Biology subjects

Domingues, R.

Publications and source records attributed to Domingues, R..

5 recordsLinked to original sources

bioRxiv2025

Preservation and remodelling of chloroplast lipids in photosynthetic sea slug host cells

The capacity to retain long-term functional algal chloroplasts within animal cells is a singular trait of some Sacoglossa sea slugs. The stolen chloroplasts (kleptoplasts) confer photosynthetic capacity to the host. This study investigated how chloroplast lipidomes from two macroalgae (Acetabularia acetabulum and Bryopsis sp.) are modified after sequestration by the photosynthetic sea slugs Elysia crispata, Elysia viridis, and Elysia timida. Pigments were analysed by HPLC, and lipidomic profiling of chloroplasts (glycolipids, betaine lipids, phytosterols) was conducted using C18-LC-MS/MS. Kleptoplasts retain intact algal pigment profile. Glycolipid signatures in sea slug tissues closely resembled those of their algal donors, although shifts in relative abundances suggest remodelling of plastidial membranes, potentially affecting kleptoplast morphology, particularly membrane curvature and stability. In contrast, betaine lipid composition differed markedly between sea slugs and algal donors, with major betaine species common to all sea slugs. Phytosterol composition was better preserved in sea slugs feeding on Bryopsis sp. than on A. acetabulum. This study demonstrated that kleptoplast lipidomes maintain a strong algal identity but undergo selective modifications within the animal host. This remodelling likely optimizes membrane architecture to support long-term stability and photosynthetic functionality within the hosts cellular environment, facilitating the integration and performance of sea slug kleptoplasts. HighlightThe lipid profiles of photosynthetic sea slugs resemble the algal donors chloroplasts. However, alterations in glycolipid composition suggest that the molecular architecture of kleptoplasts is modulated by the host cells.

biochemistry↗

bioRxiv2023

The Alzheimer's disease risk gene CD2AP functions in dendritic spines by remodelling F-actin

CD2AP was identified as a genetic risk factor for late-onset Alzheimers disease (LOAD). However, how CD2AP contributes to LOAD synaptic dysfunction underlying AD memory deficits is unclear. We have shown that CD2AP loss-of-function increases {beta}-amyloid (A{beta}) endocytic production, but whether it contributes to synapse dysfunction is unknown. Because CD2AP is an actin-binding protein, it may also function in F-actin-rich dendritic spines, the excitatory postsynaptic compartment. Here, we demonstrate that CD2AP colocalises with F-actin in dendritic spines. Cell-autonomous depletion of CD2AP specifically reduces spine density and volume, with a functional decrease in synapse formation and neuronal network activity. Post-synaptic reexpression of CD2AP but not blocking A{beta}-production is sufficient to rescue spine density. CD2AP overexpression increases spine density, volume, and synapse formation, while a rare LOAD CD2AP mutation induces aberrant F-actin spine-like protrusions without synapses. CD2AP controls postsynaptic actin turnover, with the LOAD mutation in CD2AP decreasing F-actin dynamicity. Our data support that CD2AP risk variants could contribute to LOAD synapse dysfunction by disrupting spine formation and growth by deregulating actin dynamics. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=193 HEIGHT=200 SRC="FIGDIR/small/555707v1_ufig1.gif" ALT="Figure 1"> View larger version (64K): org.highwire.dtl.DTLVardef@160769org.highwire.dtl.DTLVardef@40b903org.highwire.dtl.DTLVardef@1327623org.highwire.dtl.DTLVardef@1ea0f1e_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2023

PhageDPO: Phage Depolymerase Finder

Bacteriophages are the most predominant and genetically diverse biological entities on Earth. They are bacterial viruses which encode numerous proteins with potential antibacterial activity. However, most bacteriophage-encoded proteins have no assigned function, hindering the discovery of novel antibacterial agents. In particular, there has been a growing interest in exploring recombinant bacteriophage depolymerases from the fundamental standpoint, but mostly for biotechnological applications to control bacterial pathogens. Due to the lack of efficient identification tools, we developed PhageDPO, the first developed tool that predicts depolymerases in bacteriophage genomes using machine learning methods. Availability and implementationPhageDPO was integrated into a Galaxy framework available online at: bit.ly/phagedpo.

bioinformatics↗

bioRxiv2022

An electro-optical bead-nanochip technology for the ultrasensitive and multi-dimensional detection of small extracellular vesicles and their markers

Small extracellular vesicles (sEVs), including exosomes, are enriched in multiomics information mirroring their parental cells. They have been investigated in health and disease and utilised in several applications from drug discovery to diagnostics. In disease diagnostics, sEVs can be sampled via a blood draw, enabling the convenient liquid biopsy of the tissue they originate from. However, few applications with sEVs have been translated into clinical practice. We developed a Nanoparticle EXOsome Sensing (NEXOS) technology, for the ultrasensitive and multi-dimensional detection of sEVs. NEXOS comprises two methods: a novel nanoelectronics method, E-NEXOS, and a high-throughput optical detection method, O-NEXOS. Both methods share the same steps for the immunocapture and antibody-labelling of sEVs and can be combined to derive differentiated detection parameters. As a proof of concept, we show the analytical detection and sensitivity of these methods in detecting pre-prepared cancer cell-derived CD9+CD81+ and CD9+HER2+ sEVs. Both sEV populations were diluted in PBS and spiked in processed plasma. We also provide a novel approach for the determination of target sEVs (TEVs), target epitopes in sEVs (TEPs), and epitopes per target sEV, as yet unseen from current and emerging technologies. Further, we demonstrate the higher sensitivity of O-NEXOS compared to the gold standard techniques, as well as demonstrating that E-NEXOS possesses commensurate sensitivity whilst only being powered by 36 nanogap-based sensors per nanochip. Finally, this manuscript lays the groundwork for a scalable electronics miniaturization of E-NEXOS nanochip with millions of nanogap-based sensors for the translation of NEXOS into standard clinical practice.

molecular biology↗

bioRxiv2021

Photosynthesis from stolen chloroplasts increases sea slug reproductive fitness

Some sea slugs are able to steal functional chloroplasts (kleptoplasts) from their algal food sources, but the role and relevance of photosynthesis to the animal host remain controversial. While some researchers claim that kleptoplasts are slowly digestible snacks, others advocate that they enhance the overall fitness of sea slugs much more profoundly. Our analysis show light-dependent incorporation of 13C and 15N in the albumen gland and gonadal follicles of the sea slug Elysia timida, representing translocation of photosynthates to kleptoplast-free reproductive organs. Long-chain polyunsaturated fatty acids with reported roles in reproduction were produced in the sea slug cells using labelled precursors translocated from the kleptoplasts. Finally, we report reduced fecundity of E. timida by suppressing kleptoplast photosynthesis. The present study provides the first thorough experimental evidence that photosynthesis enhances the reproductive fitness of kleptoplast-bearing sea slugs, confirming the biological relevance of this remarkable association between a metazoan and an algal-derived organelle. TeaserSea slugs incorporate functional chloroplasts from algae and use products of photosynthesis to maximize reproductive output.

ecology↗