Biology subjects

Uzbekov, R.

Publications and source records attributed to Uzbekov, R..

5 recordsLinked to original sources

bioRxiv2026

Characterization of ovine follicular fluid and granulosa cell-derived extracellular vesicles and their miRNA cargo following in vitro exposure to bisphenols A and S.

Bisphenol A (BPA) and Bisphenol S (BPS) exposure disrupt ovarian function and granulosa cell (GC) steroidogenesis. Extracellular vesicles (EVs) and their miRNA cargo, as mediators of cellular response to environmental stimuli, might be involved in fertility and folliculogenesis. This study explored modulation of microRNA expression after 48h BPA or BPS exposure (10 {micro}M) in ovine primary GC and EVs from corresponding conditioned medium (CM EVs). Small RNA sequencing of control (0h) and 48h treated GC, CM EVs as well as follicular fluid EVs allowed identification of 533 ovine miRNAs, including 129 new sequences. BPA did not alter miRNA expression in GC, while BPS decreased cellular oar-24b miR. In contrast, BPA modified expression of 4 miRNAs in CM-EVs, including 3 new sequences, and two miRNAs were modified by BPS. Both compounds reduced expression of sequence homologous to miR-1306. Further studies are required to decipher their roles in bisphenol toxicity in GC.

molecular biology↗

bioRxiv2024

Gone but not forgotten: dynamics of sperm storage and potential ejaculate digestion in the black soldier fly Hermetia illucens

When it comes to describe reproduction in internally fertilized species, understanding the dynamics of sperm storage is crucial to unravel the complexity of post-copulatory sexual selection processes. This physiological process goes from sperm transfer to its use for fertilization. In this framework, the spatiotemporal dynamics of sperm storage were described in the black soldier fly (BSF) with fluorescence and transmission electron microscopy (TEM). Besides being of great economic interest, BSF females have highly compartmentalized spermathecae. Spermatozoa were counted both during and after mating in two successive spermathecae compartments: the fishnet canals and the reservoirs. In addition to seminal fluids, male transfers a sperm plug in the fishnet canals, then only some spermatozoa reach the reservoirs over 2 days. TEM observations of the fishnet canals revealed potential digestive functions, explaining the decline in the number and the viability of spermatozoa that have not been stored in the reservoirs. After one mating, females laid up to three fertile clutches, evidencing no constraints on sperm quantity or quality. Spermatic and ultrastructural investigations strongly suggest that BSF ejaculate acts both as a sperm plug and a as nuptial gift, reinforcing the interest in studying this insect as a model for sexual selection.

evolutionary biology↗

bioRxiv2023

Discovery of new endogenous viral elements in campoplegine wasps (Ichneumonidae, Campopleginae, Campoplex) suggests a widespread nudivirus domestication event

Viral endogenization events in the genomes of parasitoid wasps have led to the production of immunosuppressive particles that are injected into the host and that either contain DNA encoding virulence effectors or virulence proteins, essential for parasitism success. In some Campopleginae (Ichneumonidae) wasps, viral endogenisation involves the production of large dsDNA ichnoviruses encoding several dozens of rep virulence genes, to the exception of Venturia canescens. Instead, V. canescens harbours an endogenous nudivirus producing Virus-Like-Particles (VLPs) in which virulence proteins are wrapped into viral envelopes. Here, we described that this nudiviral domestication event is more ancient and widespread than previously thought as we identified homologous alphanudivirus sequences in the genomes of three Campopleginae species belonging to the genera Campoplex and Rimphoctona. We showed that Campoplex capitator produces morphologically similar VLPs to those of V. canescens with almost the same viral protein content. Strikingly, the virulence proteins are however different, suggesting that VLPs allow a high versatility in the molecular strategies used by the wasps in response to host selection pressures. Furthermore, a marked expansion of serpin and rep genes is present in Campoplex capitator, with one serpin and several REP proteins identified as major VLP components using proteomics. REP proteins are also well-described virulence factors initially shown to be delivered into hosts via the expression of rep genes coded by ichnovirus DNA. In Campoplex capitator, these proteins are packaged into nudivirus-derived VLPs indicating that convergent use of virulence factors can imply endogenous viruses of different origin and with different delivery mechanisms.

evolutionary biology↗

bioRxiv2022

Centrosome formation in the bovine early embryo.

Centrosome formation during early development in mice and rats occurs due to the appearance of centrioles de novo. In contrast, in humans and other non-rodent mammals, centrioles are thought to be derived from spermatozoa. Ultrastructural study of zygotes and early embryos of cattle at full series of ultrathin sections showed that the proximal centriole of the spermatozoon disappears by the end of the first cleavage division. Centrioles appear in 2-4 cell embryos in fertilized oocytes and in parthenogenetic embryos. Centriole formation includes the appearance of atypical centrioles with randomly arranged triplets and centrioles with microtubule triplets of various lengths. After the third cleavage, four centriolar cylinders for the first time appear in the blastomeres while each embryo still has two atypical centrioles. Our results showed that the mechanisms of centriole formation in different groups of mammals are universal, differing only in the stage of development in which they occur.

cell biology↗

bioRxiv2021

A novel domain within the CIL regulates egress of IFITM3 from the Golgi and prevents its deleterious accumulation in this apparatus

The InterFeron-Induced TransMembrane proteins (IFITMs) are broad viral inhibitors that protect cells by preventing viral-to-cellular membrane fusion and they belong to the dispanin/CD225 family that includes vesicle trafficking regulators and proteins of unknown functions into four subfamilies (A-D). In this study, we uncover a novel domain that regulates the egress of IFITM3 from the Golgi and that is required to prevent IFITM3-driven v- to t-SNAREs membrane fusion inhibition and Golgi dysfunctions. The S-x-K-x-R-D domain is conserved among vertebrate members of the dispanin/CD225 A subfamily that regroups all IFITMs and through the study of mutations identified in patients affected by paroxysmal kinesigenic dyskinesia (PKD), we determine that it is functionally conserved also in PRRT2, member of the B subfamily. Overall, our study defines a novel domain that regulates the egress of dispanin/CD225 members from the Golgi and stresses the importance that regulation of this process bears to preserve the functions of this apparatus.

cell biology↗