Suffering major stress through drought may not be an experience farmers value having too often. However, researchers are learning that for animals and plants, such a stressful experience may deliver genetic resilience that helps deliver offspring capable of dealing with such events better in the future.
AgResearch animal genomics team leader Dr Shannon Clarke is heading up research studying the little known but rapidly growing field of methylomes. This research is a study of the natural modification of DNA methylation that happens to all living organisms during development and as a result of that organism experiencing a sustained stressful event.
The science includes studying the heritability of such changes, which in turn improve the organism’s offspring’s ability to cope with such an event in their own lifetime.
Clarke points to the study of epigenetics methylation as a subset of epigenetics. This is the high-profile work conducted by the likes of Sir Peter Gluckman, studying the impact of a mother’s lifestyle and environment upon her child’s future development. Gluckman’s work included research on the links between maternal diet and childhood obesity.
“What we are trying to do with this project is to look paternally two or maternally three generations later at the molecular signature of the DNA to see if it has been passed on from that stressful event, and select better strains for forages or livestock that may be tolerant to drought, for example,” Clarke said.
The work is driven with one eye on the need to accelerate the rate of species adaptation to climate change, while also dovetailing into the demand for future hybrids and breeds that also meet the mandate of helping lower greenhouse gas emissions.
The work is seeking out individual plants and animals that have endured a stressful event over their lifetime, and by default have effectively inoculated future generations against similar events.
“Ultimately, just as you use genomic selection to find the best animals now, you can add this to your selection process,” she said.
Fortunately for the AgResearch team, the research body has a vast library of genetic material from plants and animals from which they can assay the molecular signature of variations bought on by environmental changes.
“This is an invaluable resource the NZ agri sector has, and it has been maintained by AgResearch, so we hit the ground running,” she said.
Meantime, there are also a large number of long-term trials for plants still in the ground, some for over 20 years that will provide valuable material and have often been subjected to significant environmental stress like drought.
While heat tolerance and ability to grow in dry conditions are obvious selectors for climate resilience, facial eczema (FE) is another environmentally inflicted condition researchers would like to study. FE will tend to appear more frequently as conditions heat up throughout more of the country.
The methylome work will also involve studying a sample organism’s chronological age versus its biological age, something along the preoccupation of humans intent on staying younger than they may actually be.
“It could be if the organism looks biologically younger than it is, then they may be capable of living longer and being more productive,” she said.
Clarke says the current project has benefitted by already having the necessary kit and tools to extract the molecular signatures identifying a change.
But she says it is too early to identify what may be first off the rank commercially. However, it could be the longevity selector that drives the first candidates for commercial selection.
“In which case, we could be looking at five to 10 years out,” she said.
In a market-place sensitive to food provenance and purity, the fact this science does not require genetic editing is also a plus.
“This is a natural phenomenon that happens to all living things. And the livestock industry already has these DNA indices on hand, so the information is there to grab,” she said.
