In organisms that propagate by agametic cloning, the parental body is the reproductive unit and fitness increases with clonal size, so that colonial metazoans, despite lack of experimental data, have been considered potentially immortal. Using asexual propagation rate as a measure of somatic performance, and telomerase activity and relative telomere length as molecular markers of senescence, ol...

We studied the effects of pollution in the colonial ascidian Pseudodistoma crucigaster at organismal and suborganismal levels. Our goal was to find early biomarkers to detect some effect of pollution before changes in community structure or species composition occur. We examined the effect of Cu on the production of heat-shock proteins, defence metabolites, growth rates and presence of resistan...

In this chapter we discuss a selection of structurally diverse marine-derived small molecules (MDSMs) with potent and/or specific bioactivity and analyze their biomedical applications. The compounds included have been isolated either from marine macroorganisms, including sponges, ascidians (tunicates), bryozoans, and molluscs, or from microorganisms, such as bacteria and fungi. Our inquiry begi...

The ascidian neural plate exhibits a regular, grid-like arrangement of cells. Patterning of the neural plate across the medial-lateral axis is initiated by bilateral sources of Nodal signalling, such that Nodal signalling induces expression of lateral neural plate genes and represses expression of medial neural plate genes. One of the earliest lateral neural plate genes induced by Nodal signals...

In chordates, neural induction is the first step of a complex developmental process through which ectodermal cells acquire a neural identity. In ascidians, FGF-mediated neural induction occurs at the 32-cell stage in two blastomere pairs, precursors respectively of anterior and posterior neural tissue. We combined molecular embryology and cis-regulatory analysis to unveil in the ascidian Ciona ...

A marine ascidian-associated bacterium, Halobacillus trueperi RSK CAS9, was optimized for lipase production by response surface methodology using marine waste as substrate. The central composite design was employed, and the optimal medium constituents for maximum lipase production (1355.81 U/ml) were determined to be tuna powder (14.58 g/l), olive oil (5.05 ml/l); NaCl (72.42 g/l), temperature ...

The spread of exotic species and climate change are among the most serious global environmental threats. Each independently causes considerable ecological damage, yet few data are available to assess whether changing climate might facilitate invasions by favoring introduced over native species. Here, we compare our long-term record of weekly sessile marine invertebrate recruitment with interann...