Dog Gene Editing

Dogs are currently one of the most commonly used laboratory animals in basic medical research and teaching and play an important role especially in experimental studies of physiology, pharmacology, and pathophysiology. Through whole-genome sequencing analysis of dogs, a total of about 19,300 genes have been identified, of which about 18,000 are identical to known human genes, and their genomes are more similar to humans than other laboratory animals such as mice.

Dogs are also very similar to humans in terms of genetic diseases, with more than 360 genetic diseases such as cancer, heart disease, deafness, blindness, and immune nervous system diseases, which are identical to humans and suitable as model animals for humans' disease research.

Moreover, dogs have fewer hereditary diseases, good experimental reproducibility, well-developed blood circulation, and nervous system, digestive system, and internal organs similar to those of humans, and their responses in toxicology are closer to those of humans, especially suitable for research in pharmacology, circulatory physiology, ophthalmology, toxicology, and surgery.

In addition, dogs are docile and easy to train, and they can cooperate well with experiments after short-term training, so they are recognized as ideal model animals in international medical and biological circles.

• Establishment of ASD model dogs

Autism spectrum disorders (ASD) are a group of common neurodevelopmental disorders that are characterized by varying degrees of interaction and communication deficits, narrow interests and repetitive stereotyped behaviors, and perceptual abnormalities, which seriously affect the quality of life of patients and their families. The symptoms are highly heterogeneous from patient to patient, and there is no clear pathological level of detection and no uniform biological markers, only behavioral tests can be used to diagnose this disease.

SHANK3 is the gene associated with ASD, and mutant mouse models are the mainstream way to study the pathogenesis of diseases associated with SHANK3 mutations in humans. However, many genetic disorders in dogs are similar to humans, especially neurological disorders, so we can prepare SHANK3 knockout dogs using CRISPR/Cas9 genome editing technology to establish ASD model dogs.

Figure 1. ASD model dogs were prepared using CRISPR/Cas9 genome editing technology.

• Establishing a diabetic disease model dog

Diabetes mellitus is the third most common disease after cardiovascular disease and tumors, and more than 400 million people worldwide have diabetes mellitus. Among them, Maturity-onset diabetes of the young (MODY) is one of the most prevalent monogenic inherited diabetes, in which MODY2 is caused by inactivating mutations in the GCK gene. A single GCK gene inactivating mutation causes moderate hyperglycemia, while a double inactivating mutation results in severe hyperglycemia and manifests itself at birth.

Since dogs are the best animals for preclinical drug trials and ideal model animals, Lifeasible used CRISPR/Cas9, TALEN and ZFN genome editing technology to establish GCK point mutation diabetic disease model dogs. We constructed a canine MODY2 diabetic disease model that can provide an animal model for the development of MODY2 diabetic stem cell therapy, gene repair therapy, and drug screening, thus providing an important preclinical trial model for the clinical treatment of human MODY2 diabetes.