Amazing Animals

Let’s Learn From Squirrels!

Squirrels use their gut microbes (microorganisms in their intestines) to maintain their muscle throughout winter. A squirrel's ability to prevent losing muscle mass could guide scientists to help humans suffering from muscular diseases or undernourishment.

So how does it work? Well, when muscles suffer from inactivity, they release nitrogenous compounds (compounds containing a nitrogen atom). Most of the time, the compounds are removed through urination, which is necessary because having too much nitrogen is toxic. But squirrel's gut microbes recover the nitrogen to create amino acids (molecules used to make protein) to refuel their muscles.

Imagine if humans could one day do the same! This would mean athletes who sustain injuries and couldn’t build/retain muscle mass on their own would now be able to.

M.D. Regan et al. Nitrogen recycling via gut symbionts increases in ground squirrels over the hibernation season. Science. Vol 375, January 27, 2022, p. 460-463. DOI: 10.1126/science.abh2950.

Frogs Can Regrow Limbs!

Similar to the discovery with squirrels, scientists have discovered an amazing ability of frogs' that will guide future efforts to help humans! In a study led by Michael Levin, a biologist at Tufts University, a team amputated the hind legs of African Clawed frogs and found something incredible.

Their stumps were treated with five growth-promoting drugs. The scientists attached BioDomes (silicon caps holding a gel containing drugs) to the stumps of the frogs for a day. These drugs encouraged blood vessel, nerve, and muscle tissue growth while also working to stop scarring.

Over the next year and a half, these treated frogs were able to regenerate parts of their bone and develop new nerves and muscles. They wound up growing appendages, knee joints, and even some boneless toes. Although the legs were not fully functioning, they were certainly close. Imagine if people were able to regrow limbs that were lost. I hope we will see many advancements in regenerative medicine due to Levin and his team. Awesome work!!

N.J. Marugan et al. Acute multidrug delivery via a wearable bioreactor facilitates long-term limb regeneration and functional recovery in adult Xenopus laevis. Science. Vol 8, January 26, 2022.  DOI: 10.1126/sciadv.abj2164.