Publication Date

2000

Document Type

Dissertation/Thesis

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Biological Sciences

LCSH

Hydroida; Cloning

Abstract

Hydractinia symbiolongicarpus and Podocoryna carnea are colonial marine hydroids capable of reproducing both sexually and asexually. Asexual reproduction, by colony fragmentation, produces a genetic clone of the parent colony. This study examines the effect of extreme cloning rates on colony growth rate, oxygen uptake rate, and colony morphology. Colonies of both species maintained for an extended period of time in a state of constant vegetative growth by repeated cloning (“growing” colonies) grew more slowly than genetically equal replicates which were restricted from vegetative growth and underwent no cloning (“restricted” colonies). For one species, the growing colonies used oxygen at a higher rate; for the other species, no difference was detected, although the sample size was small. A difference in colony morphology was found, with the restricted colonies exhibiting a more “sheet-like” shape, while their growing counterparts appeared more “runnerlike.” Subsequent to these experiments, in the third winter of treatment, all colonies experienced a severe tissue regression. Within 6 months after this event, the colonies had regrown to their former sizes. A growth assay at this point revealed no difference in growth rate, suggesting an epigenetic basis for these results.

Comments

Includes bibliographical references (pages [26-28])

Extent

v, 25, [3] pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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