Recent studies of endogenous retroviruses have produced a shocking, unrelated result. It is now clear that along with developing the placenta in females, retroviruses are also responsible for the development of stronger muscle mass in males.
About 8% of our gene contains vestiges of past retrovirus genomes. While this number might not seem abnormally large, we need to keep in mind that some of this 8% might still be active encoding proteins in us today.
Syncytins are an example of this, as they had previously been shown to lead to the formation of the placenta in females. This time, the same team of researchers studied male physiology instead and published an important paper in PLOS Genetics that attributed weaker, muscle mass to syncytin-inactivated mice.
Questions to think about:
- Could this knowledge be used to strengthen muscle mass in neuropathic patients?
- Is the muscle development limited to male members of a species? Why?
Redelsperger F, Raddi N, Bacquin A, Vernochet C, Mariot V, Gache V, Blanchard-Gutton N, Charrin S, Tiret L, Dumonceaux J, Dupressoir A, & Heidmann T (2016). Genetic Evidence That Captured Retroviral Envelope syncytins Contribute to Myoblast Fusion and Muscle Sexual Dimorphism in Mice. PLoS genetics, 12 (9) PMID: 27589388