Skip to main content
Premium Trial:

Request an Annual Quote

This Week in Science: May 31, 2019

In Science this week, an international research team publishes a study showing that the duplication of a metabolic gene enabled certain marine fish to adapt to freshwater environments. The diets of marine fish include high levels of docosahexaenoic acid (DHA), an essential omega-3 fatty acid that's lacking in freshwater fish diets. However, certain ocean fish species such as the stickleback were able to adapt to survive in DHA-deficient freshwaters. To understand how this occurred, the researchers examined the stickleback genome and found multiple independent duplications of the fatty acid desaturase gene Fads2 — which is involved in DHA biosynthesis — in stickleback lineages that subsequently colonized and radiated in freshwater habitats. Notably, these duplications are absent in close relatives that failed to colonize freshwaters, and only a single copy of the gene can be found in marine stickleback species.

Also in Science, researchers from the Gladstone Institute of Cardiovascular Research and their colleagues report how a combination of rare, inherited heterozygous mutations can result in a human cardiac disorder. The researchers used whole-exome sequencing on a nuclear family to reveal that offspring with childhood-onset cardiomyopathy inherited three missense single-nucleotide genetic variants from their asymptomatic father and unaffected mother. When the investigators used CRISPR-Cas9 to generate mice with orthologous variants, they found that the compound heterozygosity for all three variants recapitulated the human disease phenotype. GenomeWeb has more on this, here.

And in Science Advances, a team of French researchers publishes a genetic analysis of wheat, offering new insights into the diversification and adaptation of this key agricultural plant since its domestication nearly 10,000 years ago. The group genotyped 4,506 wheat types, including landraces and modern-bred cultivars, from 105 countries using a high-density SNP array. They found that the genetic structure of landraces can be used to trace ancient human migration roads out of the Fertile Crescent west into Europe and east into Asia. They also identify new alleles enriched with structural variations that may be the signature of introgressions from wild relatives after 1960.