Laser microirradiation of the nucleolar organizer in cells of the rat kangaroo (Potorous tridactylis)

Berns, Michael W.; Floyd, Alton D.; Adkisson, Karen P.; Cheng, Wanny K.; Moore, Landon L.; Hoover, G A; Ustick, K.; Burgott, Susan L.; Osial, T.

doi:10.1016/0014-4827(72)90449-1

Cited by 29 publications

(9 citation statements)

References 15 publications

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“…This observation may be relevant to differences in plus-end shrinkage rates observed in migrating newt cells when microtubules were either parallel to the leading edge of the cell ͑7.6 m / min͒ or perpendicular to the leading edge ͑5.2 m / min͒. 26 Our experimental results are consistent with these observations, and they may be explained by differences in the local structure and chemistry at the cell edge versus the nucleus. This is also consistent with recent studies that suggest stress fibers and the surrounding environment, specifically motor proteins and extracellular matrix components, can affect cytoskeletal dynamics.…”

Section: Discussionsupporting

confidence: 87%

“…It is clear that the variability is great between cell types, and even from different laboratories working with the same cell type, i.e., PtK1 cells with shrinkage rates of 7.4 m / min 26 and 19.8 m / min. 21 In this case, the experiments were done six years apart, and it is possible that the passage numbers for the PtK1 cells used were substantially different.…”

Section: Discussionmentioning

confidence: 99%

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Laser nanosurgery of single microtubules reveals location-dependent depolymerization rates

et al. 2007

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Section: Discussionsupporting

confidence: 87%

Section: Discussionmentioning

confidence: 99%

Laser nanosurgery of single microtubules reveals location-dependent depolymerization rates

et al. 2007

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“…Rat kangaroo cells (PTKz) were obtained from the American Type Culture Collection and were grown as monolayer cultures in a modified Eagle's medium (Berns et at., 1972).…”

Section: Methodsmentioning

confidence: 99%

“…Gerbi (1971) has investigated the possibility that sites of ribosomal (nucleolar) genes occur outside the secondary constriction in Sciara corprophila. In Potorous tissue culture cells, it has been d e m o n s t r a t e d that m i c r o i r r a d i a t i o n o f the nucleolar organizer site results either in the p r o d u c t i o n o f a c o m p e n s a t o r y nucleolus a p p a r e n t l y from some other c h r o m o s o m a l region, or the p r o d u c t i o n o f n u m e r o u s micronucleoli following cell division (Ohnuki et al, 1975;Berns et al, 1972).…”

Section: Introductionmentioning

confidence: 99%

Nucleoli and ploidy in Potorous cells (PTK2) in vitro

Branch

Berns

1976

Chromosoma

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Abstract. Most cells of the male PTK2 cell line contain one nucleolus, and they are diploid. However, a proportion of cells have more than one nucleolus. Cells with two and three nucleoli were isolated and cloned into viable populations. Greater than 90% of the cells in these clonal populations maintained the abnormal nucleolar number of the originally isolated cell. Karyotype analysis of cells with two and three nucleoli demonstrated that the cells were respectively tetraploid and hexaploid. It was concluded that in PTK2 cells, nucleolarity is a good index of ploidy even if the ploidy level is abnormal. Furthermore, long term monitoring of the tetraploid cells demonstrated virtually no tendency towards reversion to the diploid condition as suggested by other studies in Potorous.

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“…Encouraged by their initial successes, this team began a series of studies, based on UV and later visible spectrum laser beams, on how cells react to the selective removal of various structures from the nucleolar organizer/primary constriction (Berns and Cheng, 1971;Berns et al, 1970bBerns et al, , 1972Ohnuki et al, 1972) to the centrosome region (Berns and Richardson, 1977;Peterson and Berns, 1978). These studies were conducted on cells sensitized with chemical fluorophores such as acridine orange.…”

Section: B the Middle Years: Laser-based Microirradiationmentioning

confidence: 99%

Laser Microsurgery in the GFP Era: A Cell Biologist's Perspective

Magidson

Lončarek

Hergert

et al. 2007

Methods in Cell Biology

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Modern biology is based largely on a reductionistic "dissection" approach-most cell biologists try to determine how complex biological systems work by removing their individual parts and studying the effects of this removal on the system. A variety of enzymatic and mechanical methods have been developed to dissect large cell assemblies like tissues and organs. Further, individual proteins can be inactivated or removed within a cell by genetic manipulations (e.g., RNAi or gene knockouts). However, there is a growing demand for tools that allow intracellular manipulations at the level of individual organelles. Laser microsurgery is ideally suited for this purpose and the popularity of this approach is on the rise among cell biologists. In this chapter, we review some of the applications for laser microsurgery at the subcellular level and describe practical requirements for laser microsurgery instrumentation demanded in the field. We also outline a relatively inexpensive but versatile laser microsurgery workstation that is being used in our laboratory. Our major thesis is that the limitations of the technology are no longer at the level of the laser, microscope, or software, but instead only in defining creative questions and in visualizing the target to be destroyed.At last in an incredible manner he [Archimedes] burned up the whole Roman fleet. For by tilting a kind of mirror toward the sun he concentrated the sun's beam upon it; and owing to the thickness and smoothness of the mirror he ignited the air from this beam and kindled a great flame, the whole of which he directed upon the ships that lay at anchor in the path of the fire, until he consumed them all.1 I. History of the Field A. The Genesis of "Micro-Photo-Surgery"The origins of Cell Biology as a branch of "natural philosophy" can be traced to the English polymath Robert Hooke who, using a hand-crafted, leather and goldtooled compound light microscope (LM), published a book containing elaborate drawings of magnified objects which he called Micrographia. In this book, which became an immediate best-seller (and has been reprinted countless times), Hooke used the term "cell" to describe the repeating units seen in magnified slices of cork that resembled the monk cells of a monastery. Ironically, these repeating units were not actual cells but rather just the cellulose walls that surround cells in plant tissues. It took another 175 years of optical development and exploration, before Schleiden and Schwann (1839) convincingly asserted that cells are the fundamental building blocks of all life. In 1855, the Prussian physician and politician Virchow postulated that cells arise only from preexisting cells by reproduction and cannot be formed de novo from amorphous "living matter" or "protoplasma." This principle, which Virchow eloquently 1 Dio's Roman History, translated by Earnest Cary Loeb Classical Library, Harvard University Press, Cambridge, 1914, Vol. II, p. 171. NIH Public Access Author ManuscriptMethods Cell Biol. Author manuscript; availabl...

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Laser microirradiation of the nucleolar organizer in cells of the rat kangaroo (Potorous tridactylis)

Cited by 29 publications

References 15 publications

Laser nanosurgery of single microtubules reveals location-dependent depolymerization rates

Laser nanosurgery of single microtubules reveals location-dependent depolymerization rates

Nucleoli and ploidy in Potorous cells (PTK2) in vitro

Laser Microsurgery in the GFP Era: A Cell Biologist's Perspective

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