Teach with the Do Now Archive This article is part of our archived Do Now activity series. Use the research here to start a classroom conversation around the prompt: Would you buy a genetically engineered pet?

Genetically Modifying Animals

Finding the cutest and best-looking dog or cat is an important part of adopting a new furry friend. So imagine if you could genetically manipulate the traits of an animal to create the ideal pet! Right now, with the assistance of advanced gene modifying programs such as TALENS and CRISPR, genetically modified animals are becoming a reality. Recently, a genomics institute located in Shenzhen, China, called BGI, revealed their genetically modified “micro-pig,” which weighs about 30 pounds when mature. They intend to sell these micro-pigs for $1,600 and, eventually, BGI hopes that customers will be able to “order pigs with customized coat colors and patterns.” The company’s goal is to bring their genetic modifications to a higher level, potentially modifying dog and cat DNA. But no one knows what kind of medical issues will arise from tampering with the genes of an animal. With such little existing research and experience on genetically modifying animals, do we know if it is medically safe - or even ethical - to change a pet’s genome?

The Science

Compared to past techniques, gene editing can be performed much more quickly and efficiently. The price of gene modification has decreased from tens of thousands of dollars to just hundreds of dollars, and these methods have been made public. In the field of genome modification, the two main methods of editing genes are TALENs and CRISPR. These two methods have revolutionized science, providing scientists the chance to conduct revolutionary research---and businesses to create new animal “products.”

The TALENs method uses specially coded enzymes called TALENs to split or cut out specific DNA segments and input new segments of DNA. The TALENs method is very effective because the enzymes can target specific sites where original DNA will be replaced by new segments, overall changing genes. In other words, this program will allow scientists to insert the preferred traits into the DNA of the subject. For example, scientists can replace the brown-eye DNA sequence with a blue-eye sequence, nearly guaranteeing that the animal will have blue eyes.

The other common technique for genome modification is called CRISPR, which stands for “Clustered Regularly Interspaced Short Palindromic Repeats." CRISPR is a natural, adaptive immunity used by select bacteria and archaea to defend against invasive genetic material. CRISPR uses a DNA-snipping enzyme called Cas9, which cuts out specific segments of DNA. Afterwards, new segments are inserted to fill the gaps, overall changing a select gene of a cell. This cell can then divide and multiply through mitosis, creating more cells with the desired traits.

The Debate

The truth is that humans been modifying animals for all of recorded history. Supporters of genetic modification argue that humanity has already been changing animals' genes for thousands of years through selective breeding. When breeders perform selective breeding, allowing only offspring with the desired traits to reproduce, they are controlling the genes that appear in following generations. Is ordering a dog with specific traits from a breeder different than ordering a genetically modified one?