Volume 228, Issue 2, October 2024

Fluorescent proteins are instrumental in the visualization of gene expression, cell and tissue morphology and developmental processes in the transparent roundworm Caenorhabditis elegans. However, existing red fluorescent proteins (RFP), have very slow maturation times, resulting in significant time before an expressed gene or reporter can be visualized. In this paper, the authors test newly developed RFPs mScarlet3 and mScarlet-I3 in the worm using three different CRISPR-based reporters. They find that these new RFPs offer increased brightness and greatly improved maturation speed, demonstrating the usefulness of these tools to the C. elegans community.

Genomic conflicts involving meiotic drivers are thought to explain the rapid evolution of hybrid male sterility between recently diverged populations. There are, however, few examples directly linking meiotic drive to hybrid sterility. Here, the authors report that the Sex-Ratio chromosome of Drosophila pseudoobscura, which causes X-chromosome drive within the USA subspecies, causes near complete male sterility when moved into the genetic background of the Bogota subspecies.

Di Bernardo and colleagues characterized a previously unidentified SHC family protein, SHC-3, that promotes survival during starvation and heat stress. Like shc-1, shc-3 functions in the Insulin-like signaling pathway, however the two proteins do not act redundantly but rather play distinct roles. In contrast to SHC-1, SHC-3 is not broadly expressed. Its expression in the intestine may suggest that it is required to modify Insulin-like signaling for intestine-specific functions.

Following the pattern of cell divisions in embryos can shed light on essential processes shaping development. While automated cell tracking using fluorescence microscopy is widely available, this requires the generating of transgenic samples. The authors developed embGAN, a software package that can automatically detect cells in 3D imaging using label-free microscopy techniques that don’t require dyes or transgenic samples, making it possible to study the regulation of development in a wider range of animals than previously possible.

The molecular information that controls early development is RNA. Interactions between RNA and RNA binding proteins (RBPs) are critical for successful reproduction across species. In this study, the authors uncovered two roles for the RBP ADR-2 in regulating reproduction. First, they demonstrate that the RNA editing activity of ADR-2 regulates fertility. Next, they screened over 250 other RBPs revealed a genetic interaction between ADR-2 and SQD-1. Further analysis revealed that sqd-1 is essential for the onset of oogenesis, and an editing-independent function of ADR-2 influences proper germline gene expression and oocyte fate in these animals.