Project description:Epoxygoniolide-1 (1), possessing spiroepoxide lactone, enal, and masked dialdehyde functionalities, has been characterized from the conspicuously patterned mollusc Goniobranchus splendidus. Its relative configuration was investigated by spectroscopic analyses, molecular modeling, and density functional theory calculations. The biosynthesis of 1 may involve rearrangement of a diterpene framework, providing a precursor to cometabolite gonioline (2), followed by C-C bond cleavage (via Grob or P450 mechanism). Moderate cytotoxicity to NCIH-460, SW60, or HepG2 cancer cells was observed for norditerpene 1.
Project description:Species identities of Goniobranchus nudibranchs with white bodies and various marginal bands have long been problematic. In this study, specimens of these Goniobranchus nudibranchs from the Philippines, Peninsular Malaysia, Japan, Papua New Guinea, and Madagascar were analyzed and molecular data were obtained in order to re-examine the relationships between species within this "white Goniobranchus with marginal bands" group. The analyses clearly recovered six species groups corresponding to the described species Goniobranchusalbonares, G.preciosus, G.rubrocornutus, G.sinensis, and G.verrieri as well as one new species, G.fabulus Soong & Gosliner, sp. nov. Notably, G.preciosus, G.sinensis, G.rubrocornutus, G.verrieri, and G.fabulus Soong & Gosliner, sp. nov. exhibit color variation and polymorphism, suggesting that some aspects of color patterns (e.g., presence or absence of dorsal spots) may not always be useful in the identification of species in the "white Goniobranchus with marginal bands" group, whereas other features such as gill and rhinophore colors and the arrangement and colors of the mantle marginal bands are more diagnostic for each species.
Project description:Extracts of the mantle and viscera of the Indo-Pacific nudibranchs Goniobranchus aureopurpureus and Goniobranchus sp. 1 afforded 11 new diterpenoids (1-11), all of which possess a tetracyclic spongian-16-one scaffold with extensive oxidation at C-6, C-7, C-11, C-12, C-13, and/or C-20. The structures and relative configuration were investigated by NMR experiments, while X-ray crystallography provided the absolute configuration of 1, including a 2'S configuration for the 2-methylbutanoate substituent located at C-7. Dissection of animal tissue revealed that the mantle and viscera tissues differed in their metabolite composition with diterpenes 1-11 present in the mantle tissue of the two nudibranch species.
Project description:This study aims to investigate the DNA methylation patterns at transcription factor binding regions and their evolutionary conservation with respect to binding activity divergence. We combined newly generated bisulfite-sequencing experiments in livers of five mammals (human, macaque, mouse, rat and dog) and matched publicly available ChIP-sequencing data for five transcription factors (CEBPA, HNF4a, CTCF, ONECUT1 and FOXA1). To study the chromatin contexts of TF binding subjected to distinct evolutionary pressures, we integrated publicly available active promoter, active enhancer and primed enhancer calls determined by profiling genome wide patterns of H3K27ac, H3K4me3 and H3K4me1.
Project description:Whole genome sequencing of the Arabidopsis thaliana dot5-1 transposon insertion line described in Petricka et al 2008 The Plant Journal 56(2): 251-263.