Bites: Arm’s length research

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Anatomical drawing showing ligaments and muscles of the arm, 1804

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What’s at the end of your arm? Yes, of course, your hand, your fingers – your fingernails, if you want to get picky. But what about the other end? Where does your arm stop? At your shoulder? What about your shoulder blade? Or does the answer lie even deeper within your body?

Research published in September provided evidence that there is a strong relationship between your arms and anatomical structures inside your abdomen, up to and including your diaphragm.

That was one of a number of findings in a fascinating paper, which was published in Developmental Biology and describes an investigation of how mammals’ forelimbs form. The researchers, funded by the Wellcome Trust and other funders, found that a molecule called Tbx5 is required for the proper formation of the forearm, the upper arm and the skeletal ‘girdle’ that attaches the arm to the body and includes the shoulder blade, collarbone and breastbone. Moreover, Tbx5 is also required for part of the diaphragm to develop properly, suggesting that development of the muscular portion of the diaphragm is linked to the arm through a shared pathway of molecular regulation.

If you thought we had anatomy all sewn up hundreds of years ago, it’s worth reading this paper to see how modern techniques from genetics and developmental biology are deepening our understanding of how the various parts of our bodies grow and relate to each other.

Image credit: Wellcome Library, London.

Reference:

Valasek, P., Theis, S., DeLaurier, A., Hinits, Y., Luke, G., Otto, A., Minchin, J., He, L., Christ, B., Brooks, G., Sang, H., Evans, D., Logan, M., Huang, R., & Patel, K. (2011). Cellular and molecular investigations into the development of the pectoral girdle Developmental Biology, 357 (1), 108-116 DOI: 10.1016/j.ydbio.2011.06.031

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Image may be NSFW.
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