Nav: Home

The making of 'Fancy Mouse'

August 27, 2019

For the past few hundred years, the colorful hair and unique patterns of the so-called "Fancy Mouse" have made them the stars of pet shows in Japan and beyond. Now, scientists have finally revealed the true cause of the genetic mutation responsible for the iconic black pigmentation in the popular East Asian pet.

Their findings were published on August 2, 2019 in Communications Biology.

All mammals possess an "agouti gene," which controls the distribution of melanin pigment that determines the color of hair, skin and eyes. The dominant A allele -- the variant form of a gene that gives rise to specific physical traits -- restricts black pigmentation, and its presence in wild mice results in an "agouti mouse" with a coat comprised of black and yellow banded hairs. "Nonagouti mice," by contrast, possess two a/a alleles due to a hypomorphic mutation of the agouti gene. This mutation causes an almost entirely loss of gene function, resulting in the mouse's coat consisting of only black hair.

In addition to being popular pets, nonagouti mice have been used for a variety of studies into the mechanism and role of pigmentation and the production, storage and distribution of melanin, as well as the link between coat color and behavior.

"Nonagouti mutation is one of the most famous, classical mutations in mouse genetics. Until now, it has been thought that the insertion of a single retrovirus, called VL30, into the gene responsible for expressing hair color is the cause of the nonagouti mutation that results in black coat color in East Asian mice," said study co-author, Tsuyushi Koide, an associate professor in the Mouse Genomics Resource Laboratory at the National Institute of Genetics (NIG), and the Department of Genetics, SOKENDAI (The Graduate University for Advanced Studies) in Japan.

"In our paper, we clarified the true cause of the nonagouti mutation and showed its historical origin. These findings provide a clearer understanding of one of the most well-known mutations in mice," said Koide, who adds that a better understanding of the cause of nonagouti mutation could be useful for many research fields.

In the study, another endogenous retrovirus, known as β4, was found in VL3, and β4, but not VL30, interrupts the agouti gene expression. The researchers used a genome editing technique whereby the genome DNA sequence is efficiently inserted or removed to effect a change or mutation. By using these 'molecular technique' to precisely target and delete the β4 retrovirus located within the VL30 virus on the DNA strand of fertilized mouse eggs that were then inserted into pseudopregnant female mice, the coat color of the neonatal pups was changed from nonagouti (black hairs) to agouti (black and yellow banded hairs). These results show that insertion of a new type of retrovirus β4 into the VL30 retrovirus is the true cause of black coat color, and not the VL30 alone.

After analyzing DNA samples from black (nonagouti) mice as well as a series of wild-derived strains, the researchers also found that the nonagouti trait originated from a line of East Asian mice that were most likely related to Japanese fancy mice.

"We found that the insertion of the β4 retrovirus into VL30 occurred in the lineage of Japanese fancy mice," said Koide. "This mutation was then introduced into a variety of laboratory mice including a standard strain in the early days of mouse genetics."

According to Koide, the insertion of the β4 retrovirus is also found in the gene that causes another type of classical mutation -- piebald coloration -- in mice. "The piebald mutation was also found in the Japanese fancy mice and is known to cause the characteristic black and white piebald pattern," said Koide.

The authors speculated that the β4 retrovirus actively spread within the founder group of Japanese fancy mice. "It will be important to understand when and how β4 was infected into the mouse DNA and the genetic consequences of it amplifying and spreading into several genes that form part of the genetic makeup of the mouse," said Koide.
-end-
About National Institute of Genetics (NIG)

National Institute of Genetics (NIG) was established to carry out broad and comprehensive research in genetics. NIG contributes to the development of academic research as one of the inter-university research institutes constituting the Research Organization of Information and Systems (ROIS).

About the Research Organization of Information and Systems (ROIS)

ROIS is a parent organization of four national institutes (National Institute of Polar Research, National Institute of Informatics, the Institute of Statistical Mathematics and National Institute of Genetics) and the Joint Support-Center for Data Science Research. It is ROIS's mission to promote integrated, cutting-edge research that goes beyond the barriers of these institutions, in addition to facilitating their research activities, as members of inter-university research institutes.

Research Organization of Information and Systems

Related Science Articles:

75 science societies urge the education department to base Title IX sexual harassment regulations on evidence and science
The American Educational Research Association (AERA) and the American Association for the Advancement of Science (AAAS) today led 75 scientific societies in submitting comments on the US Department of Education's proposed changes to Title IX regulations.
Science/Science Careers' survey ranks top biotech, biopharma, and pharma employers
The Science and Science Careers' 2018 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.
Science in the palm of your hand: How citizen science transforms passive learners
Citizen science projects can engage even children who previously were not interested in science.
Applied science may yield more translational research publications than basic science
While translational research can happen at any stage of the research process, a recent investigation of behavioral and social science research awards granted by the NIH between 2008 and 2014 revealed that applied science yielded a higher volume of translational research publications than basic science, according to a study published May 9, 2018 in the open-access journal PLOS ONE by Xueying Han from the Science and Technology Policy Institute, USA, and colleagues.
Prominent academics, including Salk's Thomas Albright, call for more science in forensic science
Six scientists who recently served on the National Commission on Forensic Science are calling on the scientific community at large to advocate for increased research and financial support of forensic science as well as the introduction of empirical testing requirements to ensure the validity of outcomes.
World Science Forum 2017 Jordan issues Science for Peace Declaration
On behalf of the coordinating organizations responsible for delivering the World Science Forum Jordan, the concluding Science for Peace Declaration issued at the Dead Sea represents a global call for action to science and society to build a future that promises greater equality, security and opportunity for all, and in which science plays an increasingly prominent role as an enabler of fair and sustainable development.
PETA science group promotes animal-free science at society of toxicology conference
The PETA International Science Consortium Ltd. is presenting two posters on animal-free methods for testing inhalation toxicity at the 56th annual Society of Toxicology (SOT) meeting March 12 to 16, 2017, in Baltimore, Maryland.
Citizen Science in the Digital Age: Rhetoric, Science and Public Engagement
James Wynn's timely investigation highlights scientific studies grounded in publicly gathered data and probes the rhetoric these studies employ.
Science/Science Careers' survey ranks top biotech, pharma, and biopharma employers
The Science and Science Careers' 2016 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.
Three natural science professors win TJ Park Science Fellowship
Professor Jung-Min Kee (Department of Chemistry, UNIST), Professor Kyudong Choi (Department of Mathematical Sciences, UNIST), and Professor Kwanpyo Kim (Department of Physics, UNIST) are the recipients of the Cheong-Am (TJ Park) Science Fellowship of the year 2016.
More Science News and Science Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Climate Mindset
In the past few months, human beings have come together to fight a global threat. This hour, TED speakers explore how our response can be the catalyst to fight another global crisis: climate change. Guests include political strategist Tom Rivett-Carnac, diplomat Christiana Figueres, climate justice activist Xiye Bastida, and writer, illustrator, and artist Oliver Jeffers.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Speedy Beet
There are few musical moments more well-worn than the first four notes of Beethoven's Fifth Symphony. But in this short, we find out that Beethoven might have made a last-ditch effort to keep his music from ever feeling familiar, to keep pushing his listeners to a kind of psychological limit. Big thanks to our Brooklyn Philharmonic musicians: Deborah Buck and Suzy Perelman on violin, Arash Amini on cello, and Ah Ling Neu on viola. And check out The First Four Notes, Matthew Guerrieri's book on Beethoven's Fifth. Support Radiolab today at Radiolab.org/donate.