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EPIGENETIC MECHANISMS OF GEN REGULATION

 EPIGENETIC MECHANISMS OF GEN REGULATION

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What Is Epigenetics? metin, ekran görüntüsü içeren bir resim Açıklama otomatik olarak oluşturuldu

• Epigenetics is the study of potentially heritable changes in gene expression (active versus inactive genes) that does not involve changes to the underlying DNA sequence.         • Epigenetik, altta yatan DNA dizisinde değişiklik gerektirmeyen, gen ifadesindeki potansiyel olarak kalıtsal değişikliklerin (aktif ve inaktif genler) incelenmesidir.



• A change in phenotype without a change in genotype — which in turn affects how cells read the genes. • Genotipte bir değişiklik olmadan fenotipte meydana gelen bir değişiklik — bu da hücrelerin genleri nasıl okuduğunu etkiler.

At least seven systems including;

  1. DNA methylation,

  2. Genomic imprinting

  3. X chromosome inactivation

  4. Transpozons

  5. Histone modification/heterochromatin formation/chromatin remodeling,

  6. Non-coding RNA (ncRNA)-associated gene silencing are currently considered to initiate and 

  7. Sustain epigenetic change.

The renewed interest in epigenetics has led to new findings about the relationship between epigenetic changes and disorders including: Epigenetiğe olan ilginin yenilenmesi, epigenetik değişiklikler ve bozukluklar arasındaki ilişki hakkında aşağıdakileri içeren yeni bulgulara yol açmıştır:

  1. various cancers,

  2. mental retardation associated disorders,

  3. immune disorders,

  4. neuropsychiatric disorders and

  5. pediatric disorders.

Cytosine DNA Methylation Marks Genes for Silencing Sitozin DNA Metilasyonu Susturma Genlerini İşaretler

• Generally, genes in which many CG dinucleotide sites are methylated (hypermethylation) tend to be inactive, while genes in which the minority of CG sites are methylated (hypomethylation) tend to be active. • Genel olarak, birçok CG dinükleotid bölgesinin metillendiği genler (hipermetilasyon) inaktif olma eğilimindeyken, CG bölgelerinin azınlığının metillendiği (hipometilasyon) genler aktif olma eğilimindedir.



Phenotypic Consequences of Transposable Elements Transposable Elementlerin Fenotipik Sonuçları

• Transposable elements are DNA sequences that can change its position within a genome and could integrate into the genome at a new site within their cell of origin. • Transpoze edilebilir elementler, bir genom içindeki konumunu değiştirebilen ve köken hücresindeki yeni bir bölgede genomla bütünleşebilen DNA dizileridir.

• Mobile, or transposable, genetic elements and their derivatives are abundant in the genomes of bacteria, plants, and animals. • Mobil veya yeri değiştirilebilen genetik elementler ve bunların türevleri bakteri, bitki ve hayvanların genomlarında bol miktarda bulunur.

• Because they appear to propagate like a parasite in host DNA, transposable elements are sometimes referred as “selfish DNA.” • Konakçı DNA'sında bir parazit gibi çoğaldıkları için, yeri değiştirilebilen elementlere bazen "bencil DNA" denir.

• Movement (transposition) from one place in the genome to another may disrupt genetic function and result in phenotypic variation. • Genomun bir yerinden diğerine hareket (transpozisyon), genetik fonksiyonu bozabilir ve fenotipik varyasyona neden olabilir.


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