title: Isolation, characterization, and tissue-specific expression of GABA A receptor α1 subunit gene of Carassius auratus gibelio after avermectin treatment.
abstract: Carassius auratus gibelio has been widely cultivated in fish farms in China, with avermectin (AVM) being used to prevent parasite infection. Recently, AVM was found to pass through the Carassius auratus gibelio blood-brain barrier (BBB). Although AVM acts mainly through a GABA receptor and specifically the α1 subunit gene, the most common isoform of the GABA A receptor, which is widely expressed in brain neurons and has been studied in other fish, Carassius auratus gibelio GABA A receptor α1 subunit gene cloning, and whether AVM passes through the BBB to induce Carassius auratus gibelio GABA A receptor α1 subunit gene expression have not been studied. The aim of this study was to clone, sequence, and phylogenetically analyze the GABA A receptor α1 subunit gene and to investigate the correlation of its expression with neurotoxicity in brain, liver, and kidney after AVM treatment by quantitative real-time reverse transcription polymerase chain reaction. The α1 subunit gene was 1550 bp in length with an open reading frame of 1380 bp encoding a predicted protein with 459 amino acid residues. The gene contained 128 bp of 5' terminal untranslated region (URT) and 72 bp of 3' terminal UTR. The α1 subunit structural features conformed to the Cys-loop ligand-gated ion channels family, which includes a signal peptide, an extracellular domain at the N-terminal, and four transmembrane domains. The established phylogenetic tree indicated that the α1 subunits of Carassius auratus gibelio and Danio rerio were the most closely related to each other. The α1 subunit was found to be highly expressed in brain and ovary, and the α1 mRNA transcription level increased significantly in brain. Moreover, the higher the concentration of AVM was, the higher the GABA A receptor expression was, indicating that AVM can induce significant neurotoxicity to Carassius auratus gibelio. Therefore, the α1 subunit mRNA expression was positively correlated with the neurotoxicity of AVM in Carassius auratus gibelio. Our findings suggest that AVM should be used carefully in Carassius auratus gibelio farming, and other alternate antibiotics with lower toxicity should be investigated with respect to toxicity via the induction of GABA A receptor expression for fish farming.
authors: National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, No. 999 Hucheng Huan Road, Lingang New City, Pudong New District, Shanghai, 201306, People's Republic of China.
authors: Yini
authors: Y
authors: Zhao
authors: National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, No. 999 Hucheng Huan Road, Lingang New City, Pudong New District, Shanghai, 201306, People's Republic of China.
authors: Qi
authors: Q
authors: Sun
authors: National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, No. 999 Hucheng Huan Road, Lingang New City, Pudong New District, Shanghai, 201306, People's Republic of China.
authors: Kun
authors: K
authors: Hu
authors: National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, No. 999 Hucheng Huan Road, Lingang New City, Pudong New District, Shanghai, 201306, People's Republic of China.
authors: Jiming
authors: J
authors: Ruan
authors: National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, No. 999 Hucheng Huan Road, Lingang New City, Pudong New District, Shanghai, 201306, People's Republic of China. xly5352@126.com.
authors: Xianle
authors: X
authors: Yang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000977:Antiparasitic Agents / Q000494:pharmacology*; D001483:Base Sequence; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D029941:Fish Proteins / Q000235:genetics*; D015870:Gene Expression / Q000187:drug effects; D006054:Goldfish / Q000235:genetics*; D007559:Ivermectin / Q000031:analogs & derivatives* / Q000494:pharmacology; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000494:pharmacology*; D010802:Phylogeny; D020033:Protein Isoforms / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D011963:Receptors, GABA-A / Q000235:genetics*
chemical_list: D000977:Antiparasitic Agents; D018076:DNA, Complementary; D029941:Fish Proteins; D009498:Neurotoxins; D020033:Protein Isoforms; D012333:RNA, Messenger; D011963:Receptors, GABA-A; D007559:Ivermectin; C019264:avermectin
keywords: Avermectin; Carassius auratus gibelio; GABA A receptor α1 subunit; Phylogenetic tree; Sequence analysis; mRNA expression