Project description:All but the most basal Lepidopteran species produce two sperm morphs. Only one of these morphs is capable of completing karyogamy and producing offspring, this morph contains the correct genetic complement and is termed eupyrene sperm. Apyrene sperm, on the other hand, is completely devoid of nuclear DNA and fertilisation incompetent. Despite the fact apyrene sperm is believed to be functional, the function of this sperm type is largely unknown. Here we apply tandem mass spectrometry based proteomics to the two sperm types independently in the monarch butterfly (Danaus plexippus) and the carolina sphinx moth (Manduca sexta). Comparative analysis between sperm morphs and species shows a reduced complexity and greater divergence in apyrene sperm relative to eupyrene consistent across the two species.
Project description:We characterized sperm from the seminal vesicles of male monarch butterflies (Danaus plexippus), in triplicate, identifying 548 high confidence proteins. As with all but the most basal lepidopteran species male monarch butterflies are sperm heteromorphic, producing fertilization competent and anucleate fertilization incompetent sperm morphs. Comparing this data to the sperm proteomes of the Carolina sphinx moth (Manduca sexta) and the fruit fly (Drosophila melanogaster) demonstrated high levels of functional coherence across proteomes, and conservation at the level of protein abundance and post-translational modification within Lepidoptera. Comparative genomic analyses revealed a significant reduction in orthology among Monarch sperm genes relative to the remainder of the genome in non-Lepidopteran insects. A substantial number of sperm proteins were found to be specific to Lepidoptera, lacking detectable homology outside this taxa. These findings are consistent with a burst of genetic novelty in the sperm proteome concurrent with the origin of heteromorphic spermatogenesis early in Lepidoptera evolution.
Project description:Indisulam is an abandoned drug that acts as a molecular glue, inducing degradation of splicing factor RBM39 through interaction with CRL4DCAF15. We combined indisulam with sphinx 31 (a splicing factor inhibitor) and evaluated their combined activity in inducing splicing errors.
Project description:In many organisms, the circadian clock is composed of functionally coupled morning and evening oscillators that regulate the bouts of dawn and dusk activity. In Arabidopsis, oscillator coupling relies on a core loop in which the evening oscillator component TOC1 was proposed to activate a subset of morning-expressed oscillator genes. Our systems-biological approach overturns the current view of the Arabidopsis circadian clock showing that TOC1 does not function as an activator but as a timely-controlled general repressor of morning and evening oscillator components. Repression occurs through rhythmic binding to the promoters of all oscillator genes, suggesting a previously unexpected direct connection between the morning and evening loops.
Project description:To better understand how diurnal transcriptional regulation contributes to day/night cycles of volatile emission from the petunia flower, cross-linked chromatin from corolla in the morning (7AM) and evening (7PM) was immunoprecipitated with antibodies against 4 histone marks associated with trancriptional activity to determine islands enriched for the marks in morning and evening.
Project description:In many organisms, the circadian clock is composed of functionally coupled morning and evening oscillators that regulate the bouts of dawn and dusk activity. In Arabidopsis, oscillator coupling relies on a core loop in which the evening oscillator component TOC1 was proposed to activate a subset of morning-expressed oscillator genes. Our systems-biological approach overturns the current view of the Arabidopsis circadian clock showing that TOC1 does not function as an activator but as a timely-controlled general repressor of morning and evening oscillator components. Repression occurs through rhythmic binding to the promoters of all oscillator genes, suggesting a previously unexpected direct connection between the morning and evening loops. Examination of TOC1 genome-wide binding using TOC1 Minigene (TMG) seedlings expressing the genomic fragment of TOC1 fused to the Yellow Fluorescent Protein in a toc1-2 mutant background (TMG-YFP/toc1-2 seedlings) grown under LD cycles (12h light:12h dark).