation of optical force, numerical solution of the equations of motion of the particle, and finish with a discussion of a range of open problems.

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“…Chromosome manipulation was performed in the collaborating lab [Ferraro-Gideon et al, 2013]. I performed the force calibration with the collaborating lab, published in Khatibzadeh et al [2014c].…”

Section: De Dtmentioning

confidence: 99%

“…A collaborating group, Michael Berns' group (University of California, Irvine and San Diego, USA), were measuring the motility forces of chromosomes during cell division. Their original experiment [Liang et al, 1994], and later refined experiment [Ferraro-Gideon et al, 2013], used optical tweezers to trap chromosomes of Potorous tridactylus (rat kangaroo) kidney (PtK2) cells during anaphase. As the chromosomes pulled apart, the optical trap held the chromosome stationary until it would escape from the trap.…”

Section: Chromosome Calibrationmentioning

confidence: 99%

Calibration of optical tweezers for force microscopy

Bui¹

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Optical tweezers are an important tool in biophysics for their ability to noninvasively control microscopic particles, and measure forces in cellular environments. The trap must be calibrated for there to be a quantified force measurement. In this thesis, I use simulation to investigate the forces in optical tweezers and calibration of these forces.There are many methods which can be used to calibrate the forces. I first discuss the use of escape force calibration in detail. Using a combination of dynamic simulation and force calculations, I find that there is a zero axial force contour in the optical trap, which affects escape force measurements and explains behaviour which has been previously observed. I then use this escape force calibration for the calibration of the motility forces of isolated chromosomes, which provides information for the calculation of chromosome mitotic forces.I then introduce a new method of calibration which does not require any knowledge of the particle being optically trapped, or its environment. This is a method of absolute calibration. I require only the assumption that the force-position curve is monotonic, making no assumptions about the sphericity of the trapped particle or viscosity of the medium. Using dynamic simulation of an optically trapped particle, I find that the accuracy and tolerance of this new method of absolute calibration is comparable or an improvement on that of other calibration methods.I then use my absolute calibration method for the calibration of nonoptical forces. I first discuss the calibration of forces from surfaces, then forces from swimmers. Through dynamic simulations, I find that wall forces can be calibrated with the combination of my absolute calibration method and another position-only calibration method. I find that for an analogue of biological swimmers, swimming with uniform velocity, the calibration is straightforward and resembles that of the walls. For a more complex swimming model, the calibration is not as straightforward and other factors may need to be included. Publications included in this thesisNo publications included. Contributions by others to the thesis

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Measurements of forces produced by the mitotic spindle using optical tweezers

Abstract: An optical trap is used to stop chromosome movement in spermatocytes from an insect and a flatworm and to stop pole movement in PtK cells. The forces required are much smaller than previously believed.

Cited by 34 publications

References 73 publications

Mitotic tethers connect sister chromosomes and transmit “cross-polar” force during anaphase A of mitosis in PtK2 cells

Mitotic tethers connect sister chromosomes and transmit “cross-polar” force during anaphase A of mitosis in PtK2 cells

Theory and Practice of Computational Modeling and Simulation of Optical Tweezers

Calibration of optical tweezers for force microscopy

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