Without the bones in my fingers, my typing would look a lot like my toddler’s typing. Asdlijfpoaweif. Today’s image is from a paper looking at bone formation. This paper is a great and satisfying example of story that begins with a developmental question and ends with a cellular mechanism.
Osteoblasts are the cells responsible for generating bone tissue. They are differentiated from mesenchymal stem cells, and a recent paper identifies a role for pannexin 3 in this process. Pannexins are gap junction proteins, which means they form channels that allow material to be exchanged between cells, or between a cell and its extracellular space. On the cellular level, Ishikawa and colleagues found that pannexin 3 serves many purposes in osteoblasts—as a channel for calcium ions on the ER, as a channel for extracellular release of ATP, and as a channel for the exchange of calcium waves between cells. Image above shows a newborn mouse growth plate (left) that is stained for visualization of pannexin 3 (green) and an osteoblast marker (red).
Ishikawa, M., Iwamoto, T., Nakamura, T., Doyle, A., Fukumoto, S., & Yamada, Y. (2011). Pannexin 3 functions as an ER Ca2+ channel, hemichannel, and gap junction to promote osteoblast differentiation originally published in The Journal of Cell Biology DOI: 10.1083/jcb.201101050