Volume 227, Issue 1, May 2024

Here, Brown et al. describe the “epigenetic toolkit” of two model nematodes: Caenorhabditis elegans and Pristionchus pacificus. Most of the genes and modifications involved in epigenetic regulation are conserved; however, the authors find the histone methyltransferase complex PRC2 is missing in P. pacificus. Despite this, they detect the modification written by PRC2 (H3K27me3), suggesting another enzyme has taken over its function. These results provide a resource for future epigenetic studies and describe the first known loss of PRC2 in an animal.

Population geneticists make inferences about the past by applying statistical models to DNA sequences; however, the decisions made in designing these models have important consequences for inference. Diamantidis et al. explore how the pedigree of a population generated under Wright-Fisher reproduction with no selection but with occasional large reproduction events affects the ancestral genetic process of a sample of size two at a single autosomal locus without recombination, finding that the distribution of pairwise coalescence times conditional on the pedigree converges to a novel limit law as the population size tends to infinity.

Precisely measuring spatial heterogeneity in field experiments is a persistent challenge in crop research. Here, Morales et al. evaluate approaches to improve spatial modeling using high-throughput phenotypes via unoccupied aerial vehicle imagery. The authors test these approaches with simulation data and data from four Genomes-to-Fields hybrid maize field experiments, finding a two-stage approach improves heritability, model fit, and genotypic effect estimation compared to baseline models.