Clear signals were detected for IRF7 and MyD88 following co-IP of bat MyD88 with bat or human IRF7. There is a slight difference in the molecular weights of human and bat MyD88 and IRF7 which are reflected on the blot. These results clearly demonstrate that bat MyD88 protein is capable of binding both bat and human IRF7 proteins. Confocal microscopy was used to determine the colocalisation of the two proteins, to Caffeic Acid Phenethyl Ester further confirm protein interaction. Bat kidney PaKiT03 cells or human kidney HEK293T cells were used to examine colocalisation of IRF7 with MyD88. A dose of 200 ng/ well of either human or bat MyD88 and IRF7 plasmids were used to transfect cells grown overnight on coverslips in 24-well plates. Sixteen hours later, cells were fixed and stained with anti-human MyD88 antibody and examined under the confocal microscope. MyD88 transfection alone resulted in the formation of very large condensed aggregates in the cytoplasm of both human and bat cells. Human MyD88 and human IRF7 colocalised in a manner similar to previous studies. Similarly, bat MyD88 and IRF7 proteins also demonstrated clear co-localisation. As shown in Figure 6B, bat IRF7 appeared to be surrounded by MyD88 in an aggregated form, which is the typical MyD88 structure. In addition, bat MyD88 also colocalised with human IRF7, which is consistent with our IP results. As expected, no such aggregated structure was observed following co-expression of bat MyD88 with bat IRF3, ruling out the Decoquinate possibility of interaction between these two proteins. IRF7 is a master regulator of IFN expression in mammals and is therefore central to the innate antiviral immune response. In humans, IRF7 acts predominately in pDCs via activation of TLR7/9 and the MyD88 dependent signaling pathway. Regulation of the IFN response may play an important role in the ability of bats to coexist with viruses in the absence of clinical signs of disease. This report describes the analysis of IRF7 from our model bat species, the Australian black flying fox, P. alecto, an important reservoir for viruses including Hendra virus, which has resulted in the deaths of numerous horses and humans since its discovery in 1994.