Looks aren't everything?
JAX® NOTES Issue 512, Winter 2008
Gorgeous! Spectacular! Striking! Darling! Those are adjectives commonly used to describe the shiny-, long-, and silky-furred Angora Himalayan Satin mouse. At first glance, the "Angora" might be construed to be the product of "mouse fanciers" — an eclectic group of hobbyists who collect, produce, trade, buy, sell, and exhibit fancy breeds of mice. (Eisen 2005). But, the Angora is not the product of these mouse fanciers. Although its undeniable beauty has not been enough to earn it a JAX® Mice stock number, the Angora was part of a series of experiments that resulted in some of the best mammalian coat color research ever conducted.
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An Angora Himalayan Satin mouse showing off its |
The Angora is a result of a cross made by retired JAX employee Ellie McFarland Starr for Dr. Elizabeth "Tibby" Russell (1913-2001), former JAX research scientist and "one of the truly great figures in the field of mammalian developmental genetics" (Barker and Silvers 2001). When Tibby came to The Jackson Laboratory, she worked on a number of projects to determine the interactive effects of pigment genes. She had Ellie breed mice with various combinations of visual mutations, including those for coat color and coat texture. The locations of these mutations were known and would be used as markers of new mutations. One of the mice produced by Ellie was the "Angora". It was kept after its research value ended, simply because of its rare beauty. The result of Tibby's work was a monumental histological study, published in four parts on the "effect the major coat color mutations of the mouse have on the physical attributes and distribution of pigment granules in the hair. As far as we are aware, this analysis represents the first attempt to define each phenotype of the mouse in terms of the actions and interactions of all the participating factors. It also set the stage for virtually all coat-color studies that followed." (Barker and Silvers 2001).
As far as we know, here at JAX, we maintain the only (and very small) colony of the Angora: currently 11 adults and 20 offspring, ages ranging from just a few days to about seven months. Kristin Cough, Animal Use Trainer at JAX, uses the mice to demonstrate unusual mutations and coat characteristics to her students.
According to Kristin, the mice are not very good moms: "They can be nippy, especially toward their young, and females occasionally stop lactating with a new litter." Kristin often has to remove the pups and place them with foster moms.
The Angora harbors three genes of interest (each of which occurs in other JAX® Mice strains) — satin (Foxg1sa), which confers shiny fur, angora (Fgf5go), which confers long fur, and himalayan (Tyrc-h), the expression of which is cold-activated and confers a dark nose, ears, legs, and tail. Apparently, the himalayan gene functions similarly in mice as it does in cats and rabbits: it darkens the coolest parts of the body to absorb more heat from the sun in cold climates. Kristin has noticed that the Angora Himalayan Satin's appendages lighten up in the summer but darken as the temperature drops in the fall.
The Angora Himalayan Satin mouse seems to have defied the famous axiom that "beauty is only skin deep". Not only has the Angora contributed to the time-tested research of one of JAX's most beloved scientists, it has proven itself as an excellent teaching tool. Who knows what other genetic mysteries this mouse will reveal to us in the future?
References
Barker J, Silvers W. 2001. Elizabeth S. Russell, a biographical memoir. The National Academies Press.
Eisen EJ. 2005. The mouse in animal genetics and breeding research. London: Imperial College Press; Hackensack, NJ: Distributed by World Scientific Pub. Co., 364 pp.
