Sex-Specific Developmental Gene Expression Atlas Unveils Dimorphic Gene Networks in C. elegans

Sex-specific traits and behaviors are facilitated by the acquisition of unique properties in the nervous system of each sex during development and continues in adulthood. However, the genetic events responsible for introducing these sex-specific features remain poorly understood. In this study, we created a comprehensive gene expression atlas for both sexes of the nematode Caenorhabditis elegans across development. By comparing the transcriptome of pure populations of hermaphrodites and males from early larval stages to adulthood, we discovered numerous differentially expressed genes, including neuronal gene families like transcription factors, neuropeptides, and GPCRs. We identified INS-39, an insulin-like peptide, as a prominent male-biased gene expressed specifically in ciliated sensory neurons. We show that INS-39 serves as an early-stage male marker, facilitating the effective isolation of males in high-throughput experiments. Analysis of ins-39 knock out animals revealed pleiotropic sex-specific roles in temperature sensation, survival in cold temperatures, resilience against high hydrogen peroxide levels, and dauer entry, while also playing a shared, dimorphic role in early life stress. This study offers a comparative sexual and developmental gene expression database for C. elegans, which will facilitate research into the genetic regulation of the sexual development of other organisms. Furthermore, it highlights conserved candidate genes that may underlie the sexually-dimorphic manifestation of different human diseases Whole animal RNA-seq profiles from five developmental stages (L1, L2, L3, L4 and YA) from nematode N2 wild-type and dpy-28(y1);him-8(e1489) strain of Caenorhabditis elegans grown at 25oC. N2 wild-type strain of Caenorhabditis elegans were all hermaphrodite while dpy-28(y1);him-8(e1489) strain of Caenorhabditis elegans were >98% males. (each group has four biological repeats). Totaling 40 samples (10 groups with four biological repeats). To compare the transcriptome of pure populations of hermaphrodites and males from early larval stages to adulthood (L1, L2, L3, L4 and YA) in both sexes (hermaphrodites and males) of nematode Caenorhabditis elegans.