Volume 229, Issue 4, April 2025

Pilaka-Akella et al. are still learning the code used by the cell to create tissue-specific splicing patterns. Here, using C. elegans, the authors identify UNC-75, a highly conserved RNA binding protein from the CELF family, as a potent repressor of a model tissue-biased exon. UNC-75 regulates exon skipping in neurons by binding to multiple motifs in the introns flanking the exon, and mis-expression of UNC-75 in muscle cells potently represses exon inclusion. Thus, their work sheds further light on RNA processing mechanisms.

Evolution can dramatically change a species. To learn how these changes occur, Harbin et al. study how roundworms became self-fertile. Because this transformation has happened several times, the authors thought that related male/female species would have flexible sexual development. Thus, they used gene editing to study sex in the male/female nematode C. nigoni, a close relative of a self-fertile species. Surprisingly, it shows robust control of all sexual development. Thus, a key step in evolution must be mutations that allow flexibility in development.

New methods for estimating gene genealogies—that is, trees that describe the relationships of gene copies in a sample to each other—have generated excitement among geneticists. However, gene genealogies, and the objects that encode them across the genome, called ancestral recombination graphs, have many features, and it is not obvious how to measure the accuracy of an estimated gene genealogy. Here, Peng et al. conducted a wide variety of simulations to see how errors in gene genealogy estimation affect a specific downstream task.