http://www.digitaljournal.com/science/researchers-create-dogs-with-double-muscle-mass/article/447108

Researchers create dogs with double muscle mass

Posted Oct 20, 2015 by Michael Thomas
Chinese researchers have successfully gene-edited dogs with double muscle mass thanks to the CRISPR system, which has also created micropigs and edited human embryos.
A beagle looking out the window (not one of the gene-edited beagles)
A beagle looking out the window (not one of the gene-edited beagles)
Joe deSousa
Gizmodo reports on the breakthrough, detailed in the Journal of Molecular Cell Biology. The super-dogs have two possible uses — to mimic how degenerative diseases affect the human body and, of course, as pets.
The breakthrough came thanks to clustered regularly interspaced short palindromic repeats (CRISPR), a gene-editing tool. To create these strong dogs, researchers attempted to eliminate the myostatin gene — responsible for regulating muscle mass — in 65 beagle embryos. From there, 27 beagles were born but only two showed signs of disruption in the gene.
Researchers named the female beagle Tiangou (a "heaven dog" from Chinese myth) while the male was named Hercules. Tiangou showed a complete disruption of the myostatin gene, while Hercules showed an incomplete disruption, meaning the cell was still producing some myostatin. The dogs' increased muscle mass is easily noticeable in the size of their thigh muscles.
These dogs could have a number of real-world uses besides pets; they could be used by military or police forces, or as hunting dogs. But researchers ultimately want to use CRISPR to mutate dog DNA in other ways and mimic diseases like Parkinson's or muscular dystrophy, which could in turn benefit biomedical research.
"Dogs are very close to humans in terms of metabolic, physiological, and anatomical characteristics," said Liangxue Lai, the study co-author and a researcher at the Key Laboratory of Regenerative Biology at the Guangzhou Institutes of Biomedicine and Health.
This isn't the first time CRISPR has produced novel animal variants. Just a few weeks ago, Chinese researchers were able to create gene-edited micropigs, which will eventually be sold as pets.