Cytosine methylation and the ecology of intragenomic parasites.
Abstrak
Most of the 5-methylcytosine in mammalian DNA resides in transposons, which are specialized intragenomic parasites that represent at least 35% of the genome. Transposon promoters are inactive when methylated and, over time, C-->T transition mutations at methylated sites destroy many transposons. Apart from that subset of genes subject to X inactivation and genomic imprinting, no cellular gene in a non-expressing tissue has been proven to be methylated in a pattern that prevents transcription. It has become increasingly difficult to hold that reversible promoter methylation is commonly involved in developmental gene control; instead, suppression of parasitic sequence elements appears to be the primary function of cytosine methylation, with crucial secondary roles in allele-specific gene expression as seen in X inactivation and genomic imprinting.
Penulis (3)
J. Yoder
C. Walsh
T. Bestor
Akses Cepat
- Tahun Terbit
- 1997
- Bahasa
- en
- Total Sitasi
- 1999×
- Sumber Database
- Semantic Scholar
- DOI
- 10.1016/S0168-9525(97)01181-5
- Akses
- Open Access ✓