Growth and Vegetative Development
Cordle, Angela R. , Irish, Erin , Chi-Lien, Cheng .
The Use of Apogamy to Investigate the Alternation of Generations in Ceratopteris richardii.
Two distinct generations, the sporophyte and the gametophyte, alternate to complete the life cycle of all land plants. The sporophyte generation is capable of undergoing meiosis, which halves the chromosome number and forms the first cell in the gametophyte generation, the spore. The gametophyte generation produces gametes, which undergo fertilization to produce the zygote, the first cell of the sporophyte. Both generations start from a single cell, but are directed by a single genome to develop into body types that are typically very different in size, morphology, and habit. The regulatory mechanisms that lead to the development of the vastly different generations are unknown. We have begun to use apogamy in ferns as a tool to investigate the alternation of generations in plants. Apogamy is a phenomenon in which fertilization is circumvented, thereby producing a sporophyte directly from the vegetative cells of a gametophyte without chromosome doubling. We have successfully induced apogamy in the model fern Ceratopteris richardii by culturing gametophytes in the presence of high levels of exogenous sugars. We also have identified the minimum culture time required by developing C. richardii gametophytes to gain competence for the apogamous production of gametophytes. Using this system, we are in the process of identifying differentially expressed genes at the stage in which apogamy competence is induced.
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1 - University of Iowa, Department of Biology, 143 Biology Building, Iowa City, Iowa, 52242, USA
2 - University of Iowa, Department of Biology
alternation of generations
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM