Cytoneme signaling provides essential contributions to mammalian tissue patterning. (https://pubmed.ncbi.nlm.nih.gov/38171360/)

These scientists wanted to understand how certain molecules called morphogens help in the development of tissues in our body. Morphogens are like messengers that tell our cells what to do and where to go. But scientists have had a hard time seeing how these morphogens move around in our body because they are very tiny.

So, these scientists came up with a clever way to study this. They created a special mouse that had a problem with delivering a specific morphogen called sonic hedgehog (SHH). They found that a process called endocytic recycling helps in loading SHH into tiny parts of the cells called cytonemes, which are like long arms. These cytonemes help in carrying the SHH to where it needs to go.

To study this in more detail, the scientists used a special microscope and developed new methods to see these cytonemes in action inside the developing mouse's body. They found that the SHH molecule was indeed present in these cytonemes in the mouse's neural tubes, which are important for the development of the nervous system.

When they removed the SHH from these cytonemes, they noticed that the cells in the neural tube didn't develop properly, and this affected the growth of neurons, which are special cells in our brain and nervous system.

The scientists also discovered that a protein called myosin 10 (MYO10) plays an important role in the function of these cytonemes. When they mutated this protein, the cytonemes became shorter and fewer in number, which affected the signaling activity of both SHH and another molecule called WNT.

In conclusion, these results show that these long arms called cytonemes help in spreading the morphogens during the development of tissues in mammals like mice. And the protein MYO10 is important for the proper functioning of these cytonemes.

Hall ET., Dillard ME., Cleverdon ER., Zhang Y., Daly CA., Ansari SS., Wakefield R., Stewart DP., Pruett-Miller SM., Lavado A., Carisey AF., Johnson A., Wang YD., Selner E., Tanes M., Ryu YS., Robinson CG., Steinberg J., Ogden SK. Cytoneme signaling provides essential contributions to mammalian tissue patterning. Cell. 2024 Jan 18;187(2):276-293.e23. doi: 10.1016/j.cell.2023.12.003. Epub 2024 Jan 2.