Molecular organization of great millet (Sorghum vulgare) DNA.

Approximately 52% of the nuclear genome of great millet (Sorghum vulgare) consists of repetitive DNA which can be grouped into very fast, fast and slow components. The reiteration frequencies of the fast and slow reassociating components are 7000 and 92 respectively. Approximately 90% of the genome consists of repeated sequences interspersed amongst themselves and with single copy sequences. The interspersed repeat sequences are of three sizes viz. > 1·5 kilobase pairs, 0·5–1·0 kilobase pairs and 0·15–0·30 kilobase pairs while the size of the single copy sequences is 3·0 kilobase pairs. Hence the genome organization of great millet is essentially of a mixed type.

Analysis of bovidae genomes: Arrangement of repeated and single copy DNA sequences in bovine, goat and sheep.

Approximately 43-60% of the total genome in bovine, goat and sheep consisted of interspersed repeated and single copy DNA sequences. Most of the interspersed repeated DNA sequences were 1500-2400 nucleotide pair long while a minor portion was more than 4000 nucleotide pair long in goat and sheep and 3200 nucleotide pair long in bovine. About 1/3rd of single copy sequence were interspersed and their length was in the range of 1000-1500 nucleotide pairs.

DNA Sequence organization In finger millet (Eleusine coracana).

Approximately 39 to 49% of the genome of finger millet consists of repetitive DNA sequences which intersperse with 18% of single copy DNA sequences of 1900 nucleotide pairs. Agarose gel filtration and electrophoresis experiments have yielded the sizes of interspersed repeated sequences as 4000-4200 nucleotide pairs and 150-200 nucleotide pairs. Approximately 20% of the repeated DNA sequences (4000-4200 nucleotide pairs) are involved in long range interspersion pattern, while 60% of the repeated DNA sequences (150-200 nucleotide pairs) are involved in short period interspersion pattern. Based on the data available in literature and the results described here on DNA sequence organization in plants, it is proposed that plants with haploid DNA content of more than 2.5 pg exhibit mostly the short period interspersion pattern, while those with haploid DNA content of less than 2.5 pg show diverse patterns of genome organization.