X Kromozomu İnaktivasyonu ve İnaktivasyondan Kaçış

Year 2023, Volume: 32 Issue: 3, 180 - 187, 30.09.2023

Başak Günaştı

https://doi.org/10.17827/aktd.1319050

Abstract

X kromozomunun inaktivasyonu dişi memelilerde iki tane olan X kromozomlarından bir tanesinin inaktive edilmesidir. İnaktivasyona uğrayacak X kromozomu, heterokromatin şeklinde paketlenmektedir. Böylece bu X kromozomunun üzerindeki genlerin eksprese edilmeleri önlenmektedir. İnaktivasyon işlemi, bir adet X kromozomu bulunan erkekler ile iki adet X kromozomu bulunan dişiler arasındaki dengeyi sağlamaktadır. X kromozomu inaktivasyonu, inaktive edilecek tüm X kromozomunda gerçekleştiği düşünülse de, X kromozomunun üzerindeki genlerin tamamı inaktivasyona maruz kalmayıp bir kısmı inaktivasyondan kaçmaktadır. İnsanlarda X kromozomundan kodlanan genlerin yaklaşık %12 ile 20'si kadarı inaktivasyon işleminden kaçarak eksprese olabilmektedir. Derlemede, X inaktivasyonunun mekanizmaları ele alınarak, aktivasyon sürecini ve aktivasyondan kaçan genleri inceleyeceğiz.

Keywords

X kromozomu, X inaktivasyonu, Dozaj telafisi

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