Cells taken from an FSHD patient were coaxed to become early-stage muscle fibers called myotubes. The cells are labeled for a marker of muscle maturation (green), muscle-cell nuclei (blue) and DUX4 (red).
Protein that plays role in muscle formation identified
Alternative splicing (the process during gene expression that generates multiple proteins from a single gene) plays an important role in many developmental processes. In muscle formation, it has been known that this process occurs in multiple genes when muscle cells called myoblasts fuse to become fibers called myotubes; however, not much is known about the mechanisms that coordinate this process. Researchers at Baylor College of Medicine have now identified a protein Rbfox2 that regulates alternative splicing during this step.
Funding: Funding for the study came from: the American Heart Association (12POST11770017, 11SDG4980011); the Myotonic Dystrophy Foundation; the Ford Foundation; Baylor Research Advocates for Student Scientists (BRASS); the National Institutes of Health (R01HG007538, R01HL045565, R01AR060733, R01AR045653); and the Muscular Dystrophy Association.
The blobfish eyes are formed from Meckel’s cartilage. A component of the first pharyngeal arch that runs the length of the developing mandible. It degenerates as the fetus develops leaving only two small components on each side of the head. These ossify (become bone) to form the incus and malleus (ear ossicles) of the middle ear.
The blobfish nose is the developing tongue. It is composed of developing skeletal muscle fibers. Skeletal muscle forms from myoblasts that line up and fuse to form long myotubes. These will then start to synthesize actin and myosin which will allow them to contract and form the intrinsic skeletal muscle of the tongue.
The blobfish chin is formed by the developing maxilla. Two regions of tissue known as the left and right maxillary prominences grow together and fuse in the midline to form the posterior hard palate. You can see the midline suture forming and feel it in your own mouth by running your tongue along your hard palate. Failure of these prominences to fuse with each other and/or surrounding developing structures results in the development of a variety of cleft lip and palate combinations.
The blobfish head is formed from a developing mandible. You can see small islands of bone forming within the mesenchymal tissue of the head. This type of bone development is unique to the mandible and certain flat bones of the body like those in your skull. It is called intramembranous ossification. T majority of the bones of your skeleton do not form by IO but instead develop from a perfect cartilage model which is gradually replaced by bone as your fetal body develops. This type of bone development is called endochondral ossification.
The blobfish is native to the coastal waters of Australia and Tasmania where it lives way deep down in the darkest depths of the ocean. Its gelatinous body is ideal for withstanding the pressure down there, but when brought to the surface it looks like a sad melted gray crayon.
Prox1 is essential for differentiation of skeletal muscle stem cells called satellite cells. During differentiation satellite cells form long, multinuclear myotubes, but if they lack Prox1 gene, they fail to differentiate. In the figure myosin protein in differentiated myotubes have been stained green. Credit: Riikka Kivelä
Like I said, I got an internship in a lab, I spent two months there doing cell cultures, fluorescence microscopy and a lot of reading. Despite my heart made of stone, I got the urge to cry twice, when I first used the confocal microscope, and when I left it. Actually no, I also almost cried out of frustration when the Leica TCS SP2 bugged out on us and would not work until the end of my internship. Fortunately, we had only a week without a microscope, until we switched to the Olympus FV-1000.
I can’t actually show you any of my work because it’s not published yet. Depending on when it’s actually submitted and when (if) it’s accepted, it might take a while before I can show my beauties. They were C2C12 (muscle) cells, like the ones above, and although they died on me quite a lot, they were a joy to hang around with.
This was Frontal Cortex, anthropomorphising cells since forever.