Light sensitivity in Beroidae ctenophores: Insights from laboratory studies and genomics.

Light detection underlies a variety of animal behaviors, including those related to spatial orientation, feeding, avoidance of predators, and reproduction. Ctenophores are likely the oldest animal group in which light sensitivity based on opsins evolved, so they may still have the ancestral molecular mechanisms for photoreception. However, knowledge about ctenophore photosensitivity, associated morphological structures, molecular mechanisms involved, and behavioral reactions is limited and fragmented. We present the initial experiments on the responses of adult Beroe ovata to high-intensity light exposure with different spectra and photosensitivity in various parts of the animal's body. Ctenophores have shown a consistent behavioral response when their aboral organ is exposed to a household-grade laser in the violet spectrum. To investigate the genes responsible for the photosensitivity of Beroidae, we have analyzed transcriptome and genome-wide datasets. We identified three opsins in Beroe that are homologous to those found in Mnemiopsis leidyi (Lobata) and Pleurobrachia bachei (Cydippida). These opsins form clades Ctenopsin1, 2, and 3, respectively. Ctenopsin3 is significantly distinct from other ctenophore opsins and clustered outside the main animal opsin groups. The Ctenopsin1 and Ctenopsin2 groups are sister clusters within the canonical animal opsin tree. These two groups could have originated from gene duplication in the common ancestor of the species we studied and then developed independently in different lineages of Ctenophores. So far, there is no evidence of additional expansion of the opsin family in ctenophore evolution. The involvement of ctenophore opsins in photoreception is discussed by analyzing their protein structures.

Isolation and transcriptome analysis of a biotechnologically promising Black Sea protist, Thraustochytrium aureum ssp. strugatskii.

Background: Marine protists are an important part of the ocean ecosystem. They may possess unique sets of biosynthetic pathways and, thus, be promising model organisms for metabolic engineering for producing substances for the pharmaceutical, cosmetic, and perfume industries. Currently, full-genome data are available just for a limited number of protists hampering their use in biotechnology. Methods: We characterized the morphology of a new cultured strain of Thraustochytriaceae isolated from the Black Sea ctenophore Beroe ovata using phase-contrast microscopy. Cell culture was performed in the FAND culture medium based on fetal bovine serum and DMEM. Phylogenetic analysis was performed using the 18S rRNA sequence. We also conducted a transcriptome assembly and compared the data with the closest species. Results: The protist belongs to the genus Thraustochytrium based on the 18S rRNA sequence analysis. We designated the isolated protist as T. aureum ssp. strugatskii. The closest species with the genome assembly is Schizochytrium aggregatum. Transcriptome analysis revealed the majority of the fatty acid synthesis enzymes. Conclusion: Our findings suggest that the T. aureum ssp. strugatskii is a promising candidate for biotechnological use. Together with the previously available, our data would allow the establishment of an accurate phylogeny of the family Thraustochytriaceae. Also, it could be a reference point for studying the evolution of the enzyme families.

Cascade Transformations of 1-R-Ethynyl-9,10-anthraquinones with Amidines: Expanding Access to Isoaporphinoid Alkaloids.

The interaction of acetamidine and phenylamidine with peri-R-ethynyl-9,10-anthraquinones in refluxing n-butanol leads to the formation of cascade transformations products: addition/elimination/cyclization-2-R-7H-dibenzo[de,h]quinolin-7-ones and(or) 2-R-3-aroyl-7H-dibenzo[de,h]quinolin-7-ones. The anti-inflammatory and antitumor properties of the new 2-R-7H-dibenzo[de,h]quinolin-7-ones were investigated in vivo, in vitro, and in silico. The synthesized compounds exhibit high anti-inflammatory activity at dose 20 mg/kg (intraperitoneal injection) in the models of exudative (histamine-induced) and immunogenic (concanavalin A-induced) inflammation. Molecular docking data demonstrate that quinolinones can potentially intercalate into DNA similarly to the antitumor drug doxorubicin.

Pseudodiaptomus marinus Sato, 1913 in the Black Sea: morphology, genetic analysis, and variability in seasonal and interannual abundance.

Calanoid copepod Peudodiaptomus marinus Sato, 1913 was first recorded in Sevastopol Bay in the northern Black Sea in September 2016. We performed regular observations of this new invasive species between October 2016 and December 2018. We conducted bi-weekly plankton sampling at three stations located within or adjacent to Sevastopol Bay. This is the first paper to combine (i) a detailed morphological study, (ii) molecular genetic analysis, and (iii) an investigation of P. marinus seasonal dynamics and interannual abundance variability in the coastal Black Sea. Our morphological research showed similarities between Pseudodiaptomus specimens and existing P. marinus illustrations and descriptions. Our morphological analysis results were confirmed using molecular genetic studies. Based on the genetic variability of ITS2 and cytb, we found that all investigated specimens from Sevastopol Bay belonged to P. marinus. Investigations of P. marinus seasonal and interannual abundance variability showed the same seasonal patterns throughout the studied period, with a higher seasonal abundance from October to November and one pronounced density peak in autumn. The highest abundances (2,000 ind m-3 at the mouth of the bay and more than 5,000 ind m-3at its centre) were recorded in November 2018. In the samples, we found adults of both sexes, including ovigerous females, copepodites I-V, and nauplii, suggesting that the species reproduce in Sevastopol Bay. Our research indicated that P. marinus is a new non-indigenous species (NIS) in the Black Sea, and we will discuss a possible vector of its introduction into this basin.