Environmental Stress in Wild Armored Catfish Pterygoplichthys spp. Through CYP1A Gene Expression

Aquatic ecosystems are currently facing anthropogenic pollution, mainly derived from agricultural, industrial, and urban runoff, including heavy metals, polycyclic aromatic hydrocarbons (PHAs), pesticides, fertilizers, and untreated wastewater discharges. To understand the impact of environmental contamination on fish, this research compared cytochrome P450 1A (CYP1A) gene expression in armored catfish across three locations in the lower Grijalva–Usumacinta River basin known for varying levels of pollution. Samples from the Ribera Alta, the Bitzales River, and the Chaschoc lagoon were collected during the dry and rainy seasons. We isolated RNA from liver samples, which were subsequently converted to cDNA. We used quantitative PCR to analyze CYP1A gene expression. Results showed that, of the three locations, Ribera Alta demonstrated the highest expression during the rainy season. Only in Chaschoc Lagoon did we observe significant differences between seasons (p = 0.03). This indicates that seasonal factors and the presence of pollutants in the water bodies and sediments likely play a role in regulating CYP1A gene expression in this fish species.