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Nine new cerebrosides 1a-d, 2a, 2b, 3a-c were found in the extract of a Far-Eastern glass sponge Aulosaccus sp. (class Hexactinellida). These β-D-glucopyranosyl-(1 → 1)-ceramides contain sphingoid bases (2S,3S,4R,11Z)-2-aminoeicos-11-ene-1,3,4-triol (in 1a-d), (2S,3S,4R,13Z)-2-aminoeicos-13-ene-1,3,4-triol (in 2a, b) and (2S,3S,4R,13S*,14R*)-2-amino-13,14-methylene-eicosane-1,3,4-triol (in 3a-c), which are N-acylated by (2R,15Z)-2-hydroxydocos-15-enoic (in 1a, 2a, 3a), (2R,16Z)-2-hydroxytricos-16-enoic (in 1b, 2b, 3b), (2R,17Z)-2-hydroxytetracos-17-enoic (in 1d) and (2R)-2-hydroxydocosanoic (in 1c, 3c) acids. The monoenoic and cyclopropane-containing sphingoid bases of compounds 1a-d, 2a, 2b, 3a-c have not been found previously in any sphingolipids. The structures of the cerebrosides were elucidated on the basis of (1)H-, (13)C-NMR spectroscopy, mass spectrometry, optical rotation data and chemical transformations. A simplified method for the assignment of the absolute configuration of 2-hydroxy fatty acids by GC analysis of their (2R)- and (2S)-oct-2-yl esters was proposed.

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The purple sea urchin Strongylocentrotus purpuratus has been used for over 150 years as a model organism in developmental biology. Using this model species, scientists have been able to describe, in detail, the mechanisms of cell cycle control and cell adhesion, fertilization, calcium signaling, cell differentiation, and death. Massive parallel sequencing of the sea urchin genome enabled the deciphering of the main components of gene regulatory networks during the activation of embryonic signaling pathways. This knowledge helped to extrapolate aberrations in somatic cells that may lead to diseases, including cancer in humans. Furthermore, since many, if not all, developmental signaling pathways were shown to be controlled by non-coding RNAs (ncRNAs), the sea urchin organism represents an attractive experimental model. In this review, we discuss the main discoveries in the genetics, genomics, and transcriptomics of sea urchins during embryogenesis with the main focus on the role of ncRNAs. This information may be useful for comparative studies between different organisms, and may help identify new regulatory networks controlled by ncRNAs.

Myorod, a new protein of molluscan smooth muscles, is localized on the surface of paramyosin core of thick filaments together with myosin [Shelud'ko et al. (1999) Comp Biochem Physiol, 122, 277]. This protein is an alternatively spliced product of the myosin heavy chain gene. It contains the C-terminal rod part of myosin and a unique N-terminal domain [Yamada et al. (2000) J Mol Biol, 295, 169]. In the present study, the methods of myorod and myorod-free myosin preparation are developed and some properties of myorod are compared with those of myosin and myosin rod. We found that, in spite of the identity of filament-forming domains, the properties of polymeric myorod are clearly distinct from those of myosin and myosin rod. Myorod is much more soluble at intermediate ionic strength. The critical monomer concentration for polymerization of myorod is many times higher. The size of polymer particles of myorod is considerably smaller than that of myosin and myosin rod. The pure polymeric myorod forms a low turbid and unexpectedly high viscous suspension. The low-shear intrinsic viscosity of myorod is an order of magnitude higher than that of myosin or myosin rod and is close to that of F-actin. A trace admixture of myosin in myorod preparations or a small addition of myosin (0.2-1.0%) to myorod drastically alters the myorod polymerization. The suspensions of polymeric myorod nucleated by myosin have a high turbidity and low viscosity and consist of large particles. As judged from the changes in particle size distribution during polymerization, these particles are formed by successive dimerization steps. Electron micrographs show that the particles are typically spindle-shaped filaments in contrast to polymers of pure myorod which forms a network-like structure consisting of small particles. Possible participation of myorod in the catch-contraction of molluscan smooth muscles is discussed.