ISSN:
1432-2242
Keywords:
Nicotiana
;
Chloroplast DNA
;
Restriction fragments
;
Deletion
;
Evolution
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Nicotiana chloroplast genomes exhibit a high degree of diversity and a general similarity as revealed by restriction enzyme analysis. This property can be measured accurately by restriction enzymes which generate over 20 fragments. However, the restriction enzymes which generate a small number (about 10) of fragments are extremely useful not only in constructing the restriction maps but also in establishing the sequence of ct-DNA evolution. By using a single enzyme, Sma I, a elimination and sequential gain of its recognition sites during the course of ct-DNA evolution is clearly demonstrated. Thus, a sequence of ct-DNA evolution for many Nicotiana species is formulated. The observed changes are all clustered in one region to form a “hot spot” in the circular molecule of ct-DNA. The mechanisms involved for such alterations are mostly point mutations but inversion and deficiency are also indicated. Since there is a close correlation between the ct-DNA evolution and speciation in Nicotiana a high degree of cooperation and coordination betwen organellar and nuclear genomes is evident.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00261515
Permalink
