Related Experiment Video
Updated: Jun 26, 2026
The Drosophila Imaginal Disc Tumor Model: Visualization and Quantification of Gene Expression and Tumor Invasiveness Using Genetic Mosaics
Published on: October 6, 2016
Effects of microcystin-LR on the expression of P-glycoprotein in Jenynsia multidentata
María Valeria Amé1, María Verónica Baroni, Lucas Nicolás Galanti
1Universidad Nacional de Córdoba-CONICET, Facultad Ciencias Químicas, Dto. Bioquímica Clínica-CIBICI, Haya de la Torre esq. Medina Allende, Ciudad Universitaria, 5000-Córdoba, Argentina. vame@mail.fcq.unc.edu.ar
Abstract:
The multixenobiotic resistance phenomenon (MXR) related to the P-glycoprotein multidrug transporter protein (P-gp) has been identified and characterized in several aquatic organisms. In the present work, we prove the presence of a P-gp in liver, gills and brain of Jenynsia multidentata by Western Blot and RT-PCR. A 170 kDa protein has been found in liver and gills while in brain a approximately 80 kDa protein has been detected. The partial nucleotide sequence obtained in this autochthonous fish showed high similarity ranging from 83% to 92% with other fishes. In addition, P-gp expression in this fish was evaluated after time and dose-dependent exposures to the cyanotoxin microcystin-LR. Individuals were exposed to MC-LR at concentrations of 2, 5 and 10 microg L(-1) for 24h and for 6, 12 and 24h at 2 microg L(-1) MC-LR. Changes in P-gp expression were observed in liver, gills and brain. However, this response was tissue specific. Only in gills of J. multidentata P-gp expression, measured either by real-time RT-PCR or Western Blot, was significantly higher compared to controls at most tested times and doses. A 3-fold increase with respect to controls was found at 12h by RT-PCR and after 24h by Western Blot. In dose-dependent experiments the maximum P-gp expression was observed at 2 microg L(-1) MC-LR, measured by both RT-PCR and Western Blot. In the liver, P-gp protein levels were significantly increased after 24h of exposure, at every toxin dose tested. Thus, probably longer exposures would show also significant increases in this tissue. Considering these results we can propose that P-gp belongs to the defence system involved in the response to MC-LR in J. multidentata.
Insights
The P-glycoprotein (P-gp) transporter protein, crucial for multixenobiotic resistance (MXR), was identified in Jenynsia multidentata. P-gp expression increased in gills and liver following exposure to the cyanotoxin microcystin-LR, suggesting a role in defense.
Area of Science:
- Environmental toxicology
- Molecular biology
- Aquatic toxicology
Background:
- The multixenobiotic resistance phenomenon (MXR) involves P-glycoprotein (P-gp) efflux pumps, protecting organisms from toxins.
- P-gp's role in aquatic species' defense against environmental contaminants is increasingly recognized.
Purpose of the Study:
- To confirm the presence and characterize P-gp in the South American fish Jenynsia multidentata.
- To investigate the impact of microcystin-LR (MC-LR) exposure on P-gp expression in different tissues of J. multidentata.
Main Methods:
- Western Blot and RT-PCR were used to detect and quantify P-gp in liver, gills, and brain.
- J. multidentata were exposed to varying concentrations and durations of MC-LR.
Main Results:
- P-gp was detected in liver (170 kDa), gills (170 kDa), and brain (approx. 80 kDa) of J. multidentata.
- MC-LR exposure significantly elevated P-gp expression in gills and, to a lesser extent, in the liver.
- Gills showed the most pronounced and consistent increase in P-gp expression in response to MC-LR.
Conclusions:
- P-gp is present in J. multidentata and plays a role in the fish's defense against the cyanotoxin MC-LR.
- The response of P-gp to MC-LR is tissue-specific, with gills exhibiting a strong induction.
