Bar Harbor’s Mouse Mecca, By the Numbers

From drug development to medical research, the mice at Jackson Laboratory are advancing science and potentially saving lives.

white mouse
By Peter Andrey Smith
From our April 2023 Animals issue


Strains of research mice offered by Mount Desert Island’s Jackson Laboratory for Mammalian Genetics. Founded in Bar Harbor, in 1929, the lab sold 10 strains in its first commercial catalog (for 10 cents a mouse). Today, Jackson Laboratory, or JAX, offers mouse models both bred and genetically modified. Some strains are kept on ice: for instance, the K18-hACE2 transgenic mouse (strain # 034860) existed as little more than cryogenically frozen sperm when COVID-19 arrived, but reanimating it became critical to understanding humans’ ACE2 receptors, which the coronavirus binds to, causing severe acute respiratory syndrome.


The portion of pharmaceutical companies that use JAX mice to develop and test drugs, according to JAX public relations specialist Cara McDonough. Both basic and applied research — work done by academics in biomedical settings, as well as those doing commercial development — owe a debt to these little-heralded lab animals. Of the U.S.’s four leading vendors of research mice, JAX is the only nonprofit.


Number of JAX mice that lived aboard the International Space Station in 2020, part of a study on muscle growth. It wasn’t the first time the lab’s research mice have achieved liftoff. JAX mice also flew with shuttle crews in earlier efforts to study how space flight affects immunology, bone loss, and the gut microbiome. 


Number of peer-reviewed publications citing the use of JAX mice strains, according to the lab’s marketing materials. In any given month, JAX mice are cited in the fine print of published scientific papers on COVID, cancer, and cochlear implants. They’re named in studies on insulin regulation, opioid addiction, leukemia, and countless other diseases that affect humans. Plug JAX into a search engine for biomedical literature and the citations resemble grains of sand: so numerous and ubiquitous, the total number of citations is difficult to tally. 


How many boxes of mice might leave the JAX loading dock at its busiest, per a shipping manager in a 2008 radio segment (JAX won’t give more recent estimates). The lab ships by ground transport in sterilized, climate-controlled trucks. Caretakers have been known to treat the mice to a soundtrack of classic rock on the loading dock, as the lab finds music keeps them relaxed. These rodents will ultimately be euthanized, but their sacrifice is ideally for the greater good of human understanding, advancing science and potentially saving lives.