ISSN:
1573-5028
Keywords:
Arabidopsis thaliana
;
gene silencing
;
MMS treatment
;
Nicotiana tabacum
;
Poisson distribution
;
UV irradiation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Intrachromosomal homologous recombination in whole tobacco plants was analyzed using β-glucuronidase as non-selectable marker. We found that recombination frequencies were additive for transgenes in allelic positions and could be enhanced by treatment of plants with DNA-damaging agents. We compared the patterns of distribution of recombination events of different transgenic lines of tobacco and Arabidopsis with the respective Poisson distributions. Some lines showed Poisson-like distributions, indicating that recombination at the transgene locus was occurring in a random fashion in the plant population. In other cases, however, the distributions deviated significantly from Poisson distributions indicating that for specific transgene loci and/or configurations recombination events are not randomly distributed in the population. This was due to overrepresentation of plants with especially many as well as especially few recombination events. Analysis of one tobacco line indicated furthermore that the distribution of recombination events could be influenced by treating the seedlings with external factors. Our results suggest that different plant individuals, or parts of them, might exhibit different transient ‘states’ of recombination competence. A possible model relating ‘recombination silencing’ and transcription silencing to heterochromatization of the transgene locus is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00020247
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