(Received 19 January 2021; revised 27 September accepted 2021) Diplosoma listerianum has been re-described with more than 40 currently invalid names, but recent data suggests that some of those names may be valid. At least four distinct clades were recently revealed by molecular analysis using mitochondrial DNA (mtDNA). Yet, very few samples analyzed from the western Atlantic, which none extens...

What mechanisms underlie aging? One theory, the wear-and-tear model, attributes aging to progressive deterioration in the molecular and cellular machinery which eventually lead to death through the disruption of physiological homeostasis. The second suggests that life span is genetically programmed, and aging may be derived from intrinsic processes which enforce a non-random, terminal time inte...

Formation of the vertebrate neural tube represents one of the premier examples of morphogenesis in animal development. Here, we investigate this process in the simple chordate Ciona intestinalis Previous studies have implicated Nodal and FGF signals in the specification of lateral and ventral neural progenitors. We show that these signals also control the detailed cellular behaviors underlying ...

Biologically active compounds with different modes of action, such as, antiproliferative, antioxidant, antimicrotubule, have been isolated from marine sources, specifically algae and cyanobacteria. Recently research has been focused on peptides from marine animal sources, since they have been found as secondary metabolites from sponges, ascidians, tunicates, and mollusks. The structural charact...

Host monopolization theory predicts symbiotic organisms inhabiting morphologically simple, relatively small and scarce hosts to live solitarily as a result of territorial behaviors. We tested this prediction with Tunicotheres moseri, an endosymbiotic crab dwelling in the atrial chamber of the morphologically simple, small, and relatively scarce ascidian Styela plicata. As predicted, natural pop...

Thanks to their transparent and rapidly developing mosaic embryos, ascidians (or sea squirts) have been a model system for embryological studies for over a century. Recently, ascidians have entered the postgenomic era, with the sequencing of the Ciona intestinalis genome and the accumulation of molecular resources that rival those available for fruit flies and mice. One strength of ascidians as...