Author Correction: Super-Mendelian inheritance mediated by CRISPR-Cas9 in the female mouse germline.

An Amendment to this paper has been published and can be accessed via a link at the top of the paper.

Super-Mendelian inheritance mediated by CRISPR-Cas9 in the female mouse germline.

A gene drive biases the transmission of one of the two copies of a gene such that it is inherited more frequently than by random segregation. Highly efficient gene drive systems have recently been developed in insects, which leverage the sequence-targeted DNA cleavage activity of CRISPR-Cas9 and endogenous homology-directed repair mechanisms to convert heterozygous genotypes to homozygosity1-4. If implemented in laboratory rodents, similar systems would enable the rapid assembly of currently impractical genotypes that involve multiple homozygous genes (for example, to model multigenic human diseases). To our knowledge, however, such a system has not yet been demonstrated in mammals. Here we use an active genetic element that encodes a guide RNA, which is embedded in the mouse tyrosinase (Tyr) gene, to evaluate whether targeted gene conversion can occur when CRISPR-Cas9 is active in the early embryo or in the developing germline. Although Cas9 efficiently induces double-stranded DNA breaks in the early embryo and male germline, these breaks are not corrected by homology-directed repair. By contrast, Cas9 expression limited to the female germline induces double-stranded breaks that are corrected by homology-directed repair, which copies the active genetic element from the donor to the receiver chromosome and increases its rate of inheritance in the next generation. These results demonstrate the feasibility of CRISPR-Cas9-mediated systems that bias inheritance of desired alleles in mice and that have the potential to transform the use of rodent models in basic and biomedical research.

Prospective study of Candida auris nucleic acids in wastewater solids in 190 wastewater treatment plants in the United States suggests widespread occurrence.

Candida auris is an emerging, multidrug-resistant fungal pathogen that poses a significant public health threat in healthcare settings. Despite yearly clinical cases rapidly increasing from 77 to 8,131 in the last decade, surveillance data on its distribution and prevalence remain limited. We implemented a novel assay for C. auris detection on a nationwide scale prospectively from September 2023 to March 2024, analyzing a total of 13,842 samples from 190 wastewater treatment plants across 41 U.S. states. Assays were extensively validated through comparison to other known assays and internal controls. Of these 190 wastewater treatment plants, C. auris was detected in the wastewater solids of 65 of them (34.2%) with 1.45% of all samples having detectable levels of C. auris nucleic-acids. Detections varied seasonally, with 2.00% of samples positive in autumn vs 1.01% in winter (P < 0.0001). The frequency of detection in wastewater was significantly associated with states having older populations (P < 0.001), sewersheds containing more hospitals (P < 0.0001), and sewersheds containing more nursing homes (P < 0.001). These associations are in agreement with known C. auris epidemiology. This nationwide study demonstrates the viability of wastewater surveillance for C. auris surveillance and further highlights the value of wastewater surveillance when clinical testing is constrained. IMPORTANCE: This study highlights the viability of wastewater surveillance when dealing with emerging pathogens. By leveraging an existing framework of wastewater surveillance, we reveal the widespread presence of C. auris in the United States. We further demonstrate that these wastewater detections are consistent with demographic factors relevant to C. auris epidemiology like age and number of hospitals or nursing homes. As C. auris and other pathogens continue to emerge, the low-cost and rapid nature of wastewater surveillance will provide public health officials with the information necessary to enact targeted prevention and control strategies.

Efficient allelic-drive in Drosophila.

Gene-drive systems developed in several organisms result in super-Mendelian inheritance of transgenic insertions. Here, we generalize this "active genetic" approach to preferentially transmit allelic variants (allelic-drive) resulting from only a single or a few nucleotide alterations. We test two configurations for allelic-drive: one, copy-cutting, in which a non-preferred allele is selectively targeted for Cas9/guide RNA (gRNA) cleavage, and a more general approach, copy-grafting, that permits selective inheritance of a desired allele located in close proximity to the gRNA cut site. We also characterize a phenomenon we refer to as lethal-mosaicism that dominantly eliminates NHEJ-induced mutations and favors inheritance of functional cleavage-resistant alleles. These two efficient allelic-drive methods, enhanced by lethal mosaicism and a trans-generational drive process we refer to as "shadow-drive", have broad practical applications in improving health and agriculture and greatly extend the active genetics toolbox.