Comparative biochemical studies of carotenoids in sea urchins—III. Relationship between developmental mode and carotenoids in the Australian echinoids Heliocidaris erythrogramma and H. tuberculata and a comparison with Japanese species

Evolutionary Changes in the Chromatin Landscape Contribute to Reorganization of a Developmental Gene Network During Rapid Life History Evolution in Sea Urchins

Chromatin configuration is highly dynamic during embryonic development in animals, exerting an important point of control in transcriptional regulation. Yet there exists remarkably little information about the role of evolutionary changes in chromatin configuration to the evolution of gene expression and organismal traits. Genome-wide assays of chromatin configuration, coupled with whole-genome alignments, can help address this gap in knowledge in several ways. In this study we present a comparative analysis of regulatory element sequences and accessibility throughout embryogenesis in three sea urchin species with divergent life histories: a lecithotroph Heliocidaris erythrogramma, a closely related planktotroph H. tuberculata, and a distantly related planktotroph Lytechinus variegatus. We identified distinct epigenetic and mutational signatures of evolutionary modifications to the function of putative cis-regulatory elements in H. erythrogramma that have accumulated nonuniformly throughout the genome, suggesting selection, rather than drift, underlies many modifications associated with the derived life history. Specifically, regulatory elements composing the sea urchin developmental gene regulatory network are enriched for signatures of positive selection and accessibility changes which may function to alter binding affinity and access of developmental transcription factors to these sites. Furthermore, regulatory element changes often correlate with divergent expression patterns of genes involved in cell type specification, morphogenesis, and development of other derived traits, suggesting these evolutionary modifications have been consequential for phenotypic evolution in H. erythrogramma. Collectively, our results demonstrate that selective pressures imposed by changes in developmental life history rapidly reshape the cis-regulatory landscape of core developmental genes to generate novel traits and embryonic programs.

Acetylenic Aquatic Anticancer Agents and Related Compounds

Although acetylenes are common as components of terrestrial plants, it is only within the last 30 years that biologically active polyacetylenes having unusual structural features have been reported from aquatic organisms: cyanobacteria, algae, fungi, invertebrates, and other sources. Naturally occurring aquatic acetylenes are of particular interest since many of them display important biological activities and possess antitumor, antibacterial, antimicrobial, antifouling, antifungal, pesticidal, phototoxic, HIV inhibitory, and immuno-suppressive properties. There is no doubt that they are of great interest, especially for the medicinal and/or pharmaceutical industries. This review presents structures and describes cytotoxic and anticancer activities of more than 230 acetylenic metabolites isolated from aquatic organisms. With the computer program PASS some additional biological activities are also predicted, which point toward possible new applications of these compounds. This review emphasizes the role of aquatic acetylenic compounds as an important source of leads for drug discovery.

The effect of sex, season and gametogenic cycle on gonad yield, biochemical composition and quality traits of Paracentrotus lividus along the North Atlantic coast of Portugal

Sea urchin population harvest in the North Atlantic coast of Portugal was characterized in terms of gonad yield, nutritional composition and important market-related traits, over one reproductive cycle (March 2016 to March 2017). Most of the quality attributes showed a seasonal variation strongly dependent on sea urchin sex. Maximum gonad yield (18%) was observed in March 2017. A single spawning event occurred between May and July. Gonads are rich sources of protein (12–18% WW) with low fat content (≤6% WW), that increase during the gametogenic stages of recovery and growing (November-December). Polyunsaturated fatty acids were the dominant class in both sexes (4.2–14.7 mg.g⁻¹ WW), being preferentially accumulated in females. Total gonads carotenoid varied seasonally, with the highest level being observed in males during spawning season. Echinenone was the main pigment present in gonads, showing highest concentrations in males during spawning and gonad recovering. During the growing and early maturation period gonads were more reddish, yellowish and brighter, as well as more firm, irrespectively of the sex. Based on all seasonal changes affecting gonad yield and quality, the period between November and February seems the most suitable to harvest high quality gonads in the Atlantic coast of Portugal.

Are embryonic developing modes determinant in the acquisition and levels of photoprotective compounds in slipper limpets of the Crepipatella genus?

The type of embryonic development (mixed and direct) and its influence on the accumulation and translocation of photoprotective compounds from the mother to the encapsulated embryo was studied in the intertidal gastropods Crepipatella peruviana and Crepipatella dilatata during their reproductive peak. HPLC/MS was used to determine type and levels of sunscreen compounds (total carotenoids; TC/and mycosporine-like amino acid; MAA) in brooding females, capsule walls and early and pre-hatching embryos of both species. Photoprotective compounds were only quantified in nurse eggs of C. dilatata. Our results indicate that females of both species can accumulate TC and MAA at different levels, and they are able to transfer them selectively to capsule walls, embryos and nurse eggs. Palythine-serine (MW=244Da; λmax=320nm) and MAA-330 (MW=234Da; λmax=330nm) constitute total MAA pool in brooding females, whereas brooded embryos incorporate palythine (MW=244Da; λmax=320nm) to the MAA pool. Although TC was transferred from the mother to the embryo through the yolk in both species, MAA trespass showed differences. Females of C. peruviana transfer MAA to their embryos through the embryonic yolk; C. dilatata can transfer MAA only through their nurse eggs, which are consumed by embryos during the terminal stages of intracapsular development. Differences between mixed and direct embryonic development, as well as environmental UV-R levels, which the recently hatched larvae and juveniles of C. peruviana and C. dilatata are exposed to, would determine levels of sunscreen compounds in each species. Higher TC and MAA levels in pre-hatching larvae of C. peruviana compared to C. dilatata, indicate a necessity of C. peruviana for protection against UV-R radiation during approximately 15days when their veliger larvae remain in the water column before metamorphosis is complete. Conversely, low photoprotective levels in pre-hatching juveniles of C. dilatata could be related to low UV-R exposure levels due to the direct incorporation to the benthos and the presence of a protective shell.

Anticancer activity of natural and synthetic acetylenic lipids

This review is a comprehensive survey of acetylenic lipids and their derivatives, obtained from living organisms, that have anticancer activity. Acetylenic metabolites belong to a class of molecules containing triple bond(s). They are found in plants, fungi, microorganisms, and marine invertebrates. Although acetylenes are common as components of terrestrial plants, fungi, and bacteria, it is only within the last 30 years that biologically active polyacetylenes having unusual structural features have been reported from plants, cyanobacteria, algae, invertebrates, and other sources. Naturally occurring aquatic acetylenes are of particular interest since many of them display important biological activities and possess antitumor, antibacterial, antimicrobial, antifouling, antifungal, pesticidal, phototoxic, HIV-inhibitory, and immunosuppressive properties. There is no doubt that they are of great interest, especially for the medicinal and/or pharmaceutical industries. This review presents structures and describes cytotoxic and anticancer activities only for more than 300 acetylenic lipids and their derivatives isolated from living organisms.

Changes of major carotenoids in gonads of sea urchins (Strongylocentrotus intermedius and S. nudus) at maturation

Changes in the carotenoid content in gonads of two sea urchins species were investigated during maturation. The content of echinenones and carotenes, the two major carotenoid fractions in gonads, is highest for Strongylocentrotus intermedius at the spawning gametogenic stage of gonad maturation for both sexes. For S. nudus, the content of these pigments is highest at stages of active gametogenesis and spawning for males and at the growth stage for females. A comparison of the carotenoid content dynamics during maturation of gonads for males, females and animals at the resting (sexual inactivity) stage was also carried out.