Here is another pseudocolored desmosome with portions of two mitochondria top and bottom parts of this electron micrograph. It was difficult to determine exactly where the plasmalemma from each of these two cells went at the point of the desmosome, but I thought long and hard about which part of the structure they were. It seemed to me that there was a slight electron lucency just under the plasmalemma on each side, therefore this is the way I pseudocolored (with pink) the cell membranes. The densities within the desmosome itself looks like there are three rows… the central dotted (periodic) line where the cadherin molecules knot together (my guess is this is a totally symmetric arrangement, not at all random like suggested by some) and perhaps another periodicity (well not perhaps…. it is pretty striking) which lies a little separated from the plasmalemma. I don’t know if any of the models of the cadherins show a “lump” structure before the transmembrane part… ? That will take some searching.
Top image is unretouched transmission electron micrograph of a desmosome, as mentioned, mitochondria portion seen top and bottom. The box in this image is what is enlarged in the second image. There are two very prominent intramitochondrial granules, especially the one in the mitochondria at the bottom of the micrograph.
This image is from the boxed area above, thus enlarged, pink is the plasmalemma, orange is the area just under the plasmalemma of each cell and into the space of the desmosome. Blue is what I see as the possible densities of cadherin molecules.
In this inset the periodicity of the outer part of the desmosome (probably still cadherin molecules) is a spacing about 1/15nm not too different from that found in a previous post at something around 1 density for each 13-14nm spacing. The periodicities on the central dense line of the desmosome in this micrograph might be something around 18nm spacing… I would have preferred if the densities came out one-to-one, but anticipate that in other assessments that it might do just that. But for now, i just count what shows up. 6102_5070_mouse_female_control.