Abstract
Increasing data show that intronic derived regulatory elements, such as transcription factor binding sites (TFBs), play key roles in gene regulation, and malfunction. Accordingly, characterizing the sequence context of the intronic regions of the human coagulation factor VIII (hFVIII) gene can be important. In this study, the intronic regions of the hFVIII gene were scrutinized based on in-silico methods. The results disclosed that these regions harbor a rich array of functional elements such as repetitive elements (REs), splicing sites, and transcription factor binding sites (TFBs). Among these elements, TFBs and REs showed a significant distribution and correlation to each other. This survey indicated that 31% of TFBs are localized in the intronic regions of the gene. Moreover, TFBs indicate a strong bias in the regions far from splice sites of introns with mapping to different REs. Accordingly, TFBs showed highly bias toward Short Interspersed Elements (SINEs), which in turn they covering about 12% of the total of REs. However, the distribution pattern of TFBs-REs showed different bias in the intronic regions, spatially into the Introns 13 and 25. The rich array of SINE-TFBs and CR1-TFBs were situated within 5'UTR of the gene that may be an important driving force for regulatory innovation of the hFVIII gene. Taken together, these data may lead to revealing intronic regions with the capacity to renewing gene regulatory networks of the hFVIII gene. On the other hand, these correlations might provide the novel idea for a new hypothesis of molecular evolution of the FVIII gene, and treatment of Hemophilia A which should be considered in future studies.