Gene Expression - Epigenetics Effect

Epigenetics Effects

It is a common knowledge that over the past several years a number of studies have been conducted to reveal the effects of epigenetics and to focus fresh attention on its development . Interest to epigenetics was sparked , because better understanding of epigenetics processes and epigenomic would play crucial and important part in understanding genetics and its main aspects as well as in stem cell researches preventing aging processes , cloning opportunities , agriculture evolution , synthetic biology and conservation of species . Therefore epigenetics has a variety of implications in modern scientific

developments (Weinhold 2006

Epigenetics studies epigenetic inheritance defined as a set of reversible heritable changes in gene function or other cell phenotype that occur without a change in DNA sequence known as genotype However , implementation of those changes is likely to be spontaneous and is considered either as response to environmental factors or in response to particular allele . Nevertheless , it is noted that epigenetics differs from epigenesis defined as embryonic morphogenesis and opposed to preformationism

Cellular differentiation plays crucial role in the process of epigenesist and thus it relies entirely on epigenetic inheritance rather than on genetic one . Without epigenetic inheritance no somatic cell cloning would be possible , because normal organism would be unable to recover from differentiated nucleus of the cell . Therefore , cell differentiation is considered epigenetic . It means that somatic cell can be successfully reprogrammed and consequently can become totipotent (Jaenish Bird 2003

It is necessary to note that epigenetics studies effects inherited from one cell generation to the next . Such process occurs in embryonic morphogenesis , tumors , regeneration . Normal cells turnover , culture of cell , replication of organism having only one cell , etc . Recent researches suggest that certain forms of epigenetic inheritance are likely to be maintained even through production of germ cells Consequently , epigenetic inheritance may endure several generations of multi-cellular organisms . Scientists are the most interested in the following epigenetic processes : bookmarking , paramutation , imprinting position effect , gene silencing , gene reprogramming , maternal effects transvection , etc . Furthermore , epigenetic inheritance is able to affect teratogenes and to regulate histone modifications as well as to affect cloning and parthenogenesis (Weinhold 2006

The best known epigenetic process is DNA methylation , partly because it has been the earliest study with existing genetic technology . Chromatic modification is another example of significant epigenetic process Scientists define chromatic as a complex of proteins and DNA bundled into the cell nucleus . Chromatin can be modified by enzymes , acetyla groups and some forms of RNA involving micro- and small RNAs . Such epigenetic modification can alter chromatin structure and thus affect gene expression . Generally , tightly folded chromatin tends to be shut down , or not expressed , while more open chromatin is functional , or expressed (p .28

Nevertheless , the most important epigenetics effect is imprinting Genetics describe imprinting as condition where one of the two alleles of a typical gene pair is silenced by an epigenetic process such as methylation or acetylation (Egger 2004 ) If the expressed allele is seriously damaged , problems may appear , because organisms would be less resistant to...