ISSN:
1615-6110
Keywords:
Angiosperms
;
Poaceae
;
millets
;
Homogeneous/heterogeneous repeat families
;
fossil repeats
;
genome turnover
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Based on optical reassociation studies of total nuclear DNAs at 55°C, 62°C, 69°C, and 75°C, it is concluded that repeat families in great millet, little millet, barn yard millet and finger millet are heterogeneous while those of fox tail millet are homogeneous. In great millet, almost one third of the sequences that behave as single copy at standard conditions are actually fossil repeats. Such “fossil” repeats are not a prominent feature of the genomes of the other four millets. The ratios of sequence complexities of repeats isolated at 75°C to those isolated at 55°C are 2.2, 3.5, 81, and 0.3 in case of little millet, finger millet, fox tail millet, and great millet respectively. On the basis of the above three observations, it is suggested that among these millets, the rate of turnover of the genome of fox tail millet is the slowest while that of great millet is the fastest. Such comparative estimates of differences in the turnover rates of genomes of related species are expected to generate useful data about the evolution of genomes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00937593
