Project description:Technology for crosslinking and immunoprecipitation followed by sequencing (CLIP-seq) has identified the transcriptomic targets of hundreds of RNA-binding proteins in cells. To improve the power of existing and future CLIP-seq datasets, we introduce Skipper, an end-to-end workflow that converts unprocessed reads into annotated binding sites using an improved statistical framework. Compared to existing methods, Skipper on average calls 3.1-4.2 times more transcriptomic binding sites and sometimes >10 times more sites, providing deeper insight into post-transcriptional gene regulation. Skipper also calls binding to annotated repetitive elements and identifies bound elements for 99% of enhanced CLIP experiments. We perform nine translation factor enhanced CLIPs and apply Skipper to learn determinants of translation factor occupancy including transcript region, sequence, and subcellular localization. Furthermore, we observe depletion of genetic variation in occupied sites and nominate transcripts subject to selective constraint because of translation factor occupancy. Skipper offers fast, easy, customizable analysis of CLIP-seq data.
Project description:Sperm dimorphism, the production of two distinct sperm morphs by a single male, is a widespread but poorly understood reproductive phenomenon. In Lepidoptera, fertilizing eupyrene sperm coexist with anucleate apyrene sperm, which cannot fertilize eggs but are nevertheless required for successful reproduction. Despite the prevalence and presumed adaptive significance of sperm dimorphism, the molecular basis of this trait remains poorly understood. Here, we characterize the proteome of dimorphic sperm in the Cabbage White butterfly, Pieris rapae, an emerging model for sexual selection and postcopulatory interactions. Using high-resolution, label-free mass spectrometry, we identified more than 1,600 proteins, nearly doubling the number previously reported for other lepidopteran species. Differential abundance analyses revealed eupyrene sperm were enriched for proteins linked to ion transport and vacuolar acidification, while apyrene sperm were enriched for mitochondrial and respiratory functions. Unexpectedly, comparative homology analyses with two other Lepidoptera, Danaus plexippus and Manduca sexta, showed P. rapae shared more homologous sperm proteins with M. sexta than with the more closely related D. plexippus, highlighting complex evolutionary dynamics of sperm proteomes. Together, these findings expand our understanding of sperm function and diversity in Lepidoptera, highlight the distinct roles of eupyrene and apyrene sperm, and provide a foundation for future studies of sperm evolution, sexual selection, and reproductive protein function.
2026-03-23 | PXD070767 | Pride
Project description:Genome skimming of the New Guinea lurcher butterfly Yoma algina (Boiduval, 1832) (Insecta: Lepidoptera: Nymphalidae)