Plastid translocon recycling in dinoflagellates demonstrates the portability of complex plastids between hosts.

The plastids of photosynthetic organisms on land are predominantly "primary plastids," derived from an ancient endosymbiosis of a cyanobacterium. Conversely, the plastids of marine photosynthetic organisms were mostly gained through subsequent endosymbioses of photosynthetic eukaryotes generating so-called "complex plastids." The plastids of the major eukaryotic lineages-cryptophytes, haptophytes, ochrophytes, dinoflagellates, and apicomplexans-were posited to derive from a single secondary endosymbiosis of a red alga in the "chromalveloate" hypothesis.

Establishing African genomics and bioinformatics programs through annual regional workshops.

The African BioGenome Project (AfricaBP) Open Institute for Genomics and Bioinformatics aims to overcome barriers to capacity building through its distributed African regional workshops and prioritizes the exchange of grassroots knowledge and innovation in biodiversity genomics and bioinformatics. In 2023, we implemented 28 workshops on biodiversity genomics and bioinformatics, covering 11 African countries across the 5 African geographical regions. These regional workshops trained 408 African scientists in hands-on molecular biology, genomics and bioinformatics techniques as well as the ethical, legal and social issues associated with acquiring genetic resources.

Metabarcoding assessment of fungal diversity in brown algae and sponges of Mauritius.

Marine fungi are largely associated with second most inhabitants of the marine ecosystem such as sponges and algae. They are important colonizers and play vital ecological roles, such as nutrient cycling, organic matter decomposition, and symbiosis with other organisms. High throughput sequencing methods have been used successfully to reveal unknown fungal communities associated with a number of hosts particularly in the marine environment.

A New Dinoflagellate Genome Illuminates a Conserved Gene Cluster Involved in Sunscreen Biosynthesis.

Photosynthetic dinoflagellates of the Family Symbiodiniaceae live symbiotically with many organisms that inhabit coral reefs and are currently classified into fifteen groups, including seven genera. Draft genomes from four genera, Symbiodinium, Breviolum, Fugacium, and Cladocopium, which have been isolated from corals, have been reported. However, no genome is available from the genus Durusdinium, which occupies an intermediate phylogenetic position in the Family Symbiodiniaceae and is well known for thermal tolerance (resistance to bleaching).

Integrated omics unveil the secondary metabolic landscape of a basal dinoflagellate.

Background: Some dinoflagellates cause harmful algal blooms, releasing toxic secondary metabolites, to the detriment of marine ecosystems and human health. Our understanding of dinoflagellate toxin biosynthesis has been hampered by their unusually large genomes. To overcome this challenge, for the first time, we sequenced the genome, microRNAs, and mRNA isoforms of a basal dinoflagellate, Amphidinium gibbosum, and employed an integrated omics approach to understand its secondary metabolite biosynthesis.

Diversified secondary metabolite biosynthesis gene repertoire revealed in symbiotic dinoflagellates.

Symbiodiniaceae dinoflagellates possess smaller nuclear genomes than other dinoflagellates and produce structurally specialized, biologically active, secondary metabolites. Till date, little is known about the evolution of secondary metabolism in dinoflagellates as comparative genomic approaches have been hampered by their large genome sizes. Here, we overcome this challenge by combining genomic and metabolomics approaches to investigate how chemical diversity arises in three decoded Symbiodiniaceae genomes (clades A3, B1 and C).

Two divergent Symbiodinium genomes reveal conservation of a gene cluster for sunscreen biosynthesis and recently lost genes.

Background: The marine dinoflagellate, Symbiodinium, is a well-known photosynthetic partner for coral and other diverse, non-photosynthetic hosts in subtropical and tropical shallows, where it comprises an essential component of marine ecosystems. Using molecular phylogenetics, the genus Symbiodinium has been classified into nine major clades, A-I, and one of the reported differences among phenotypes is their capacity to synthesize mycosporine-like amino acids (MAAs), which absorb UV radiation. However, the genetic basis for this difference in synthetic capacity is unknown.

Multifunctional polyketide synthase genes identified by genomic survey of the symbiotic dinoflagellate, Symbiodinium minutum.

