Red algae of the genus Laurencia are known to biosynthesize and secrete an immense variety of secondary metabolites possessing a spectrum of biological activities against bacteria, invertebrates and mammalian cell lines. Following a rigorous cross-species screening process, herein we report the antifouling potential of 25 secondary metabolites derived from species of the genus Laurencia, as well as the thorough evaluation of the ecotoxicity of selected metabolites against non-target marine arthropods and vertebrate cell lines. A number of these secondary metabolites exhibited potent antifouling activity and performed well in all screening tests. Our results show that perforenol (9) possesses similar antifouling activity with that already described for bromosphaerol, which is used herein as a benchmark.

Reproduction in barnacles relies on chemical cues that guide their gregarious settlement. These cues have been pinned down to several sources of settlement pheromones, one of which is a protein termed Settlement-Inducing Protein Complex (SIPC), a large glycoprotein acting as a pheromone to induce larval settlement and as an adhesive in the surface exploration by the cyprids. Settlement assays in laboratory conditions with Amphibalanus (=Balanus) amphitrite cyprids in the presence of SIPC showed that cyprids exhibit settlement preference behaviour at lower concentrations (EC₅₀=3.73 nM) and settlement avoidance behaviour at higher concentrations of SIPC (EC₅₀=101 nM). By using truncated fragments of SIPC in settlement assays, we identify that domains at the N-terminal of SIPC transduce settlement preference cues that mask the settlement avoidance cues transduced by domains at its C-terminal. Removing the N-terminal 600 amino acids from SIPC resulted in truncated fragments that transduced only settlement avoidance cues to the cyprids. From the sexual reproduction point of view, this bimodal response of barnacles to SIPC suggests that barnacles will settle gregariously when conspecific cues are sparse but will not settle if conspecific cues inform of overcrowding that will increase reproductive competition and diminish their reproductive chances.

The prothoracic gland (PG), the principal steroidogenic organ of insects, has been proposed as a model for steroid hormone biosynthesis and regulation. To validate the robustness of the model, we present an analysis of accumulated transcriptomic data from PGs of two model species, Drosophila melanogaster and Bombyx mori. We identify that the common core components of the model in both species are encoded by nine genes. Five of these are Halloween genes whose expression differs substantially between the PGs of these species. We conclude that the PGs can be a model for steroid hormone synthesis and regulation within the context of mitochondrial cholesterol transport and steroid biosynthesis but beyond these core mechanisms, gene expression in insect PGs is too diverse to fit in a context-specific model and should be analysed within a species-specific framework.

There exists a vast amount of research on how students, in higher education, approach their studying and learning. Such research resulted in a multitude of questionnaires and tools to capture the way students perform in higher education institutions. One of these tools is the Approaches to Study Skills Inventory for Students (ASSIST) that was developed in the ’80 s and ’90 s. This inventory broadly classifies students, as approaching their study, in a deep, a strategic and/or a surface manner. Although it has gone through rigorous validation in many studies, there exist no publicly available dataset of the results of these studies and so the raw datasets cannot be re-used or integrated with other similar datasets. Here, we report and make publicly available the raw data of an 8-year longitudinal survey using this inventory in a cohort study of 1181 students from a department of a higher education institution. We validated our dataset using reliability analyses that confirmed, and compared well, with the results of previous studies.

The cells of prothoracic glands (PG) are the main site of synthesis and secretion of ecdysteroids, the biochemical products of cholesterol conversion to steroids that shape the morphogenic development of insects. Despite the availability of genome sequences from several insect species and the extensive knowledge of certain signalling pathways that underpin ecdysteroidogenesis, the spectrum of signalling molecules and ecdysteroidogenic cascades is still not fully comprehensive. To fill this gap and obtain the complete list of cell membrane receptors expressed in PG cells, we used combinatory bioinformatic, proteomic and transcriptomic analysis and quantitative PCR to annotate and determine the expression profiles of genes identified as putative cell membrane receptors of the model insect species, Bombyx mori, and subsequently enrich the repertoire of signalling pathways that are present in its PG cells. The genome annotation dataset we report here highlights modules and pathways that may be directly involved in ecdysteroidogenesis and aims to disseminate data and assist other researchers in the discovery of the role of such receptors and their ligands.