In this week's Nature Biotechnology, two independent research groups report using CRISPR-Cas9 genome editing to enhance the domestication of wild tomatoes. In the first report, US, German, and Brazilian investigators used the gene-editing technology to introduce certain argonomically beneficial traits of domestic tomatoes into wild tomatoes with desirable nutrition and stress tolerance traits. The work, they write, sets the stage "for molecular breeding programs to exploit the genetic diversity present in wild plants." In the second study, Chinese scientists similarly used CRISPR-Cas9 to add desirable traits into four stress-tolerant wild-tomato accessions. The progeny of their edited plants had "domesticated phenotypes yet retained parental disease resistance and salt tolerance," they write.
Meanwhile, in Nature Plants, investigators from Cornell University and Cold Spring Harbor Laboratory publish a study showing that CRISPR-Cas9 can be used to improve domestication traits in an orphan crop — in this case, a tomato relative called groundcherry. They use genome editing to mutate orthologues of tomato domestication and improvement genes that control plant architecture, flower production, and fruit size in groundcherry, helping to overcome some of the plant's agriculturally undesirable characteristics. "Thus, translating knowledge from model crops enables rapid creation of targeted allelic diversity and novel breeding germplasm in distantly related orphan crops," the researchers write.
And in Nature Genetics, an international research team reports the full-length draft de novo genome assemblies for 16 widely used inbred mouse strains, identifying strain-specific haplotypes and novels functional loci. The team characterized 2,567 regions on the current mouse reference genome exhibiting the greatest sequence diversity, including ones enriched for genes involved in pathogen defence and immunity, as well as regions that exhibit enrichment of transposable elements and signatures of recent retrotransposition events. Allele and gene combinations specific to individual mouse strains were frequently observed at these loci, reflecting the strains' distinct phenotypes. The researchers also used these genomes to build upon the mouse reference genome, resulting in the completion of 10 new gene structures and the addition of 62 new coding loci to the reference genome annotation. GenomeWeb has more on this, here.