Biology subjects

Revel, M.

Publications and source records attributed to Revel, M..

5 recordsLinked to original sources

bioRxiv2025

Characterization of the Post-Mating Responses of Drosophila hydei, a species that lacks Sex-Peptide.

Female post-mating responses (PMRs) in Drosophila melanogaster rely on proteins made by the male that are transferred to the female upon mating to modify her behavior and physiology. Many of the most characterized responses are initiated by a single protein produced by the male accessory gland called the Sex Peptide (SP). Yet many Drosophila species, even those living in similar environments, do not have SP. As PMRs are thought to be mechanisms used to maximize reproductive success, we wondered if PMRs are similar in species living in the same environment and how PMRs might be achieved in species that lack SP. Here, we investigate the post-mating responses of D. hydei. D. hydei is a Drosophilid that lacks SP, but is often found cohabitating with D. melanogaster. We show that the PMR in D. hydei is markedly different from that found in D. melanogaster; D. hydei do not increase egg production, nor do they limit remating to additional males or change their diet after mating. Instead, hydei seem to display only subtle PMRs related to activity patterns, in a way distinct from those characterized in D. melanogaster. These changes seem to have impacted things like lifespan and sperm selection, and demonstrate the wide variety of choices that species can make and be successful in a given environment.

evolutionary biology↗

bioRxiv2025

Drosophila Video-assisted Activity Monitor (DrosoVAM): a versatile method for behavior monitoring

Drosophila melanogaster has been a pioneering model system for investigations into the genetic bases of behavior. Studies of circadian activity were some of the first behaviors investigated in flies. The DAM system by TriKinetics played a key role in establishing the fundamental feedback loop of the circadian clock. Although this method has many time proven to be extremely useful, it suffers from its simplification of activity to the interruption of an infrared beam. It is blind to fly movements not disrupting the beam and any modifications to this assay to achieve better resolution often requires the purchase of new and expensive modules. We required a relatively high-throughput system to explore the potential post-mating activity changes of larger Drosophila species. Rather than investing in a larger and more-complex DAM system, we designed a new monitoring system that is more versatile, economic and sensitive than DAM. This new system, called DrosoVAM (Drosophila Video-assisted Activity Monitoring), is simple to implement and cost efficient, using a Raspberry Pi-controlled infrared, digital video system to record multiple chambers and Python scripts that drives the deep learning software DeepLabCut, to track fly activity over multiple days.

animal behavior and cognition↗

bioRxiv2025

Multiomics profiling of zebrafish embryonic cell line PAC2 across growth phases to assess its relevance for toxicological studies

Permanent fish cell lines offer promising alternatives to traditional animal models for environmental risk assessment of chemicals. However, to facilitate their broader uptake into toxicity testing practice, a better understanding of functional capacities and expression of toxicologically relevant molecular targets is needed. Here, we present an extensive molecular profiling of the zebrafish embryonic cell line PAC2, combining global proteomics across cell population growth phases (over 7300 protein groups) with matched transcriptomics at exponential and stationary phase (over 14500 transcripts). Proteome coverage was sufficiently deep to reveal functional insights consistent with those derived from transcriptomics data, despite differences in the total number of measured genes. Major gene expression shifts detected upon transition from exponential to stationary cell population growth phase indicated reduction in DNA replication, translation, metabolism, and cell cycle regulation, along with increased stress responses, immune system responses, and extracellular matrix remodeling. Functional annotation revealed expression of core cellular processes along with a number of toxicologically relevant pathways, including xenobiotic metabolism, stress signaling, and nuclear receptors responsive to important chemical classes, such as steroids (e.g., estrogens, glucocorticoids) and chemicals known to disrupt lipid metabolism, e.g., through interaction with peroxisome proliferation activating receptors. These findings reinforce the potential of PAC2 cells to offer a versatile in vitro model for studying fish cell biology and omics-enhanced exploration of chemical toxicity mechanisms, aided by the well-developed molecular annotation in zebrafish. Moreover, the analysis approaches developed in this work offer a blueprint for molecular baseline characterization of other fish cell lines. This work thus strengthens the mechanistic foundation supporting the use of fish cell lines as alternative models in aquatic toxicity testing and risk assessment.

molecular biology↗

bioRxiv2022

Evolutionary trajectory of the physicochemical mechanism of interaction of SARS-CoV-2 spike protein with ACE2

SARS-CoV-2 infects cells by attachment to its receptor - the angiotensin converting enzyme 2 (ACE2). Regardless of the wealth of structural data, little is known about the physicochemical mechanism of interactions of the viral spike (S) protein with ACE2 and how this mechanism has evolved during the pandemic. Here, we applied experimental and computational approaches to characterize the molecular interaction of S proteins from SARS-CoV-2 variants of concern (VOC). Data on kinetics, activation- and equilibrium thermodynamics of binding of the receptor binding domain (RBD) from VOC with ACE2 as well as data from computational protein electrostatics revealed a profound remodeling of the physicochemical characteristics of the interaction during the evolution. Thus, as compared to RBDs from Wuhan strain and other VOC, Omicron RBD presented as a unique protein in terms of conformational dynamics and types of non-covalent forces driving the complex formation with ACE2. Viral evolution resulted in a restriction of the RBD structural dynamics, and a shift to a major role of polar forces for ACE2 binding. Further, we investigated how the reshaping of the physicochemical characteristics of interaction affect the binding specificity of S proteins. Data from various binding assays revealed that SARS-CoV-2 Wuhan and Omicron RBDs manifest capacity for promiscuous recognition of unrelated human proteins, but they harbor distinct reactivity patterns. These findings might contribute for mechanistic understanding of the viral tropism, and capacity to evade immune responses during evolution.

biochemistry↗

bioRxiv2021

Repression of the Hox gene abd-A by ELAV-mediated Transcriptional Interference

Intergenic transcription is a common feature of eukaryotic genomes and performs important and diverse cellular functions. Here, we investigate the iab-8 ncRNA from the Drosophila Bithorax Complex and show that this RNA is able to repress the transcription of genes located at its 3 end by a sequence-independent, transcriptional interference mechanism. Although this RNA is expressed in the early epidermis and CNS, we find that its repressive activity is limited to the CNS, where in wild-type embryos, it acts on the Hox gene, abd-A located immediately downstream of it. The CNS specificity is achieved through a 3 extension of the transcript, mediated by the neuronal-specific, RNA-binding protein, ELAV. Loss of ELAV activity eliminates the 3 extension and results in the ectopic activation of abd-A. Thus, a tissue-specific change in the length of a ncRNA is used to generate a precise pattern of gene expression in a higher eukaryote.

genetics↗