Genome scans and elusive candidate genes: detecting the variation that matters for speciation

Next‐generation sequencing is providing us with vast amounts of genetic data, yet we are currently struggling in our attempts to make sense of them. In particular, it has proven difficult to link phenotypic divergence and speciation to genome level divergence. In the current issue of Molecular Ecology, Ruegg et al. ( 2014 ) present new empirical results from two closely related bird taxa. They use a promising approach combining genome scan and candidate gene analysis. Their results suggest that we may have been looking in vain for candidate speciation genes by focusing only on genes found within genomic islands of divergence. This is because genes important in divergence and speciation may not be detected by genome scans and because features of the genomic architecture per se may have a large effect on the pattern of genome divergence.     

Transcription-mediated supercoiling regulates genome folding and loop formation

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Reciprocal allopolyploid grasses (Festuca × Lolium) display stable patterns of genome dominance

Allopolyploidization entailing the merger of two distinct genomes in a single hybrid organism, is an important process in plant evolution and a valuable tool in breeding programs. Newly established hybrids often experience massive genomic perturbations, including karyotype reshuffling and gene expression modifications. These phenomena may be asymmetric with respect to the two progenitors, with one of the parental genomes being “dominant.” Such “genome dominance” can manifest in several ways, including biased homoeolog gene expression and expression level dominance. Here we employed a k-mer–based approach to study gene expression in reciprocal Festuca pratensis Huds. × Lolium multiflorum Lam. allopolyploid grasses. Our study revealed significantly more genes where expression mimicked that of the Lolium parent compared with the Festuca parent. This genome dominance was heritable to successive generation and its direction was only slightly modified by environmental conditions and plant age. Our results suggest that Lolium genome dominance was at least partially caused by its more efficient trans-acting gene expression regulatory factors. Unraveling the mechanisms responsible for propagation of parent-specific traits in hybrid crops contributes to our understanding of allopolyploid genome evolution and opens a way to targeted breeding strategies.     

R-Loop Mediated trans Action of the APOLO Long Noncoding RNA

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The Nuffield Council’s green light for genome editing human embryos defies fundamental human rights law

In July 2018, the Nuffield Council on Bioethics released the report Genome editing and human reproduction: Social and ethical issues, concluding that human germline modification of human embryos for implantation is not ‘morally unacceptable in itself’ and could be ethically permissible in certain circumstances once the risks of adverse outcomes have been assessed and the procedure appears ‘reasonably safe’. The Nuffield Council set forth two main principles governing anticipated uses and envisions applications that may include health enhancements as a public health measure. This essay provides a critique of three aspects in the Nuffield Council’s Report: its presumption of therapeutic efficacy, its inflation of parental rights to create a certain type of child, and its reliance on a specially commissioned report that appears to distort key definitions in international law.