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Published on: December 16, 2015
Affinity Distance Values among Somatic Metaphase Chromosomes in Maize.
1Department of Plant Sciences, University of Western Ontario, London, Ontario N6A 3K7.
Genetics
|January 1, 1978
Summary
Chemical agents used to arrest cell division in maize (Zea mays) chromosomes reveal mechanisms of homologous chromosome association, suggesting microtubules and nucleolus involvement. This study provides insights into chromosome behavior and somatic association.
Area of Science:
- Cytogenetics
- Plant biology
- Molecular biology
Background:
- Understanding chromosome behavior and spatial organization within the nucleus is crucial for comprehending genetic stability and inheritance.
- Somatic association of chromosomes has been reported in various species, but the underlying mechanisms and extent remain debated.
Purpose of the Study:
- To investigate the spatial relationships between homologous and non-homologous chromosomes in maize root-tip cells.
- To determine the influence of different metaphase arrest agents on chromosome separation and association patterns.
- To explore potential mechanisms maintaining primary homologous chromosome association.
Main Methods:
- Measurement of inter-chromosomal distances in maize root-tip metaphase chromosomes from multiple stocks.
- Application of various chemical agents (cold, 8-hydroxyquinoline, colchicine, monobromonaphthalene) for metaphase arrest.
- Calculation of standardized affinity-distance values for homologous and non-homologous chromosome pairs.
- Statistical comparison of observed distances with theoretical random distribution values.
Main Results:
- Cold arrest showed specific separation patterns for homologous pairs (X least, I most separated).
- Chemical agents generally increased homologous chromosome separation, except for pair I, driving populations towards random distribution.
- Limited primary non-homologous chromosome association was evidenced by significant deviations from random distribution in cold-arrested cells.
Conclusions:
- Primary homologous chromosome association is likely maintained by mechanisms involving microtubules and the nucleolus.
- Chemical metaphase arrest influences chromosome spatial arrangements, with homologous pairs approaching random distribution.
- The findings contribute to understanding somatic chromosome association and offer avenues for cytogenetic manipulation in maize.
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