Transformation of chromosomal accompanying differentiation of plant cells

The size of the genome of angiosperms, although determined only for 1.4% of described species, is very diverse. Comparative genomic studies have shown that differences in genome size result mainly from differences in the amount of repeated sequences, whereas the number of genes is similar. The role of non-coding repetitive sequences is controversial. These hypotheses indicating their parasitic nature, as well as data about their adaptive significance. Unexplained are the mechanisms leading to increasing the size of the genome, and even more so for its reduction.

The dominant component of the genome of angiosperms are repetitive sequences, including retroelements. Various content of these sequences results in variation in size of the genome within both species and genus. Any type of repetitive sequences may be species-specific or-genomowo commonly occur either within the genus or families exhibiting the characteristic chromosomal location. The characteristics of species include speckled pattern and chromosomal location of 18S-5, 8S-25S rDNA and 5S rDNA.

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