Genomics vs genetics: What’s the difference, and what do they mean for agriculture?

Genomics is an increasingly popular technology used in the agricultural field, but still many don’t quite understand what it is. A common misconception is that genomics is essentially the same as gene editing, but this isn’t quite true. Here we’ll take a look at what these two sciences really are.

Genomics

Genomics is, unsurprisingly, the study of genomes. What’s a genome, though? It’s the entire collection of all the DNA in all the cells of a living thing. The genome contains every patch of DNA — every variant that determines the characteristics of an organism. Every living thing has its own unique genome that determines almost everything about it.

You could say genomics, then, is when scientists read the genome like someone might read a book. They look at all the information contained in the genome and use that information to make determinations about the living thing. It’s a fairly new science — the first organism to have its DNA read, or “sequenced,” was the bacteria Haemophilus influenzae in 1995. To this day, scientists continue to unravel new genomes every year.

In the agricultural field, genomics testing usually lets producers understand the overall health and productivity of an animal based on observations about the DNA responsible for certain traits. Genomics can be used to predict, for example, the milk yield of the offspring of a dairy cow, the ease with which future generations will reproduce, or whether descendants of an animal will be susceptible to specific diseases. The technology can also be used to determine an animal’s parentage.

And what’s the benefit of this? Animal producers and breeders use this information to make selective breeding decisions to improve the likelihood that positive traits remain in their herds, and negative ones fall by the wayside. This allows their herds to become more productive and profitable.

Gene editing

Gene editing, on the other hand, involves more hands-on manipulation of the genome. Scientists can add, remove or alter genetic material at specific places in the genome.

One of the biggest ways scientists do this today is using the CRISPR/Cas9 method, which stands for clustered regularly interspaced short palindromic repeats. You can see why they made an acronym.

This technology mimics a process found in the original gene-editing scientists: bacteria. In this process, bacteria capture snippets of DNA from invading viruses, and use them to create entirely new DNA segments. These segments allow bacteria to maintain a record of the viruses that have attacked them before, so if it happens again, the bacteria can produce RNA segments to target the enemy virus DNA. The bacteria then uses the Cas9 enzyme, or a similar enzyme, to halt the invading DNA.

In the lab, scientists create an RNA segment with a built-in “guide” DNA sequence. The guide sequence binds to a targeted DNA sequence in a specific genome, as well as the Cas9 enzyme. That modified RNA recognizes the DNA segment, and Cas9 cuts the DNA at the targeted location. At this point, scientists take advantage of the cell’s natural ability to repair DNA in order to add, delete, or modify segments of genetic material.

So far, some of the most valuable applications of this technology involve helping animals become disease-resistant. There are many examples of this — this year, researchers, for instance, showed that they had successfully edited a group of pigs to resist the Porcine Reproductive and Respiratory Syndrome virus.

This science is also rather new, and is a bit more controversial than genomics. As the technology continues to develop, our understanding of the best way to use it, too, will continue to develop.