2019 Year 12 IB Extended Essays

Graph 1 Specificity levels of each researched transcription factor to the heart From the data in the graph alone, it can be seen that the most heart-specific transcription factor is Nkx2.5, with 0 other tisuses expressing similar levels, others include Smyd1, Baf60c and Gata4. On the other hand, 6 other factors are extremely unspecific to the heart, with each having more than 13 other tissue types with higher levels. 4 Discussion The aim of this investigation is to determine which combination of three or four transcription factors will be most suitable to reprogram an adult somatic cell type to cardiomyocytes. The most suitable transcription factor will either have a relatively high specificity of expression to the target cell type, or largely involved in expressing genes that code for proteins involved in vital roles within the cell. From graph 1, it can be seen that Baf60c and Gata4 are both have relatively specific expression in the heart both with only 5 other tissues types having similar levels of expression. However, Baf60c is expressed across all cell types in relatively high levels, and that the reason it being specific to heart cells is because of the level of expression in heart is higher than other tissues. The microarray graph from Amazonia! further supported this conclusion. By showing a certain level of expression of this transcription factor across all cell types, therefore it is not a critical transcription factor that needs to be included in the combination. Similar to Baf60c, Srf, another transcription factor has a medium

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