Project description:Poriferans Rift Apart: Molecular sponge biodiversity in Central and French Polynesia and comparison with adjacent marine provinces of the Central Indo-Pacific
Project description:Tropical lagoon-inhabiting organisms live in highly irradiated ecosystems and are particularly susceptible to thermal stress resulting from climate change. However, despite living close to their thermal maxima, stress response mechanisms found in these organisms are poorly understood. We used a novel physiological-proteomic approach for sponges to describe the stress response mechanisms of the lagoon-inhabiting sponge Amphimedon navalis, when exposed to elevated seawater temperatures of +2 oC and +4 oC relative to a 26 oC ambient temperature for four weeks. After four weeks of thermal exposure, the buoyant weight of the sponge experienced a significant decline, while its pumping rates and oxygen consumption rates significantly increased. Proteome dynamics revealed 50 differentially abundant proteins in sponges exposed to elevated temperature, suggesting that shifts in the sponge proteome were potential drivers of physiological dysfunction. Thermal stress promoted an increase in detoxification proteins, such as catalase and glutathione-S-transferase, suggesting that an excess of reactive oxygen species in sponge cells were likely responsible for the significant increase in oxygen consumption. Elevated temperature also disrupted cellular growth and cell proliferation, promoting the loss of sponge biomass, and the high abundance of multiple alpha-tubulin chain proteins also indicated an increase in cytoskeletal activities within sponge cells, which may have induced the increase in sponge pumping rate. Our results show that sustained thermal exposure in susceptible lagoonal sponges may induce significant disruption of cellular homeostasis leading to physiological dysfunction, and that a combined physiological-proteomic approach may provide new insights into physiological functions and cellular processes occurring in sponges.
Project description:Laparoscopic surgery of the distal colon and rectum requires surgery with an appropriate field of view. A commonly used technique to create a clear exposure is the steep Trendelenburg position in which the patient is positioned in an angle of 15 to 40 degrees with the head down using the effect of gravity to retract the small intestine. This method is associated with haemostatic changes caused by the cranial shift of abdominal organs and blood. Recently, a cellulose compressed sponge was developed as intraoperative retractor, with the aim to keep the small intestines aside while the patient remains in a horizontal position. The safety of the sponge is secured with CE marking. The retractor sponge ensures a clear surgical field and potentially prevents haemostatic instability by avoiding Trendelenburg position. A pilot study in the St Antonius Hospital Nieuwegein has shown that use of the sponge might be associated with shorter hospital stay.
Project description:During glyW-cysT-leuZ polycistronic tRNA maturation, the 3’external transcribed spacer (3’ETS) sequence is excised and act as a sRNA sponge (Lalaouna et al., 2015). Using MS2-affinity purification coupled with RNA sequencing (MAPS), we demonstrated that 3’ETSleuZ was highly and specifically enriched by co-purification with at least two different small regulatory RNAs (sRNAs), RyhB and RybB. Both sRNAs were shown to base pair with the same region in 3’ETSleuZ. Here, we use MS2-3’ETSleuZ as bait to co-purify all interacting sRNAs and confirm 3’ETSleuZ/RyhB and 3’ETSleuZ/RybB interactions.
Project description:miRNA sponge, a special class of miRNA target, has been emerging as a pivotal player in miRNA mediated regulatory network. Currently, the identified miRNA sponge genes mostly act on sequestering conserved miRNAs (e.g. miR-7, miR-145), however, the existence, potential function and evolutionary process of miRNA sponge genes for species-specific miRNA, especially for human specific miRNA, are largely unknown. In this study, we conducted a systematic analysis including sponge gene identification and subsequent function and evolutionary analyses for an authentic human-specific miRNA, miR-941.
Project description:In order to compare sponge and eumetazoan (higher animal) body plans, we identified and studied expression of a broad range of eumetazoan developmental regulatory genes in Sycon ciliatum (Calcispongiae). In this species, embryonic development is semi-synchronous within a population, synchronous within individuals, and oocytes and embryos occupy a significant fraction of the volume of the sponges during the reproductive period. RNASeq libraries representing non-reproductive (somatic) tissue slices along the body axis, as well as oocytes, embryos and free swimming larvae were generated from material obtained by sampling throughout the life cycle.