Background: Dinoflagellates are unicellular marine and freshwater eukaryotes. They possess large nuclear genomes (1.5-245 gigabases) and produce structurally unique and biologically active polyketide secondary metabolites.

First record and a new species of Alvinocaris Williams & Chace, 1982 (Crustacea: Decapoda: Caridea: Alvinocarididae) from the Indian Ocean.

A new species of the alvinocaridid shrimp genus Alvinocaris Williams & Chace, 1982 is described from the Solitaire hydrothermal vent field at 2606 m depth on the Central Indian Ridge. Alvinocaris solitaire sp. nov.

α-Glucosidase inhibitory activity of marine sponges collected in Mauritius waters.

This report describes the use of α-glucosidase to evaluate the anti-diabetic potential of extracts from marine sponges collected in the Mauritius waters. Initial screening at 1.0 mg/mL of 141 extracts obtained from 47 sponge species revealed 10 extracts with inhibitory activity greater than 85%.

Evaluation of hexane and ethyl acetate extracts of the sponge Jaspis diastra collected from Mauritius Waters on HeLa cells.

Objectives: Based on previous screening results, the cytotoxic effect of the hexane (JDH) and ethyl acetate extracts (JDE) of the marine sponge Jaspis diastra were evaluated on HeLa cells and the present study aimed at determining their possible mechanism of cell death.

Methods: Nuclear staining, membrane potential change, flow cytometry analysis of cell cycle distribution and annexin V staining were undertaken to investigate the effects of JDE and JDH. Electrospray ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance were used to characterize an isolated bioactive molecule.

High connectivity of animal populations in deep-sea hydrothermal vent fields in the Central Indian Ridge relevant to its geological setting.

Dispersal ability plays a key role in the maintenance of species in spatially and temporally discrete niches of deep-sea hydrothermal vent environments. On the basis of population genetic analyses in the eastern Pacific vent fields, dispersal of animals in the mid-oceanic ridge systems generally appears to be constrained by geographical barriers such as trenches, transform faults, and microplates. Four hydrothermal vent fields (the Kairei and Edmond fields near the Rodriguez Triple Junction, and the Dodo and Solitaire fields in the Central Indian Ridge) have been discovered in the mid-oceanic ridge system of the Indian Ocean.

Ethyl acetate extract of the Mauritian sponge Jaspis sp. induces cell arrest in human promyelocytic leukemia cells.

Marine sponges are considered as a gold mine of new natural products possessing numerous biological activities. We examined the cytotoxic properties of the ethyl acetate extract (JDE) of the previously unrecorded sponge, Jaspis sp. collected from Mauritius Waters.

Acetylcholinesterase-inhibitory activities of the extracts from sponges collected in mauritius waters.

Patients diagnosed with Alzheimer's disease (AD) show a characteristic neurochemical deficit of acetylcholine, especially in the basal forebrains. The use of acetylcholinesterase (AChE) inhibitors to retard the hydrolysis of acetylcholine has been suggested as a promising strategy for AD treatment. In this study, we evaluated the acetylcholinesterase inhibitory (AChEI) activities of 134 extracts obtained from 45 species of marine sponges.

Cytotoxic activities of hexane, ethyl acetate and butanol extracts of marine sponges from Mauritian Waters on human cancer cell lines.

The ocean is an exceptional source of natural products with many of them exhibiting novel structural features and bioactivity. As one of the most interesting phylum with respect to pharmacological active marine compounds, Poriferas have been investigated widely in the last few decades. A total of 60 organic extracts (hexane, ethyl acetate and butanol) from 20 species of marine sponges from Mauritius were screened at 50μg/ml in an in vitro screening assay against 9 human cancer cell lines.

Discovery of new hydrothermal activity and chemosynthetic fauna on the Central Indian Ridge at 18°-20° S.

Indian Ocean hydrothermal vents are believed to represent a novel biogeographic province, and are host to many novel genera and families of animals, potentially indigenous to Indian Ocean hydrothermal systems. In particular, since its discovery in 2001, much attention has been paid to a so-called 'scaly-foot' gastropod because of its unique iron-sulfide-coated dermal sclerites and the chemosynthetic symbioses in its various tissues. Despite increasing interest in the faunal assemblages at Indian Ocean hydrothermal vents, only two hydrothermal vent fields have been investigated in the Indian Ocean.