[Answer] DNA methylation is a mechanism used by eukaryotes to do what?

Answer: inactivate genes DNA methylation involving the attachment of methyl groups to certain bases is a mechanism for the long-term inactivation of genes during development.
DNA methylation is a mechanism used by eukaryotes to do what?

DNA methylation is a biological process by which methyl groups are added to the DNA molecule. Methylation can change the activity of a DNA segment without changing the sequence. When located in a gene promoter DNA methylation typically acts to repress gene transcription.

In mammals DNA methylation is essential for normal development and is associated with a number of key processes including genomic imprinting X-chromosome inactivation repression of transposable elements aging and carcinogenesis.

In mammals DNA methylation is essential for normal development and is associated with a number of key processes including genomic imprinting X-chromosome inactivation repression of transposable elements aging and carcinogenesis. Two of DNA’s four bases cytosine and adenine can be methylated. Cytosine methylation is widespread in both eukaryotes and prokaryotes even though the rate of cytosine DNA methylation can differ greatly between species: 14% of cytosines are methylated in Arabidopsis thaliana 4% to 8% in Physarum 7.6% in Mus musculus 2.3% in Escherichia coli 0.03% in Drosophila 0.006% in Dictyostelium and virtually none (0.0002 to 0.0003%) in Caenorhabditis or fungi such as Saccharomyces cerevisiae and S. pombe (but not N. crassa ). Adenine methylation has been observed in bacterial plant and recently in mammalian DNA but has received considerably less attention. Methylation of cytosine to form 5-methylcytosine occurs at the same 5 position on the pyrimidine ring where the DNA base thymine s methyl group is located; the same position distinguishes thymine from the analogous RNA base uracil which has no methyl group. Spontaneous deamination of 5-methylcytosine converts it to thymine. This results in a T:G mismatch. Repair mechanisms then correct it back to the original C:G pair; alternatively they may substitute A for G turning the original C:G pair into a T:A pair effectively changing a base and introducing a mutation. This misincorporated base will not be corrected during DNA replication as thymine is a DNA base. If the mismatch is not repaired and the cell enters the cell cycle the strand carrying the T will be complemented by an A in one of the daughter cells such tha… Read more on Wikipedia

RNA-directed DNA methylation (RdDM) is a biological process in which non-coding RNA molecules direct the addition of DNA methylation to specific DNA sequences. The RdDM pathway is unique to plants although other mechanisms of RNA-directed chromatin modification have also been described in fungi and animals.To date the RdDM pathway is best characterized within angiosperms (flowering …

Sat Apr 13 2002 14:30:00 GMT-0400 (Eastern Daylight Time) · Most importantly eukaryotes…

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