Mighty Mice stay mighty!

Astronauts face a very difficult challenge in space. In microgravity, their muscles and bones weaken over time. Specialized exercise programs developed for stints on the International Space Station (ISS) have helped, but for anything longer—such as a voyage to Mars—they would not be sufficient. In addition, earthbound people with limited or no mobility already face debilitating muscle atrophy and bone fragility, underscoring the need for an effective way to maintain both muscle and bone mass, both here on earth as well as in space.

Myostatin (MSTN) is a protein that is part of a system of checks and balances that limits muscle growth in many species, including humans. When its braking function is removed, increased muscling results. Mice lacking the MSTN gene—dubbed “Mighty Mice”—show dramatic muscle growth. But what happens to these mice in microgravity? And could an inhibitor of MSTN function help even normal, wild-type mice retain their muscle mass in space?

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Mighty Mice in Space Teacher Guide

The JAX Genomic Education team has created a series of lessons that will allow teachers and students to follow the Mighty Mice in Space journey and immerse themselves in the research process. A series of three lessons were created for high school students at the introductory biology level. The lessons are not content driven, but rather emphasize skill development in areas such as prediction, experimental design, data interpretation and graphing. Lessons can be completed individually without any prerequisite knowledge, or given as a set. The teacher guide provides an overview of each lesson and cites additional resources for learning more.

Download the Mighty Mice in Space Teacher Guide

• Lesson 1 Making Predictions - Student Version
• Lesson 2 Analyzing Data - Student Version
• Lesson 3 Research Project
• Lesson 3 PowerPoint Template

An important health mission

On Thursday, December 5, researchers from The Jackson Laboratory for Genomic Medicine (JAX-GM), UConn Health, and Connecticut Children’s sent genetically-engineered “Mighty Mice” to the International Space Station to learn about the effect of microgravity on muscle and bone loss.

The mice were launched at 12:29 p.m. EST on SpaceX’s Dragon spacecraft on a Falcon 9 rocket from Cape Canaveral Air Force Station in Florida. These Mighty Mice are special mice raised by JAX’s custom breeding team in Bar Harbor, Maine, that are genetically engineered to lack myostatin and therefore display approximately twice the average muscle mass. The mice will spend approximately the next 30 days in space to help researcher Se-Jin Lee, M.D., Ph.D., professor at JAX-GM and Presidential Distinguished Professor at UConn School of Medicine, understand the impact of microgravity on muscle and bone degeneration.

JAX Mighty Mice

Over the course of four weeks on the International Space Station (ISS), researchers will determine the effect of microgravity on JAX's Mighty Mice — genetically engineered mice that lack myostatin and therefore display increased muscle mass.

The study will help scientists understand not only how to prevent muscle and bone loss in astronauts during space flight — especially for those on longer missions (Mars, we’re looking to you!), but it will also be tremendously valuable in understanding muscle degeneration in humans on Earth — for example, in elderly populations and those who are bed-ridden, people with rare diseases and those with conditions associated with muscle-wasting.

Se-Jin Lee, M.D., Ph.D. of JAX and UConn Health received a grant from the Center for the Advancement of Science in Space to conduct these experiments onboard the International Space Station (ISS) during the December 2019 - January 2020 mission. The team includes scientists from The Jackson Laboratory, UConn School of Medicine, and Connecticut Children’s Medical Center.

Meanwhile, here on Earth....

In conjunction with the research project on the ISS, JAX is partnering with Weaver High School and Kinsella Magnet School in Hartford, Conn. to involve the next generation of future scientists in this project. High school students will work with our researchers to learn about the importance of mouse models and the International Space Station’s space-based research programs. The students will use data collected at the ISS to develop scientific and data analysis skills aligned with Next Generation Science Standards, and conduct their own independent research projects about muscular and bone degeneration. The students’ work will culminate in a research presentation to scientists at JAX Genomic Medicine in Farmington, Conn.

More about Se-Jin Lee and myostatin

In 1997, aging and disease research hit a tremendous milestone: Professor Lee discovered "myostatin," a molecule involved in regulating muscle growth. Part of a large group of molecules known as the transforming growth factor-beta (TGFß) family, these proteins play diverse roles not just in muscle development, but in a multitude of biological processes, from establishing the body’s basic pattern during the earliest stages of life to guiding the proper form and function of organs like the kidney.