By Samantha Kneeskern
January 11, 2016 – Henry David Thoreau once said, “Wildness is the preservation of the World.” And conservation programs help ensure the preservation of plants, animals, wildlife, habitats, and much more. However, there are many challenges associated with protecting threatened wildlife, livestock, and plant populations. First, the populations are small. Secondly, genetic diversity needs to be sustained. Third, the rate of inbreeding needs to be controlled or reduced.
Genomic information and selection can further facilitate this essential preservation. In the January issue of Animal Frontiers, authors Jesús Fernández, Miguel Angel Toro, Fernando Gómez-Romano, and Beatriz Villanueva from Spain explain how genomics can enhance the efficiency of conservation.
“Genomic information gives the advantage that it permits us to know the exact proportion of the genome that is homozygous or that is shared by two individuals, while pedigree information only gives expected proportions,” they write. With this advantage, they can calculate what probability two individuals come from a particular ancestor or lineage.
When populations become endangered in a certain environment, a new “synthetic ex situ” population may need to be created. The overriding goal is to capture the highest level of genetic diversity and to control inbreeding. Computer simulations are being used to optimize diversity level and desired phenotypic trait level.
To maintain genetic diversity, the key method is termed “Optimal Contributions.” These methods optimize the number of offspring to reduce coancestry and also minimize the loss of diversity from one generation to the next. The Optimal Contributions method also controls diversity in specific genomic regions. Because certain genomic regions already have low diversity between the same species, the methods allow scientists to protect those regions.
Another way to improve the efficiency of conservation programs is to eliminate foreign genes. Local, endangered breeds have been crossed with economical and popular mainstream breeds. If there is a loss of the original genetic variants, this may “lead to the loss of local adaptations or valuable disease resistance or quality characteristics,” the authors write. “Thus, in such scenarios, a reasonable objective is to recover the original configuration by removing the genetic contributions from foreign breeds.”
Although there is still more information to be learned on the implementation of genomic tools, genomic techniques can be an excellent substitute for pedigree information, allowing scientists to enhance conservation programs.
To learn more about the mapping techniques and calculations, click here.
About the photo: Iberian pigs (Source: Beatriz Villanueva)