In Science Express this week, a team led by researchers at the University of California, Davis, report new details about the origin of de novo genes. They compared the gene expression in Drosophila melagonaster with that in a population of uncharacterized inbred flies. They identified 106 fixed and 146 polymorphic de novo genes in the inbred fly strain that were non-genic in other fly strains, but also identified similarity to the genetic content in the equivalent region of the flies’ genomes. The genes are thought to derive primarily from ancestral intergenic, unexpressed open reading frames, with natural selection playing a "significant role" in their spread.
Over in Science, the Wellcome Trust's Elizabeth Murchison and her colleagues report that they have sequenced the genomes of two canine transmissible venereal tumors. They isolated and sequenced DNA from the tumors and their hosts, an Aboriginal camp dog and an American cocker spaniel. From this, they found that CTVTs have amassed some 1.9 million somatic substitution mutations and show evidence of being exposed to ultraviolet light. And though the tumor contains numerous rearrangements, variation in copy number, and retrotransposon insertions, Murchison and her colleagues report that it is stable and does not exhibit subclonal heterogeneity. They also calculated that the dog from which this transmissible tumor arose lived some 11,000 years ago.
Also in Science, two researchers provide a review of the burgeoning field of paleogenomics, highlighting the need for improved technologies to extract DNA from fossils and sequencing ancient genomes to high coverage. They also note that ongoing improvements in DNA isolation and dropping sequencing costs is enabling the rapid expansion of paleogenomics — something that will continue with the improved capacity to screen large numbers of samples for those with high proportions of endogenous ancient DNA.
Additionally, Harvard Medical School's George Church and colleagues argue that people who contribute samples to biobanks should have access to their raw data. Such a move, they add, would make research participants more active in the process and acknowledge their agency and provide the "freedom to decide, option of independent analysis, and informed decision about participation."