Changes
no edit summary
<p><span style="font-size:14px"> of the primary DNA sequence and that are heritalbe mitotically and meiotically are classified }</span></p>
<p><u><span style="font-size:14px">## Major two types of epigenemic modifications ##</span></u></p>
<p><span style="font-size:14px">1) <strong>DNA methylation</strong></span></p>
<p><span style="font-size:14px">DNA methylation is the process of by which a methyl group is added to DNA by enzymes <strong>DNA methyltransferases (DNMTs) </strong> which are responsible for catalyzing this reaction. In <u>eukaryotes</u>, methylation is most commonly found on the <u>carbon 5 position of cytosine residues (5mc)</u> adjacent to guanine. DNA methylation patterns vary greatly between species and even with the same organisms. </span></p>
<p><span style="font-size:14px">2) <strong>Histone modification</strong></span></p>
<p> In eukaryotes, genomic DNA is coiled into protein-DNA complexes called chromatin. Histones, which are the most prevalent type of protein found in chromatin, function to condense the DNA; the net positive charge on histones facilitates their bonding with DNA, which is negatively charged. The basic and repeating units of chromatin, nucleosomes, consist of an octamer of histone proteins. Many different types of histone modification are known, including acetylation, methylation, phosphorylation, ubiquitination etc. The DNA region where histone modification occurs can elicit different effects. Histone modifications regulate gene expression by two mechanisms : by disruption of the contact between nucleosomes and by recruiting chromatin remodeling ATPases.</p> <p><u><span style="font-size:14px">## Epigenomic methods ##</span></u></p> <p> </p> <p> </p>
<p><span style="font-size:20px">PROTEOMICS</span></p>