Faculty Opinions recommendation of The transforming parasite Theileria co-opts host cell mitotic and central spindles to persist in continuously dividing cells.

In fed hydra or excised regenerating peduncles there are increases in the mitotic indices of both digestive cells and the symbiotic algae that reside within them. Conversely, algal and digestive cell mitotic indices decrease in starved hydra. The temporal relationships of algal and host cell division differ in fed hydra and regenerating peduncles. After feeding, algal and digestive cell mitotic indices both reach a peak at about the same time; during regeneration, first the algae and then the digestive cells divide. Thus, mitotic digestive cells in regenerating peduncles contain more algae than those in gastric regions of fed hydra. However, in both cases mitotic digestive cells contain more algae than non-mitotic cells. The algae appear to be partitioned at random between daughter digestive cells at teleophase. It is suggested that the division of the symbiotic algae is closely related to that of the digestive cells in which they maintained. Mitosis of algae is stimulated by host cell mitosis, but in non-dividing cells algal mitosis is restricted. Possible mechanisms by which the host digestive cells could restrict algal division are discussed.

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The Transforming Parasite Theileria Co-opts Host Cell Mitotic and Central Spindles to Persist in Continuously Dividing Cells

PLoS Biology ◽

10.1371/journal.pbio.1000499 ◽

2010 ◽

Vol 8 (9) ◽

pp. e1000499 ◽

Cited By ~ 47

Author(s):

Conrad von Schubert ◽

Gongda Xue ◽

Jacqueline Schmuckli-Maurer ◽

Kerry L. Woods ◽

Erich A. Nigg ◽

...

Keyword(s):

Host Cell ◽

Dividing Cells

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Targeting mitotic chromosomes: a conserved mechanism to ensure viral genome persistence

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2008.1642 ◽

2009 ◽

Vol 276 (1662) ◽

pp. 1535-1544 ◽

Cited By ~ 21

Author(s):

Katherine M Feeney ◽

Joanna L Parish

Keyword(s):

Host Cell ◽

Genetic Material ◽

Membrane Integrity ◽

Mitotic Chromosomes ◽

Nuclear Retention ◽

Viral Genomes ◽

Daughter Cells ◽

Dna Damage Checkpoints ◽

Low Copy Number ◽

Dividing Cells

Viruses that maintain their genomes as extrachromosomal circular DNA molecules and establish infection in actively dividing cells must ensure retention of their genomes within the nuclear envelope in order to prevent genome loss. The loss of nuclear membrane integrity during mitosis dictates that paired host cell chromosomes are captured and organized by the mitotic spindle apparatus before segregation to daughter cells. This prevents inaccurate chromosomal segregation and loss of genetic material. A similar mechanism may also exist for the nuclear retention of extrachromosomal viral genomes or episomes during mitosis, particularly for genomes maintained at a low copy number in latent infections. It has been heavily debated whether such a mechanism exists and to what extent this mechanism is conserved among diverse viruses. Research over the last two decades has provided a wealth of information regarding the mechanisms by which specific tumour viruses evade mitotic and DNA damage checkpoints. Here, we discuss the similarities and differences in how specific viruses tether episomal genomes to host cell chromosomes during mitosis to ensure long-term persistence.

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Bacteriophages Associated with Turkey Coecums in Bluecomb-Infected and Healthy Birds

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100063044 ◽

1969 ◽

Vol 27 ◽

pp. 226-227

Author(s):

A. E. Ritchie

Keyword(s):

Host Cell ◽

Causal Relationship ◽

Cell Cultures ◽

Cell Interaction ◽

Etiologic Agent ◽

Viral Origin ◽

Intestinal Contents ◽

Host Cell Interaction

The cause of bluecomb disease in turkeys is unknown. Filtration of infective intestinal contents suggests a viral origin. To date, it has not been possible to isolate the etiologic agent in various cell cultures. The purpose of this work was to characterize as many virus-like entities as were recognizable in intestines of both healthy and bluecomb-infected turkeys. By a comparison of the viral populations it was hoped that some insight might be gained into the cause of this disease. Studies of turkey hemorraghic enteritis by Gross and Moore (Avian Dis. 11: 296-307, 1967) have suggested that a bacteriophage-host cell interaction may bear some causal relationship to that disease.

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The Infection of Cells by Bullet-Shaped Viruses

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100063779 ◽

1969 ◽

Vol 27 ◽

pp. 372-373

Author(s):

Frederick A. Murphy ◽

Alyne K. Harrison ◽

Sylvia G. Whitfield

Keyword(s):

Electron Microscopy ◽

Physical Properties ◽

Host Cell ◽

Thin Section ◽

Cultured Cells ◽

Cell Infection ◽

Thin Section Electron Microscopy ◽

Section Electron ◽

Section Electron Microscopy

The bullet-shaped viruses are currently classified together on the basis of similarities in virion morphology and physical properties. Biologically and ecologically the member viruses are extremely diverse. In searching for further bases for making comparisons of these agents, the nature of host cell infection, both in vivo and in cultured cells, has been explored by thin-section electron microscopy.

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