Biology subjects

Gal, J.

Publications and source records attributed to Gal, J..

4 recordsLinked to original sources

bioRxiv2025

First occurrence of parasitic isopod (Braga nasuta, Schioedte & Meinert, 1881) on ornamental fish in Europe

Parasitic crustaceans represent a significant threat to both freshwater and marine aquaculture, with several families capable of inducing severe diseases with high mortality rates and therefore significant economic losses. Among them, isopods of the genus Braga (Cymothoidae) are haematophagous parasites of neotropical fish, causing anaemia, tissue damage, and mortality. Braga nasuta, endemic to Brazil, has been reported from various hosts, including ornamental species exported worldwide. During routine examination of imported cardinal tetra (Paracheirodon axelrodi, Schultz, 1956), the authors detected that one of the fish harbored an adult male isopod ([~]6.21 mm long, 2.66 mm wide) attached anterior to the dorsal fin. Based on morphological identification, the parasite was identified as Braga nasuta. No secondary pathogens were observed in affected fish. Given the global trade in ornamental species, the introduction of B. nasuta into non-native regions underscores the importance of quarantine and parasite monitoring. While the potential ability of this parasite to establish populations in Europe requires further studies, vigilance is warranted to prevent potential spread and ecological impact. In this study, the authors document the first occurrence of B. nasuta in Europe, detected on a cardinal tetra (P. axelrodi) imported to a Hungarian public aquarium.

zoology↗

bioRxiv2025

Host environment shapes filarial parasites fitness and Wolbachia endosymbionts dynamics

Filarial nematodes, responsible for diseases like lymphatic filariasis and onchocerciasis, depend on symbiotic Wolbachia bacteria for reproduction and development. Using the Litomosoides sigmodontis rodent model, we investigated how host type-2 immunity influences Wolbachia dynamics and parasite development. Type-2 immune environments selectively reduce germline Wolbachia in female filariae from wild-type mice, a change associated with disrupted oogenesis, embryogenesis, and microfilarial production, while somatic Wolbachia remain unaffected. Antibiotic treatments achieving systemic Wolbachia clearance result in similar reproductive impairments. Notably, Wolbachia-free microfilariae are observed shortly after Wolbachia depletion, suggesting that early-stage embryogenesis can proceed temporarily before progressive germline dysfunction ensues. Wolbachia-free microfilariae develop into infective larvae in the vector, but stall beyond the L4 stage in vertebrate hosts, showing arrested growth and reproductive organ maturation defects in both male and female larvae. These findings highlight the variable dependency on Wolbachia across life stages and provide insights into host-parasite-endosymbiont interactions shaped by environmental pressures. Graphical abstract. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=136 SRC="FIGDIR/small/632327v1_ufig1.gif" ALT="Figure 1"> View larger version (30K): org.highwire.dtl.DTLVardef@98e008org.highwire.dtl.DTLVardef@9c32a7org.highwire.dtl.DTLVardef@c19000org.highwire.dtl.DTLVardef@1d523ad_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2023

Nesting flight statistics for wind turbine planning: a MoveApps workflow

As green, renewable energy is increasing by the installation of more and more wind turbines, the assessment of their impact on protected species has to be improved by more automatized, data-driven risk analyses. We have developed as set of two workflows to extract simple parameters for collision risk models from GPS tracks of sensitive bird species during nesting. The workflows have been integrated into the free MoveApps platform and are available there. The analysis code of all components of the workflows is openly available on GitHub, and improvement and adaption to other, similar requirements is encouraged. With three example data sets of white storks (WS), red kites (RK) and marsh harriers (MH), we illustrate how the workflows are used. The first workflow identifies nesting sites and time of nesting from the GPS tracks, the second workflow calculates flight speeds, flight duration, flight height and distance from the nest. Estimated flight speeds show low within species variability, with averages of 4.1 m/s (MH), 6.9 m/s (RK) and 10.9 m/s (WS). Extracted times of nesting are widely spread through the season and flight height and distance to the nest when in flight show large differences between individuals and years. Similar to the central evaluation distances around the nest required by national legislation, the 50% in-flight usage thresholds are 700 m (MH), 1100 m (RK) and 1400 m (WS). Flight height during nesting is rather low, on average 16 m (MH), 75 m (RK) and 193 m (WS) above the ground. These values can help to estimate collision risk with wind turbines for large birds in Central Europe during their nesting period. Finally, the developed MoveApps workflows (an possible adaptions) can be used to extract required parameters from tracking studies of any other vulnerable species or populations in an unbiased, automated manner to improve wind turbine placement in relation to nesting sites.

ecology↗

bioRxiv2022

S-Acylation Regulates the Membrane Association and Activity of Calpain-5

Calpain-5 (CAPN5) is a member of the calpain family of calcium-activated neutral thiol proteases. CAPN5 is partly membrane associated, despite its lack of a transmembrane domain. Unlike classical calpains, CAPN5 contains a C-terminal C2 domain. C2 domains often have affinity to lipids, mediating membrane association. We recently reported that the C2 domain of CAPN5 was essential for its membrane association and the activation of its autolytic activity. However, despite the removal of the C2 domain by autolysis, the N-terminal fragment of CAPN5 remained membrane associated. S-acylation, also referred to as S-palmitoylation, is a reversible post-translational lipid modification of cysteine residues that promotes membrane association of soluble proteins. In the present study several S-acylated cysteine residues were identified in CAPN5 with the acyl-PEG exchange method. Data reported here demonstrate that CAPN5 is S-acylated on up to three cysteine residues including Cys-4 and Cys-512, and likely Cys-507. The D589N mutation in a potential calcium binding loop within the C2 domain interfered with the S-acylation of CAPN5, likely preventing initial membrane association. Mutating specific cysteine residues of CAPN5 interfered with both its membrane association and the activation of CAPN5 autolysis. Taken together, our results suggest that the S-acylation of CAPN5 is critical for its membrane localization which appears to favor its enzymatic activity.

biochemistry↗