The main forms of base modifications in DNA and RNA (coding and noncoding RNA) are N6-methyladenosine (m6A) and 5-methylcytosine
(5mC) and its oxidative derivatives 5-hydroxymethylcytosine (5-hmC), 5-formylcytosine (5-fC), and 5-carboxylcytosine (5-caC).
5-hydroxymethylcytosine (5hmC), an oxidised product from 5-methylcytosine
, was also shown to localise to the sites of endogenous DNA damage and promote repair, indicating its role in genomic integrity .
As Figure 1 shows, methylation involves the addition of a methyl group (C[H.sub.3]) to specific cytosines base found in the DNA sequence to produce 5-methylcytosine
The survival rate, 5-methylcytosine
(5-mC) expression, fertilization rate, two-cell rate, and blastocyst rate in vitro were assessed by immunofluorescence and in vitro fertilization.
DNA methylation (5-methylcytosine
) generally represses gene transcription via methyl-binding proteins.
To date, DNA methylation (5-methylcytosine
; "5-mC") is the most-studied epigenetic modification associated with exposure.
Rastegar, "Ethanol deregulates Mecp2/MeCP2 in differentiating neural stem cells via interplay between 5-methylcytosine
and 5-hydroxymethylcytosine at the Mecp2 regulatory elements," Experimental Neurology, vol.
On the other hand, TDG is known to be involved in the removal of T and U mispaired with G, as well as 5-fluorouracil, 5hmU, [epsilon]C, 5-methylcytosine
, 5-formylcytosine, and 5-carboxycytosine bases [19, 38].
mainly occurs among the cytosine-phosphate-guanine (CpG) dinucleotides in regions of densely clustered CpGs, known as CpG islands .
Results: TET proteins, the key enzymes converting 5-methylcytosine
to 5-hydroxymethylcytosine, play vital roles in DNA demethylation regulation.
Recently, we developed an online trapping/ capillary hydrophilic-interaction liquid chromatography/ insource fragmentation/tandem mass spectrometry system for HCC detection by quantifying 5-methylcytosine
(5mC) and 5-hydroxymethylcytosine (5-hmC) in genomic DNA from HCC tumor samples.
Focused, high accuracy 5-methylcytosine
quantitation with base resolution by benchtop next-generation sequencing.