Analyzing the effects of the insertion of an XIST Transgene in a primer explaining “Translating Dosage Compensation to Trisomy 21”
Madison Suess
Department of Biology, University of Minnesota Duluth
Keywords: Down Syndrome, XIST, Barr body, Chromosome 21
Abstract
Down Syndrome, also known as Trisomy 21, affects many worldwide. In fact, 1 in every 700 babies is born with it. This study, “Translating dosage compensation to trisomy 21, ”investigated what would happen to gene expression when X-inactive specific transcript (XIST) was inserted into Chromosome 21 (Jiang et al., 2013). Naturally, XIST is used in the body for the inactivation of one of the X chromosomes in females. It works by
forming a Barr body to prevent overexpression of X-linked genes. The insertion of XIST demonstrated accurate addition to both Chromosome 19 and 21. When added to an extra Chromosome 21 in a cell line, XIST triggered heterochromatin modifications and DNA methylation to form a Barr body. A Barr body is a region that forms on a chromosome that stops gene expression. The insertion of XIST into Chromosome 21 also successfully
silenced the expression from the XIST-carrying chromosome. This showed that the insertion of XIST could be used for future research on Down Syndrome and for research on other trisomy diseases to lessen potential effects of the diseases.
