Figure 4. T in Mechanisms of soft tissue and protein preservation in Tyrannosaurus rex

Figure 4. T. rex tissues exhibit positive antibody binding to protein components of extant vascular tissue. (a,c,e,g,i,k,m,o) Are composite images in which fluorescence corresponding to antibody-antigen complexes is overlain upon VLM images of vessel sections, with adjacent images (b,d,f,h,j,l,n,p) captured using a fluorescent filter. (a–d) No spurious binding was observed for negative controls in which vessels were exposed to secondary antibodies raised against the host species of all other antibodies used, i.e., mouse (a,b) and rabbit (c,d). (e,f) Positive binding of dinosaur vessels to actin antibodies can be seen in thin, evenly distributed layers, and (g,h) more broadly distributed binding is apparent for muscle tropomyosin antibodies. Antibodies to both (i,j) type I collagen and (k,l) elastin bind positively to these T. rex vessels. (m,n) Antibodies raised against ostrich haemoglobin exhibit comparatively lower binding intensity. (o,p) No reactivity of dinosaur vessels to antibodies against bacterial peptidoglycan was observed.