Selective Genomics
There is a way to find out how genomes address functional problems on a whole-genome scale. That way is to select for enhancements of functions using outbred populations. If that selection is sufficiently intense, sufficiently replicated, and sufficiently sustained, it will produce model organisms with genomes that can be analyzed so as to discover the gene-sequence and gene-expression differences that influence the chosen function(s).
The best type of selection to use for this purpose is not the traditional “artificial selection” of quantitative genetics, even though that type of selection has been part of the foundations of agribusiness for decades. Artificial selection requires too much labor to be carried out with sufficient replication for powerful whole-genome analysis.
Instead, Genescient uses experimental evolution. Experimental evolution is based on imposing a general functional requirement on laboratory populations of model organisms, and then letting these populations undergo genetic change at hundreds or thousands of loci. Experimenters do not need to choose particular genes to target, nor do they need to handle the experimental organisms individually.
In the favored Genescient approach, model organisms are selected for reproductive longevity and optimal health over many biological generations. Our most analyzed selected model organism is Drosophila (i.e. fruit flies), which have been selectively bred over three decades. Genescient will soon have data on selected laboratory mice as well.
Lab selected animals can have their functional lifespans, or “healthspans,” increased 2- to 5-fold by sustained selection. In order to extend lifespans and healthspans by that amount, the selected animals need to have their cardiovascular, neurologic, and other metabolic functions greatly “tuned up.” This tuning-up takes place throughout the genome. Genomic sequencing and gene expression chip technologies enable us to identify most of the genes that are associated with this tuned-up state. Because the selected animals are followed over multiple lines Genescient is able to flush out the false changes that occur due to genetic drift.
For more on experimental evolution, see the following: