The 21st century has seen repeated challenges to the premise that de novo mutations occur independently from their fitness effects. So far, these attempts have been dismissed as technical artifacts, r...

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Exogenous and endogenous mutagens generate a wide variety of DNA lesions, including bulky adducts, chemical modifications, and single- or double-stranded breaks. A phenomenon called “lesion segregation,” in which lesions evade repair and persist for multiple cell divisions, has recently been documented in tumors and healthy somatic tissues from mice and humans, respectively. Persistent lesions can generate multi-allelic variants (MAVs) by serving as templates for multiple rounds of error-prone replication. By reanalyzing data from a large C. elegans mutagenesis experiment, we observed robust evidence for MAVs at a small fraction (∼0.2%) of mutated sites in the offspring of strains treated with alkylating agents. Because these sequencing data were derived from the progeny of a single F1 animal — itself the offspring of a mutagenized P0 — all mutations should be biallelic. The presence of multi-allelic variation implies that some DNA lesions are transmitted to the F1 zygote, evade repair, and are repeatedly bypassed by error-prone polymerases during embryogenesis. We suspect that many more lesions are inherited than is suggested by MAV prevalence, and that a large fraction of biallelic mutations are also caused by inherited lesions. Our results demonstrate that DNA lesions serve as durable, transgenerational templates for mutagenesis in C. elegans . We speculate that lesion segregation in the early embryo may be a source of mosaicism and genetic diversity in humans, as well. ### Competing Interest Statement The authors have declared no competing interest. National Institutes of Health, https://ror.org/01cwqze88, R01HG012252

Spermatogonial stem cells (SSCs) maintain male fertility, but how their clonal dynamics change with age remains poorly understood. Here, we use in vivo CRISPR barcoding in zebrafish to label SSCs and ...

Methylated CpG sites are saturated for T mutations in a sample of 390K human exomes, providing a test case for inferences about fitness effects in human genes, and insight into the interpretation of m...

GRC presents Function of Evolving Systems, a conference on .

Mutation rates per generation are strikingly similar across germlines of animals and across at least one somatic cell type, suggesting a key role for natural selection in shaping mutation rates. This ...

NIH, NASA grantees are confused and concerned amid agencies’ piecemeal communication

People are born with variable numbers of de novo germline mutations (DNMs), depending primarily on the ages of their parents. To explore additional causes, we developed an approach to call DNMs from nucleotide differences between siblings in genomic regions inherited identical by descent from both parents. Applying it to whole genome sequences from 28,985 sibling pairs of diverse genetic ancestries present in the UK Biobank and All of Us datasets, as well as 2,330 trios, we identified >800K autosomal DNMs and characterized mutation phenotypes in 27,645 sets of parents. We found subtle shifts in the mutation spectrum but no differences in total DNM rates among genetic ancestry groups, or between smokers and non-smokers. Testing for associations between parental mutation phenotypes and their burden of loss-of-function and deleterious missense variants in a set of 180 DNA repair and maintenance genes, we discovered that disruptions in REV1 and LIG1 increase germline mutation rates, and thus that rare mutator alleles segregate in population cohorts. ### Competing Interest Statement The authors have declared no competing interest. NIH, R35 GM083098

Arc Institute’s “MULTI-evolve” learns a classical additive model, not epistasis.

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LINE-1 (L1) retrotransposition generates somatic genomic variation in human cancer, but short-read sequencing has limited our understanding of its structural consequences and dynamics. Using long-read...

The emergence of a chemical system capable of self-replication and evolution is a critical event in the origin of life. RNA polymerase ribozymes can replicate RNA, but their large size and structural ...

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A longstanding goal in human genetics is to prioritize noncoding loci that, when disrupted, lead to developmental disorders and other Mendelian traits. In pursuit of this goal, multiple metrics have been developed to distinguish neutrally evolving sequences from those subjected to purifying selection. These metrics are commonly evaluated genome-wide, e.g., by computing a precision-recall curve on windows tiling the entire noncoding genome. Here, we identify parts of the noncoding genome where these metrics significantly underperform relative to their genome-wide performance due to "bias" in the underlying models of neutral genetic variation and/or a low "signal-to-noise ratio" in the genetic data. The most extreme effects are found for Gnocchi (Chen et al. 2024), the performance of which declines as GC content increases. We suggest annotating constraint scores of noncoding genomic intervals with robust measures of the bias of the corresponding model, allowing users to gauge confidence in those scores. ### Competing Interest Statement The authors have declared no competing interest. National Institutes of Health, R01HG012252

Nature Communications - Genetic predictors of health outcomes often drop in accuracy when applied to people dissimilar to participants of large genetic studies. Here, the authors investigate the...